BIO-BASED LUBRICANT BASE STOCK AND DISTILLATE RANGE PRODUCTS AND PRODUCTION METHODS

FIELD OF THE INVENTION

This invention relates generally to lubricants base stocks and distillate range products derived from biomass, and to methods and systems for efficiently making biolubricant base stocks and distillate range products primarily comprised of acyclic hydrocarbons, from vegetable or crop oils and their derivatives.

All publications, patents, patent applications, and other references cited in this application are incorporated herein by reference in their entirety for all purposes and to the same extent as if each individual publication, patent, patent application or other reference was specifically and individually indicated to be incorporated by reference in its entirety for all purposes. Citation of a reference herein shall not be construed as an admission that such is prior art to the present invention.

PRIORITY TO RELATED APPLICATIONS

This application claims priority from US Provisional Application Serial Numbers 63/412,612 and 63/412,603, both of which were filed on October 3, 2022 and the contents of both of which are expressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

The term "synthetic" as it applies to fluids herein, refers to materials that are not normally found in nature, and that are manufactured by chemical processes, as opposed to being extracted from petroleum refinery streams, which extracted streams are generally referred to as being "petroleum-based. "

BioLubricants are of increasing interest for a number of reasons including: (1) they are produced from a renewable resource, (2) their production is less dependent on geopolitical considerations of global fossil energy suppliers, and (3) the net greenhouse gas emissions can be substantially reduced by virtue of CO2 uptake by biolubricant precursors together with the potential use of various carbon capture and utilization technologies in the production of the bio-feedstocks used to produce the biolubricants.

An easily-obtainable feedstock for biolubricant production is vegetable oil, which largely comprises triglycerides and some free fatty acids (FFA’s). The triglycerides are comprised of free fatty acid moi eties connected to a glycerin backbone, thus forming the triglyceride structure. The free fatty acids typically contain from 12 to 22 carbon atoms, with the C18 portion comprised of mono-unsaturated oleic acid, di-unsaturated linoleic acid and tri-unsubstituted linolenic acid.

A large number of studies have been conducted on use of triglycerides and their corresponding mono, di and tri alkyl ester analogs to produce hydrocarbon base stocks for use in various lubricant products. These routes typically use the initial conversion of the bio feedstock to light olefins and their subsequent conversion via know oligomerization or related pathways to higher hydrocarbons, or via various Hydroconversion sequences that generate products with high molecular weight but also with high levels of cycloparaffin and/or related polycyclic or aromatic molecules in the final hydrocarbon manifold. The latter usually lead to altered chemical or physical properties with negative effect on thermal or oxidative stability or environmental performance as measured by the products toxicity or biodegradability.

Mixtures of base stocks are commonly used to produce various lubricants, including lubricating oils for automobiles, industrial oils, turbine oils, greases, metal working fluids, etc. Individual base stocks can also be used as process oils, white oils, and heat transfer fluids. Finished lubricants generally consist of two components, base oils and additives. Base oil, which could be one or a mixture of base stocks, is the major constituent in these finished lubricants and contributes significantly to their performances, such as viscosity and viscosity index, volatility, stability, and low temperature performance. In general, a few base stocks are used to manufacture a wide variety of finished lubricants by varying the mixtures of individual base stocks and individual additives.

The American Petroleum Institute (API) categorizes base stocks in five groups based on their saturated hydrocarbon content, sulfur level, and viscosity index. Group I, II, and III base stocks are mostly derived from crude oil via extensive processing, such as solvent refining for Group I, and hydroprocessing for Group IT and Group TIT. Certain Group ITT base stocks can also be produced from synthetic hydrocarbon liquids via a Gas-to-Liquids process (GTL), and are obtained from natural gas, coal or other fossil resources. Group TV base stocks, the poly-alphaolefins (PAO), are produced by oligomerization of alpha olefins, such as 1 -decene. Group V base stocks include everything that does not belong to Groups I-IV, such as naphthenic base stocks, polyalkylene glycols (PAG), and esters. Most of the feedstocks for large-scale base stock manufacturing are non-renewable.

Automotive engine oils are by far the largest market for base stocks. The automotive industry has been placing more stringent performance specifications on engine oils due to requirements for lower emissions, long drain intervals, and better fuel economy. Specifically, automotive OEMs (original equipment manufacturer) have been pushing for the adoption of lower viscosity engine oils such as 0W-20 to OW-8, to lower friction losses and achieve fuel economy improvement. Base Oils with a lower Noack Volatility in an engine oil allows the formulation to retain the designed viscosity for longer operation times, allowing for increased fuel economy retention and longer drain intervals, as discussed in U.S. Pat. No. 6,300,291. Group I and Group IT's usage in OW-xx engine oils is highly limited because formulations blended with them cannot meet the performance specifications for OW-xx engine oils, leading to increased demands for Group ITT and Group TV base stocks.

Group ITT base stocks are mostly manufactured from vacuum gas oils (VGOs) through hydrocracking and catalytic dewaxing (e g. hydroisomerization). Group ITT base stocks can also be manufactured by catalytic dewaxing of slack waxes originating from solvent refining, or by catalytic dewaxing of waxes originating from Fischer-Tropsch synthesis from natural gas or coal based raw materials also known as Gas to Liquids base oils (GTL).

Manufacturing processes of Group ITT base stocks from VGOs is discussed in U.S. Pat. Nos. 5,993,644 and 6,974,535. Their boiling point distributions are typically higher when compared to PAOs of the same viscosity, causing them to have higher volatility than PAOs. Additionally, Group ITT base stocks typically have higher cold crank viscosity (i.e., dynamic viscosity according to ASTM D5293, CCS) than Group TV base stocks at equivalent viscosities.

GTL base stock processing is described in U.S. Pat. Nos. 6,420,618; US7,241,375; US 6,946,778; US 6,331 ,574; US6179994; US 6,165,949; US 6,096,940; US 5,965,475 and 7,282,134, which describe various processes for preparing base stocks from a Fischer-Tropsch synthesis product, the fractions of which are subjected to hydroisomerization to produce GTL base stocks.

Such structures and properties of GTL base stocks are described, for example, in U.S. Pat. Nos. 6,090,989 and 7,083,713, as well as U.S. Patent Application Publication 2005/0077208. In U.S. Patent Application Publication 2005/0077208, lubricant base stocks with optimized branching are described, which have alkyl branches concentrated toward the center of the molecules to improve the base stocks' cold flow properties. Nevertheless, pour points for GTL base stocks are typically worse than PAO or other synthetic hydrocarbon base stocks.

Polyalphaolefins (PAOs), or Group IV base oils, are produced by the polymerization of alphaolefms in the presence of a Friedel Crafts catalyst such as AlCl.sub.3, BF.sub.3, or BF.sub.3 complexes. For example, 1 -octene, 1 -decene, and 1 -dodecene have been used to manufacture PAOs that have a wide range of viscosities, varying from low molecular weight and low viscosity of about 2 cSt at 100. degree. C., to high molecular weight, viscous materials with viscosities exceeding 100 cSt at 100. degree. C. The polymerization reaction is typically conducted in the absence of hydrogen; the lubricant range products are thereafter polished or hydrogenated to reduce the residual unsaturation. Processes to produce PAO based lubricants are disclosed, for example, in U.S. Pat. Nos. 3,382,291; 4,172,855; 3,742,082; 3,780,128; 3,149,178; 4,956,122; 5,082,986; 7,456,329; 7,544,850. Prior efforts to prepare various PAOs that can meet the increasingly stringent performance requirements of modem lubricants and automotive engine oil particularly have favored low viscosity polyalphaolefin base stocks derived from 1 -decene, alone or in some blend with other mineral oils. However, the polyalphaolefins derived from 1 -decene can be prohibitively expensive due to its limited supply. Attempts to overcome the availability constraint of 1 -decene have led to the production of PAOs from C8 through C12 mixed alpha-olefin feeds, lowering the amount of 1 -decene that is needed to impart the properties. However, they still do not completely remove the requirement for providing 1 -decene as the predominate olefin feedstock due to performance concerns with resulting complexity and increased cost of production.

Similarly, previous efforts to use linear alphaolefms in the C14-C20 range made polyalphaolefins with unacceptably high pour points, which are unsuitable for use in a variety of lubricants, including 0W engine oils.

Therefore, there remains a need for a base stock composition having a set of properties that are all within commercially acceptable ranges, for example, for use in automotive and other applications, with such properties including viscosity, Noack volatility, and low temperature cold-cranking viscosity. Furthermore, there remains a need for base stock compositions having improved properties and methods of manufacture thereof, where the base stock compositions have reduced amounts of 1 -decene incorporated therein, and even preferably eliminate the use of 1 -decene in the manufacture thereof.

Almost all commercial current day distillate range hydrocarbon formulations having carbon numbers lower than C22 (DRH’s) are based on refinery extraction, severe hydrotreatment, by partly polymerizing linear olefins to produce low molecular weight linear alpha olefins, or by other olefin oligomerization and/or condensation reactions to produce higher molecular weight products including lubricant base stocks and greases. Fischer-Tropsch synthesis of distillates and waxy hydrocarbons, and various transesterification reactions of natural fatty acids with alcohol streams can also be employed.

Drilling Fluids: Typical current DRH’s are or are derived from internal olefins, alpha olefins, polyalphaolefins, paraffins, esters and blends of these materials. These fluids offer improved lubricity, thermal stability, and well-bore integrity.

The environmental properties of base drilling fluids in the prior art depend on the physical and chemical characteristics of the material. Olefin and paraffin base fluids and diesel will biodegrade aerobically. However, under anaerobic conditions, alpha olefin and internal olefin base fluids biodegrade more extensively (>50%) than paraffins and diesel (<5-20%). As a result, paraffin base fluids may persist in the environment for longer periods of time if they are not exposed to aerobic conditions. Ideally, base drilling fluids should be biodegradable under both aerobic and anaerobic conditions.

Aviation Fuels: Important characteristics of distillate range aviation fuel blend stocks, especially for jet fuels, include their low temperature properties, oxidative and thermal stability, energy content, and system compatibility, including effects on metal corrosion and integrity of seals and gaskets, toxicity and biodegradability. With today’s increasing environmental concerns, the greenhouse gas lifecycle analysis (LCA) has become an important characteristic of aviation fuels. It is extremely difficult or impossible to obtain a favorable balance of all of the above characteristics with current petroleum derived aviation fuels. For example, such aviation fuel blend stocks or typically contain significant amounts of poly-nuclear aromatics and complex polyunsaturates that are toxic to humans and animals. Accordingly, methods and systems for efficiently processing vegetable and/or crop oils into a broader range of lubricant base stocks and DHR’s with controlled performance and environmental properties, often simultaneously, would be highly beneficial.

SUMMARY OF THE INVENTION

A first aspect of the present invention is directed to methods and systems for processing triglyceride-containing, biologically-derived oils, comprising the conversion of triglycerides to monounsaturated free fatty acids (FFA’s) and the separation of these fatty acids for further conversion to dimerized intermediates. Such separation by type enables the efficient preparation of both lubricants and transportation fuels from a common source using a single integrated method and/or system.

The dimerized FFA’s are then converted via a specific multi step process, to a final hydrocarbon product lubricant base stock that retains as much as possible the basic structural features of the hydrocarbon backbone of the original FFA molecules (linearity of hydrocarbon backbones, degree of branching and length of average branches, cycloparaffin and aromatics content).

The present invention is also directed to methods and systems for producing primarily acyclic lubricant basestocks from triglyceride-containing, biologically-derived oils, comprising: providing a preferably >75% monounsaturated triglyceride feedstock; converting such triglyceride feedstock into free fatty acids via hydrolysis; converting the fatty acids to dimers having less than a 20% cyclic structure by heating the fatty acids in the presence of a bentonite clay catalyst at temperatures between 200-250°C; separating the remaining monomer fatty acids from the dimer fatty acids formed in the previous step; selectively hydrogenating said dimers to the degree necessary to fully saturate them and remove any residual double bonds; hydrodeoxygenating said saturated dimers to the minimum extent necessary to remove the oxygen therefrom by forming H2O or CO2; selectively hydro-isomerizing the deoxygenated dimers to the degree necessary to reduce the pour point of the produced basestock to a desired level; mildly hydrogenating the deoxygenated dimers to remove any residual double bonds; and optionally fractionating the resulting isomerized dimers by distillation to obtain hydrocarbon isomers of a desired carbon chain length range.

In some instances it may be preferable not to separate the remaining monomer fatty acids from the dimer fatty acids, but to hydrogenate the monomers and dimers together and to separate them later in the multistep process.

The step of providing a preferably >75% monounsaturated triglyceride feedstock may include partially hydrogenating a triglyceride-containing, biologically-derived oil to the extent necessary to eliminate any double or triple unsaturation but to retain the monounsaturated content.

If it is desired to shorten the carbon chain length of the dimers, the conditions under which the hydro-deoxygenating step is performed are controlled so that primarily CO2 is formed.

If the triglyceride-containing, biologically-derived oil comprises primarily soy, sunflower or canola, the free fatty acid monomers formed by the hydrolysis step largely have a C18 carbon chain length and the dimerizing, hydro-deoxygenating and hydrofining steps are performed under conditions such that the C36 dimers formed have less than 20% cyclic structure content, on a molar content basis, and a carbon chain length after the fractionation step of both even and odd numbered hydrocarbons in the range of C28 through C34 and the process conditions are controlled such that the produced lubricant basestocks have a kinematic viscosity at 100° C (KV100) of >3 cSt.

It is particularly beneficial for the carbon chain after the fractionation step to include both the even and odd numbered hydrocarbon molecules in the range in order to minimize the magnitude of discontinuities in physical and chemical properties of the adjacent carbon number molecules in the range and to make such physical and chemical properties of the final product more homogeneous.

If the triglyceride-containing, biologically-derived oil comprises primarily Camelina, it is possible to isolate a fraction of free fatty acids formed by the hydrolysis and/or transesterification step having a greater than 75% wt C22 carbon chain length and the dimerizing step is performed at temperatures between 225° C and 275° C and under conditions such that the dimers formed have less than 20% cyclic structure content and a carbon chain length after the fractionation step in the range of C 38 to C42 and the process conditions are controlled such that the produced lubricant basestocks have a KV100 of >4 cSt.

In some embodiments, the method of the invention comprises (a) providing a quantity of biologically-derived oil comprising triglycerides such as palmitoleic acid from Macadamia_nuts and Myristoleic acid from nutmeg; (b) processing the oils to hydrolyze at least some of the triglycerides and form free fatty acids (FFA’s) therefrom, wherein the fatty acids are primarily monounsaturated C16 and/or C14 fatty acids, respectively. The monounsaturated fatty acids are substantially converted into a diacid analog via catalytic conversion over clay containing catalysts wherein the acyclic acid dimers would contain 28 to 32 total carbon atoms that produce acyclic acid dimers. These dimers can then be converted into various hydrocarbon streams by a multi-step process that enables the basic molecular structure (linearity of hydrocarbon backbones, degree of branching and length of average branches, cycloparaffm and aromatics content) of the fatty acid backbones to be left largely intact in the ultimate hydrocarbon produced therefrom.

In a specific embodiment of the present invention, the triglyceride-containing, biologically- derived oil, is processed by (1) a treating the triglyceride feedstock to a controlled hydrogenation process to selectively hydrogenate the di and tri unsaturated analogs while leaving the mono unsaturated analogs intact, (2) subjecting the triglyceride to a conversion in a hydrolysis unit for treating the biologically-derived oil (bio-oil) to hydrolyze the triglycerides contained therein, thereby forming free fatty acids; (3) isolating the predominately monounsaturated fatty acids; (3) converting the monounsaturated fatty acids to their corresponding acyclic dimer acids, (4) subjecting the dimer acids to a selective hydrogenation step, (5) hydrotreating the saturated diacid in a hydroprocessing unit to hydro-deoxyenate the diacid, followed by fractional distillation and a final hydrofining step to remove any residual un-saturates from the hydrocarbon product.

In another embodiment of the present invention, the triglyceride-containing, biologically-derived oil, is processed by (1) a treating the triglyceride feedstock to a controlled hydrogenation process to selectively hydrogenate the di and tri unsaturated analogs while leaving the mono unsaturated analogs intact, (2) subjecting the triglyceride to a conversion in a transesterification unit for treating the biologically-derived oil (bio-oil) to esterify the triglycerides contained therein, thereby forming free fatty acid esters (FFAE’s); (3) isolating the predominately monounsaturated fatty acid esters; (3) converting the monounsaturated fatty acid esters to their corresponding acyclic dimer esters, (4) subjecting the dimer acid esters to a selective hydrogenation step, (5) hydrotreating the saturated diacid in a hydroprocessing unit to hydro-deoxyenate the diester, followed by fractional distillation and a final hydrofining step to remove any residual unsaturates from the hydrocarbon product.

Another important aspect of this invention relates to a produced saturated C28-C32 hydrocarbon mixture in which greater than 30% of the molecules have an odd carbon number, with a ratio of Branching Proximity to Branching Index (BP/BI) in the range of. Gtoreq (greater than or equal to) 0.58, and that retains as much as possible of the original molecular structure and associated beneficial properties of the FFA’s from which the hydrocarbon mixture was produced, and where on average over 80% of the molecules contain non-fossil carbon atoms, and the overall carbon intensity of the process from their production from seed to finished base stock is 20% or more lower than in a corresponding process for production of similar base stocks from fossil-based carbon sources. The saturated hydrocarbon mixture of the invention exhibits a cold crank simulator viscosity (CCS) vs Noack volatility relationship, which allows for the formulation of lower viscosity renewable engine oil base stocks and associated formulated lubricants with improved fuel economies.

In one embodiment, the hydrocarbon mixtures described herein are the product of dimerization of FFA’s and subsequent treatment of a multi-step Hydroconversion process. C12 to C22 monounsaturated FFA’s are dimerized to form a dimer acid adduct in the C24-C44 range. The resulting dimers are then subjected to a controlled multi-step Hydroconversion process to achieve the final branching structures described herein which consistently impart a surprising cold crank simulated viscosity (CCS) vs. Noack volatility relationship.

In accordance with another aspect of the present invention, there are provided methods and systems for processing triglyceride feeds and related derivatives into minimally branched acyclic distillate range hydrocarbons and to hydrocarbons produced thereby. An optional first aspect of this embodiment of the invention is directed to processes in which triglyceride-containing, biologically-derived oils, are converted to monounsaturated free fatty acids (FFA’s) or free fatty acid esters (FFAE’s) and the separation of them for further conversion to distillate range hydrocarbons. Such separation by type enables the efficient preparation of both distillate range fuels and industrial lubricants and transportation fuels from a common source using a single integrated method and/or system.

In embodiments of the invention in which the feed comprises contaminated triglyceride- containing, biologically derived oils such as used cooking oil, or oil contaminated with salts, minerals or metals, it can be preferable or necessary to initially purify the oils of such contaminants. U.S. Patent No. 10,071,322, which is hereby incorporated by reference in its entirety, discloses a system for both removing contaminants from the triglyceride -containing oil and converting the triglycerides into free fatty acids via hydrolysis is via a high-rate hydrothermal cleanup (HCU) process. The HCU process performs a rapid hydrolysis of renewable oils with a simultaneous reduction of inorganic and organic contaminants, such as salts, minerals, metals, asphaltenes, polymers, and coke precursors in renewable oils. The process is characterized by a very short residence time, high-temperature, high-pressure, turbulent flow, hydrothermal reaction. The HCU and integrated vapor-liquid separation system and process results in high yields of oil product that contains significantly reduced concentrations of inorganic and organic contaminants. The process may be operated to produce a concentrated clean glycerin byproduct and short-chain and long-chain free fatty acid (FFA) product streams. The integrated vapor-liquid separation system and process performs at near atmospheric pressure by taking advantage of the water employed in the cleanup process and the energy imparted by the HCU reactor and eliminates the need for vacuum distillation.

The foregoing has outlined rather broadly the features of the present invention in order that the detailed description of the invention that follows may be better understood. Additional aspects and advantages of the invention are described in the following detailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION A first aspect of the present invention is directed to methods and systems for processing triglyceride-containing, biologically-derived base oils together with lesser amounts of DRH’s byproducts, wherein such processing comprises conversion of triglycerides to monounsaturated free fatty acids and the multi-step conversion of these acids to predominantly isoparaffinic hydrocarbons that contain approximately equal molar amounts of even and odd carbon number containing molecules of C28 through C32. Such processing enables the efficient preparation of lubricants and transportation fuel as by-products from a common source using a single integrated method and/or system. Depending on the desired product slate, the operating conditions can be adjusted to increase the relative yield of DRH’s vs heavy lubricant base stocks.

The first step in our fully integrated process is preferably to control the overall molecular composition of the triglyceride feedstock via genetic selection or modification of conventional seed oil crops to have degree of mono-unsaturation of at least 75% and to limit overall chain length of the free fatty acid backbones. If the triglyceride feedstock has not been genetically selected or modified to be at least 75% mono-unsaturated, the triglyceride feedstock needs to be selectively partially hydrogenated to increase the degree of mono-unsaturation in the FFA backbones to at least 75% while minimizing the formation of fully saturated FFA’s. The 75%+ mono-unsaturated triglycerides are then hydrolyzed to produce the FFA as such. The FFA is then dimerized and subjected to an ultra-mild hydroconversion sequence to preserve as much as possible the original structure of the FFA backbone in the feedstock and to minimize cyclization and aromatization of ten molecules. Even if the triglyceride feedstock does have a degree of mono unsaturation that is greater than 75%, it is preferable or necessary in many applications to perform the initial partial hydrogenating step to further increase the mono-unsaturation content to as high as 90% or more.

The crops triglycerides from which the triglyceride feedstocks are obtained are preferably produced via a carbon farming technique to limit the overall carbon intensity of the renewable oils being produced, and the produced triglyceride feedstocks are preferably subjected to a refining step to limit the overall metals and non-triglyceride content of the oil produced. Refined bleached deodorized (RBD) triglycerides are preferably used as the triglyceride feedstocks in all embodiments described herein in order to avoid negative effects such as reduce catalyst life. In one embodiment of the invention, the triglycerides are harvested from seed crops that have been genetically selected or modified such that most of the fatty acids in the triglyceride’s from the seeds of a particular crop have the same carbon atom chain length, e.g. Cl 8 thereof. Examples of such crops include Plenish High Oleic Soy from Corteva, High Oleic Canola from Perdue, and High Oleic Sunflower from Avril and from genetically enhanced strains in the Ukraine.

If the triglyceride -containing feed also contains contaminants as in used cooking oil, or oil contaminated with salts, minerals or metals, it may be necessary to initially purify the feed oil of such contaminants. This step is preferably performed by the HCU process, in which the contaminated feedstock may be fed into a holding tank that allows for the equalization of flow and temperature control of the feedstock to maintain desired flow characteristics. The contaminated feedstock is pumped and heated to form a pressurized heated feed stream and combined with a pressurized heated water stream. Sufficient pressure is required to maintain the mixed liquid or vapor-liquid phases as required to accomplish the necessary cleanup based dependent upon the feedstock properties. Typical feedstock oils may become miscible with water at temperatures as low as 300° C and pressures as low as 1,250 psig. The combined pressurized heated stream is fed into a hydrothermal reactor that is configured and operated at high pressure to achieve turbulent flow conditions to optimize mixing and maximize heat transfer, but not so high a temperature as to cause feed conversion reactions to occur. Inorganic and heavy organic contaminants are liberated at HCU operating conditions and removed by the integrated HCU reactor and vapor-liquid separation systems. Effluent from the thermal reactor is cooled and depressurized, and then fed into an oil-water separator from which clean oil and process water are removed in separate streams.

In accordance with another embodiment of the present invention, the resulting distillate range synthetic fluid is produced from a controlled mixture of hydrocarbon components in which each hydrocarbon component of the mixture is produced from a separate preferably genetically selected or modified triglyceride containing seed in which substantially all of the fatty acids in the triglyceride’s of the seeds of each component are mono-unsaturated and have a single carbon atom chain length that is different from the single carbon atom chain length of the fatty acids in the triglyceride’s of the other component, preferably, e g., C14: l and C16: l, or C 12: 1 and a Cl 8: 1 . , Thus, in this embodiment, after hydrodeoxygenation and isomerization substantially all of the hydrocarbons in a component of the synthetic fluid will contain the same number of carbon atoms that is different from the number of carbon atoms of substantially all of the hydrocarbons in a second component of the synthetic fluid. The relative ratios of the single carbon atom number hydrocarbons in the mixture are selected to optimize the characteristics of the resulting synthetic fluid product for a given application. If the end product is a synthetic drilling or fracking fluid, the severity of the hydrotreatment of each component is preferably controlled such that the degree of cracking is minimized and the isomers generated are primarily monomethyl isoparaffins. If the end product is to be a jet fuel blend stock, the hydrotreatment of each component is preferably somewhat more severe in order to generate multiple branched isomers that have improved aerobic biodegradability and low temperature properties. The degree of hydrotreatment of each component must be controlled, however, to limit the degree of branching in order to preserve the original structure of the starting FFA backbone and to provide the required thermal and oxidative stability properties, and to minimize cracking.

Definitions. Certain terms and phrases are defined throughout this description as they are first used, while certain other terms used in this description are defined below:

The prefix "bio," as used herein, refers to an association with a renewable resource of biological origin, such resources generally being exclusive of fossil fuels.

A "biologically-derived oil," as defined herein, refers to any triglyceride-containing oil that is at least partially derived from a biological source such as, but not limited to, crops, vegetables, microalgae, and the like. Such oils may further comprise free fatty acids. The biological source is henceforth referred to as "biomass."

"Lipids," as defined herein, broadly refers to the class of molecules comprising fatty acids, and tri-, di-, and monoglycerides.

"Hydrolysis" of triglycerides yields free fatty acids and glycerol, such fatty acid species also commonly referred to as carboxylic acids (see above). "Transesterification," or simply "esterification," refers to the reaction between a fatty acid and an alcohol to yield an ester species.

"Hydroprocessing" refers to processes that react a triglyceride, mono- di or tri- ester derivative of a triglyceride, or a hydrocarbon-based material with hydrogen, typically under pressure and with a catalyst (hydroprocessing can be non-catalytic). Such processes include, but are not limited to, hydrodeoxygenation (of oxygenated species), hydrotreating, hydrocracking, hydroisomerization, hydrofining and hydrodewaxing.

"Isomerizing," as defined herein, refers to catalytic processes that typically convert n-alkanes to branched isomers.

"Transportation fuels," as defined herein, refer to hydrocarbon-based fuels suitable for consumption by vehicles. Such fuels include, but are not limited to, diesel, gasoline, jet fuel and the like.

"Diesel fuel," as used herein, is a material suitable for use in diesel engines and conforming to the current version at least one of the following specifications: ASTM D 975— "Standard Specification for Diesel Fuel Oils"; European Grade CEN 90; Japanese Fuel Standards JIS K 2204; The United States National Conference on Weights and Measures (NCWM) 1997 guidelines for premium diesel fuel; and The United States Engine Manufacturers Association recommended guideline for premium diesel fuel (FQP-1A).

"Lubricants," as used herein, are substances (usually a fluid under operating conditions) introduced between two moving surfaces so to reduce the friction and wear between them. Base oils used as motor oils are generally classified by the American Petroleum Institute as being mineral oils (Group I, II, and III) or synthetic oils (Group IV and V). See American Petroleum Institute (API) Publication Number 1509. "Pour point," as defined herein, represents the lowest temperature at which a fluid will pour or flow. See, e.g., ASTM International Standard Test Methods D 5950-96, D 6892-03, and D 97. "Cloud point," as defined herein, represents the temperature at which a fluid begins to phase separate due to crystal formation. See, e.g., ASTM Standard Test Methods D 5773-95, D 2500, D 5551, and D 5771.

Viscosity is the physical property that measures the fluidity of the base stock. Viscosity is a strong function of temperature. Two commonly used viscosity measurements are dynamic viscosity and kinematic viscosity. Dynamic viscosity measures the fluid's internal resistance to flow. Cold cranking simulator (CCS) viscosity at -35. degree. C. for engine oil is an example of dynamic viscosity measurements. The SI unit of dynamic viscosity is Pas. The traditional unit used is centipoise (cP), which is equal to 0.001 Pas (or 1 m Pas). The industry is slowly moving to SI units. Kinematic viscosity is the ratio of dynamic viscosity to density. The SI unit of kinematic viscosity is mm.sup.2/s. The other commonly used units in industry are centistokes (cSt) at 40. degree. C. (KV40) and 100°C. (KV100) and Saybolt Universal Second (SUS) at 100. degree. F. and 210. degree. F. Conveniently, 1 mm.sup.2/s equals 1 cSt. ASTM D5293 and D445 are the respective methods for CCS and kinematic viscosity measurements.

Viscosity Index (VI) is an empirical number used to measure the change in the base stock's kinematic viscosity as a function of temperature. The higher the VI, the less relative change is in viscosity with temperature. High VI base stocks are desired for most of the lubricant applications, especially in multigrade automotive engine oils and other automotive lubricants subject to large operating temperature variations. ASTM D2270 is a commonly accepted method to determine VI.

Pour point is the lowest temperature at which movement of the test specimen is observed. It is one of the most important properties for base stocks as most lubricants are designed to operate in the liquid phase. Low pour point is usually desirable, especially in cold weather lubrication. ASTM D97 is the standard manual method to measure pour point. It is being gradually replaced by automatic methods, such as ASTM D5950 and ASTM D6749. ASTM D5950 with 1. degree. C. testing interval is used for pour point measurement for the examples in this patent. Volatility is a measurement of oil loss from evaporation at an elevated temperature. It has become a very important specification due to emission and operating life concerns, especially for lighter grade base stocks. Volatility is dependent on the oil's molecular composition, especially at the front end of the boiling point curve. Noack (ASTM D5800) is a commonly accepted method to measure volatility for automotive lubricants. The Noack test method itself simulates evaporative loss in high temperature service, such as an operating internal combustion engine.

Boiling point distribution is the boiling point range that is defined by the True Boiling Points (TBP) at which 5% and 95% materials evaporates. It is measured by ASTM D2887 herein.

NMR Branching Analysis

Branching parameters measured by NMR spectroscopy for the hydrocarbon characterization include:

Branching Index (BI): the percentage of methyl hydrogens appearing in the chemical shift range of 0.5 to 1.05 ppm among all hydrogens appearing in the 1H NMR chemical range 0.5 to 2.1 ppm in an isoparaffinic hydrocarbon.

Branching Proximity (BP): the percentage of recurring methylene carbons which are four or more number of carbon atoms removed from an end group or branch appearing at .sup.13C NMR chemical shift 29.8 ppm.

Internal Alkyl Carbons: is the number of methyl, ethyl, or propyl carbons which are three or more carbons removed from end methyl carbons, that includes 3-methyl, 4-methyl, 5+ methyl, adjacent methyl, internal ethyl, n-propyl and unknown methyl appearing between ,sup, 13C NMR chemical shift 0.5 ppm and 22.0 ppm, except end methyl carbons appearing at 13.8 ppm.

5+ Methyl Carbons: is the number of methyl carbons attached to a methine carbon which is more than four carbons away from an end carbon appearing at 13C NMR chemical shift 19.6 ppm in an average isoparaffinic molecule.

The NMR spectra may be acquired using Bruker AVANCE 500 spectrometer using a 5 mm BBI probe. Each sample was mixed 1 : 1 (wt:wt) with CDCL. The ^X H NMR was recorded at 500.11 MHz and using a 9.0 .mu.s (30. degree.) pulse applied at 4 s intervals with 64 scans co-added for each spectrum. The .sup.13C NMR was recorded at 125.75 MHz using a 7.0 .mu.s pulse and with inverse gated decoupling, applied at 6 sec intervals with 4096 scans co-added for each spectrum. A small amount of 0.1 M Cr(acac).sub.3 was added as a relaxation agent and TMS was used as an internal standard.

The branching properties of the lubricant base stock samples of the present invention are determined according to the following six-step process. Procedure is provided in detail in US 20050077208 Al, which reference is incorporated herein in its entirety. The following procedure is slightly modified to characterize the current set of samples: 1) Identify the CH branch centers and the CH.sub.3 branch termination points using the DEPT Pulse sequence (Doddrell, D. T.; D. T. Pegg; M. R. Bendall, Journal of Magnetic Resonance 1982, 48, 323ff). 2) Verify the absence of carbons initiating multiple branches (quaternary carbons) using the APT pulse sequence (Patt, S. L.; J. N. Shoolery, Journal of Magnetic Resonance 1982, 46, 535ff ). 3) Assign the various branch carbon resonances to specific branch positions and lengths using tabulated and calculated values (Lindeman, L. P., Journal of Qualitative Analytical Chemistry 43, 1971 1245ff; Netzel, D. A., et. al., Fuel, 60, 1981, 307ff). Branch NMR Chemical Shift (ppm)

Quantify the relative frequency of branch occurrence at different carbon positions by comparing the integrated intensity of its terminal methyl carbon to the intensity of a single carbon (total integral/number of carbons per molecule in the mixture). For example, number of 5+ methyl branches per molecule is calculated from the signal intensity at a chemical shift of 19.6 ppm relative to intensity of a single carbon. For the unique case of the 2-methyl branch, where both the terminal and the branch methyl occur at the same resonance position, the intensity was divided by two before doing the frequency of branch occurrence calculation. If the 4-methyl branch fraction is calculated and tabulated, its contribution to the 5+ methyls must be subtracted to avoid double counting. Unknown methyl branches are calculated from contribution of signals that appear between 5.0 ppm and 22.5 ppm, however not including any additional branches. Calculate the Branching Index (BI) and Branching Proximity (BP) using the calculations described in U.S. Pat. No. 6,090,989, which is incorporated by reference herein in its entirety. Calculate the total internal alkyl branches per molecule by adding up the branches found in steps 3 and 4, except the 2-methyl branches. These branches would include 3-methyl, 4-methyl, 5+ methyl, internal ethyl, n-propyl, adjacent methyl and unknown methyl.

FIMS Analysis: The hydrocarbon distribution of the current invention is determined by FIMS (field ionization mass spectroscopy). FIMS spectra may be obtained on a Waters GCT-TOF mass spectrometer. The samples were introduced via a solid probe, which was heated from about 40. degree. C. to 500. degree. C. at a rate of 50. degree. C. per minute. The mass spectrometer was scanned from m/z 40 to m/z 1000 at a rate of 5 seconds per decade. The acquired mass spectra were summed to generate one averaged spectrum which provides carbon number distribution of paraffins and cycloparaffins containing up to six rings.

Hydrocarbon Structure and Properties

The structure of the hydrocarbon mixtures disclosed herein are characterized by FIMS and NMR. FIMS analysis is used to demonstrate the carbon number profile and shows that that more than 30% of the molecules in the hydrocarbon mixtures have an odd carbon number.

The unique branching structure of the hydrocarbon mixtures disclosed herein are characterized by NMR parameters, such as BP, BI, internal alkyl branching, and 5+ methyls. BP/BI of the hydrocarbon mixtures are in the range of .gtoreq 0.58. The 5+ methyls of the hydrocarbon mixtures average from 0.2 to 1.6 per molecule.

The hydrocarbon mixture can be classified into a carbon range, based on the carbon number distribution from C28 to C32 carbons. Generally, about or greater than 95% of the molecules present in each hydrocarbon mixture have carbon numbers within the specified range. Representative molecular structures for the C28 to C32 range can be defined based on the NMR and FIMS analysis. The unique branching structure and narrow carbon distribution of the hydrocarbon mixtures makes them suitable to be used as high-quality synthetic base oils, especially for low-viscosity engine oil applications. The hydrocarbon mixtures exhibit: a KV100 in the range of 3.0-15.0 cSt; a pour point in the range of -20 to -55. degree. C.; a Noack and CCS at -35. degree. C. relationship such that Noack for a sample with CCS between 1000 and 4000 at -35 degree C is .Igtoeq 0.9 x 2750 (CCS -35. degree. C.).sup.(-0.8).+2.

The VI for the C28-C32 hydrocarbon mixture is greater than 120 and may be as high as 145-155.

The Pour Point of the hydrocarbon mixture, in one embodiment ranges from 25 to -55. degree. C. and from 35 to -45. degree. C. in another embodiment.

In general, hydrocarbon mixtures disclosed above exhibit the following characteristics: at least 30% of the molecules have an odd carbon number according to FIMS; a KV100 in the range of 3.0-15.0 cSt; a pour point in the range of -20 to -55. degree. C.; a Noack and CCS @ -35. degree. C. relationship such that Noack is less than or equal t o 0.9 x 2750 (CCS @-35. degree. C.). sup. (-0.8). +2; with a BP/BI in the range of gtoreq.0.58 per molecule; and, on average from 0.2 to 1.6 5+ methyl branches per molecule.

Biolubricants and Paraffins from Triglyceride-Containing Precursors.

The method of the invention can include an initial step of obtaining a biologically-derived oil (bio-oil) comprising triglycerides by subjecting biomass to an extraction process to provide a sufficient quantity of bio-oil primarily comprising triglycerides. Typically, such an extraction process involves solvent extraction.

The bio-oil can originate from a biomass source such as seed crops, vegetables, microalgae, and combinations thereof. Those of skill in the art will recognize that generally any biological source of lipids can serve as the biomass from which the bio-oil can be obtained. It will be further appreciated that some such sources are more economical and more amenable to regional cultivation, and also that those sources from which food is not derived may be additionally attractive (so as not to be seen as competing with food).

The hydrolysis of the triglycerides can be accomplished using, e.g., well known acid- or basecatalyzed hydrolysis processes, such as, e.g., that described in Logan et al., U.S. Pat. No. 4,218,386, to yield free fatty acids and glycerol.

The above-described methods can further include a step of catalytically isomerizing at least some of the fatty acid derived hydrocarbons to yield an isomerized hydrocarbon mixture. Depending on process conditions such isomerizing step can result in lubricant base stocks and/or fuels having superior properties relative to those of the non-isomerized paraffinic (alkane) product (although the paraffinic product itself could find use as a lubricant, fuel or other commodity). The isomerizing step can be carried out using an isomerization catalyst such as Pt or Pd on a support such as SAPO-11, SM-3, SSZ-32, ZSM-23, ZSM-22, and similar such supports. The step of isomerizing the paraffinic product can also be accomplished using a Pt or Pd catalyst supported on an acidic support material such as beta or zeolite Y molecular sieves, SiO.sub.2, Al. sub.20. sub.3, SiO2-Al.sub.2O.sub.3, and combinations thereof.

The isomerization is typically carried out at a temperature between about 500. degree. F. and about 750. degree. F. The operating pressure is typically 200 to 2000 pounds-force per square inch gauge (psig), and more typically 200 psig to 1000 psig. Hydrogen flow rate is typically 50 to 5000 standard cubic feet/barrel (SCF/barrel).

The isomerizing step may also be conducted by contacting the paraffinic product with a fixed stationary bed of catalyst, with a fixed fluidized bed, or with a transport bed. In one presently contemplated embodiment, a trickle-bed operation is employed, wherein such feed is allowed to trickle through a stationary fixed bed, typically in the presence of hydrogen.

In some embodiments, the isomerized alkane mixture, comprised of hydrocarbons with <C22 total carbon atoms in the molecules, is better suited for use as a transportation fuel or drilling fluid. Typically, when such isomerized alkanes are used as/in a transportation fuel, they are predominately in the range of C6-C18 species. The isomerized alkane mixture can be mixed or admixed with existing transportation fuels in order to create new fuels or to modify the properties of existing fuels. Isomerization and blending can be used to modulate and maintain pour point and cloud point of the fuel, lubricant, or other product at suitable values.

In some embodiments, the ester by-products from the initial dimer feed preparation step are suitable for use as lubricants. Such species can be used neat, or they can be used as an additive to impart lubricity. Where the ester products are used as additives, they are blended with one or more species to collectively form an additive (vide infra).

In some of the above-described method embodiments, the hydrotreating steps may involve a hydroprocessing catalyst and a hydrogen-containing environment. In some such embodiments, the hydroprocessing catalyst is selected from the group consisting of cobalt-molybdenum (C— Mo) catalyst, nickel-molybdenum (N— Mo) catalyst, noble metal catalyst, and combinations thereof. Hydroprocessing conditions generally include temperature in the range 350. degree. C - 450. degree. C. and pressure in the range of about 4.8 mPa to about 15.2 mPa. For a general review of hydroprocessing, see, e.g., Rana et al, ”A Review of Recent Advances on Process Technologies for Upgrading of Heavy Oils and Residua Fuel,” vol. 86, pp. 1216-1231, 2007. For an example of how triglycerides can be Hydroprocessed to yield a paraffinic product, see Craig et al., U.S. Pat. No. 4,992,605.

Variations

In some embodiments, non-crop sources of triglyceride-containing oil can be mixed or admixed with the biologically-derived oil used herein. Additionally or alternatively, other sources of free fatty acids or free fatty esters (FFAE’s) could be similarly utilized.

A method for producing synthetic fluids from triglycerides harvested from genetically modified seed crops in which the fatty acids in the triglycerides from the seeds of a crop are predominately monounsaturated and have the same carbon atom chain length, preferably C12 up to Cl 8, and the synthetic fluids produced by the method. The triglycerides are Hydroprocessed to cleave the fatty acids from the glycol backbone and to hydrodeoxygenate and isomerize the fatty acids to form single carbon chain length isoparaffins having a controlled degree of branching with minimum cracking. Controlled mixtures of hydrocarbon components, in which each hydrocarbon component of the mixture has a different single carbon atom chain length, are produced. The relative ratios of the single carbon atom number hydrocarbons in the mixture are selected to optimize the characteristics of the synthetic fluid product for a given application, if the end product is a readily biodegradable hydrocarbon, the severity of the hydrotreatment is controlled such that the degree of cracking is minimized and the isomers generated are primarily monomethyl isoparaffins. If the end product is a jet fuel blend stock, the hydrotreatment is somewhat more severe in order to generate multiple branched isomers that have improved aerobic biodegradability and low temperature properties. The degree of hydrotreatment is controlled to limit the degree of branching in order to preserve the required thermal and oxidative stability properties, their volatility and viscosity, and to minimize cracking.

The use of C14 or C16 FFA or FFAE’s are preferred because it enables the elimination of a Hydroconversion step to selectively hydrocrack the end product to reduce its overall chain length and to more directly produce molecules in the desired molecular weight range.

EXAMPLES

Acyclic Bio-Lube Base Stock Produced from Faty Acid Dimers

EXPERIMENTAL

Production of Triglycerides with Ultra High C18;l Backbones:

Refined bleached deodorized (RBD) triglycerides are selectively hydrogenated to form products wherein the C18 mono-unsaturated (Cl 8: 1) content of the unsaturated pool of fatty acid ligands is >90% and the total content of fully saturated C18 acids is minimized.

Typical triglyceride starting material has the properties noted below:

The selective hydrogenation of a RBD soy oil (with total Na, K, Ca, Mg and P content at levels <25ppmw) over a modified Ni/SiO2 catalyst is achieved by operating at controlled conditions: 100-140 °C Rx temp / 40-50psig H2 / 0.20-0.023 wt% Ni on RBD feed with an 11-12.5% Ni/SiO2 catalyst as described in US 5,258,346 and US 9,045,410. In these runs, H2 is added to a stirred batch reactor on-demand (i.e. to maintain pressure as reactor pressure decreases) until the desired degree of selective hydrogenation of the di and tri -unsaturated moieties in the RBD are hydrogenated - whilst increasing the overall concentration of the mono-unsaturated moieties and minimizing their hydrogenation to fully saturated analogs. Fig. 1 shows a representative graph of the component weight percent content versus iodine value of the fatty acid components of an RBD soy oil for varying degrees of hydrogenation. As seen in Fig. 1, as the degree of hydrogenation increases from right to left, the percentage content of oleic acid in the soy oil increases until it reaches a peak at a value of about 68 and then decreases somewhat; and the percentage content of poly-unsaturates, consisting of the linoleic acid and linolenic acid, decreases from right to left with increasing selective hydrogenation.

Under controlled conditions we have shown that it is possible to achieve total Cl 8: 1 concentration levels of >92% in the unsaturated pool of FFA backbone moieties.

Production of Free Fatty Acids with High C18:l Content:

24

SUBSTITUTE SHEET (RULE 26) Hydrolysis of the triglycerides produced in the selective hydrogenation step can be hydrolyzed to produce free fatty acids according to commonly known procedures. The hydrolysis of the triglycerides can be accomplished using, e.g., well known acid- or base-catalyzed hydrolysis processes, such as, e.g., that described in Logan et al., U.S. Pat. No. 4,218,386, to yield free fatty acids and glycerol.

Production of Dimer Acid:

The primarily acyclic dimer acids of our process are produced from both poly- and monounsaturated fatty acids or free fatty acid esters, such as oleic acid or methyl oleate, in the presence of clay and a small amount of water (1-5 wt%). Preferred feeds are monounsatured. The latter is retained in the means of elevated pressure (5-11 atom). Crystalline clay minerals can be used, such as kaolinite, hectorite, but clays primarily composed of montmorillonite are preferred, in amounts of 1-20% (preferably 2-6. %wt) in the reaction mixture whilst maintaining a pH between 2 and 7. Dimerization starts at a temperature as low as 180°c, but temperatures of 200- 260°C are preferred for total reaction period of 2-4 hours. During the reaction the mixture is agitated to keep the catalyst in suspension. At the end of the heating period, the water is permitted to flash off in order to facilitate filtering, which is carried out after reducing the temperature to about 100-140°c. Then the unreacted monomeric feedstock is recovered by distillation of the reaction mixture. The dimer stream is recovered and can be used as is or subjected to a hydrogenation step to saturate any unsaturated C-C bonds in the dimer.

Production of Saturated Dimer Acids:

600g dodecane and 10g Pd/C catalyst suspension is put into the 5L CSTR autoclave. 900g of unsaturated dimer acid is added and the system flushed with nitrogen. The stirred system is slowly heated to 210~230 °C under hydrogen and maintained under those conditions for 4.5 hours under a total reaction pressure 4.0~5.0mPa. Fresh hydrogen is supplied to the process to maintain pressure until hydrogen absorption is complete.

The contents are cooled and pressure released to allow saturated acid dimer product to be isolated.

25

SUBSTITUTE SHEET (RULE 26) It is preferred that the FFA’s used to make the dimers be monounsaturated in order to maximize the acyclic structure of the dimer. The unsaturated dimers are then saturated to make them more resistant to hydrocracking in subsequent steps.

Hydrodeoxygenation (HDO) of the dimer acid or dimer ester:

A C18: 1 dimer acid is subjected to deoxygenation conditions using a sulfided Co-Mo or Ni-Mo hydro-deoxygenation catalyst (“HDO Catalyst”). The initial tests were performed in small downflow fixed bed reactor. A larger sample volume was produced in similar fashion during an extended run using a larger reactor setup. The final product was obtained by distillation to remove the C28-minus/C34-plus components.

Operation Conditions

Initial HDO runs were conducted in small fixed bed units. A three parallel-reactor set-up allowed testing of three conditions in unison. The catalyst was diluted in a 50/50 by volume mix with crushed glass beads. This set-up allowed combinations of reaction temperature, pressure, and liquid hourly space velocity (LHSV) to be evaluated with the same feed aliquot. The dimer feed properties are listed in Table 1.

Small Lab Reactor Setup: lOcc HDO catalyst + lOcc crushed glass (15x30 mesh size)

Larger Lab Reactor Setup: 43cc HDO catalyst + 43cc crushed glass (15x30 mesh size)

Table 1. Cl 8 Dimer Acid Physical and Chemical Properties

As stated in the SDS:

Physical state : Liquid

Appearance (room temperature) : Clear, Viscous. Color : Light yellow to dark yellow.

Odor : Characteristic odor. Mild odor. pH : < 7

Freezing point : < 20 °C

Boiling point : > 250 °C

26

SUBSTITUTE SHEET (RULE 26) Flash point : 293 °C (Cleveland open cup; Oleon QC; 06.2016)

Auto-ignition temperature : > 300 °C

Vapor pressure : < 0.01 hPa (20°C)

Density : 0.85 to 0.90

Solubility : Water: < 0.005 g/lOOml (25°C)

Log Pow : > 5 (est.)

Viscosity, dynamic : ca. 8000 cP (25°C)

VOC content : < 0.1 %

CofA for Dimer Acid

Acid Value, mg KOH/g 191.9

Water Content, % 0.01

Color Gardner 6.7

Viscosity at 25°C, mPa. s 5385

GLC, %(m)

Monomer & Intermediates 0.5

Dimer 90.3

Trimer 9.2

The process combinations utilized for the scoping study are shown in Table 2. 1 Dimer was diluted 50/50 with dodecane to lower viscosity for feed pumps

The catalyst was activated using dimethyl disulfide (DMDS) under sulfiding conditions. In general, dimer cracking increased as temperature was increased above the chosen starting temperature of 250°C. Significant cracking of the dimer into light hydrocarbons was observed at temperatures above 35O°C resulting in reduced C28-C32 yield. The starting lOOOpsig H2 pressure was reduced to 500psig to reduce the cracking effect. We discovered a sharp increase in dimer cracking at temperatures above 350°C at 500psig H2, with substantial cracking at 375°C. Lowering temperature to 300°C to reduce cracking results in less oxygen removal. .

In order to prevent an undesirably large degree of cracking to occur during the hydrodeoxygenation (HDO) step, it is desirable that an inhibitor be included with the dimers during the HDO and hydro-isomerizing steps in the form of phosphorus, nitrogen, and alkaline earth metal, and alkaline earth metal or a lower molecular length free fatty acid. The optimal yield of primarily acyclic hydrocarbon from the HDO step was found at temperatures between 335-365°C and preferably between 340-360°C. Optimal pressures for the HDO step are between 400-700psig, and preferably between 500 and 600psig.

Monomer-Dimer Acid Stream for Conversion to Isoparaffins and Renewable Lubricant

Base Stocks Dimer acids are typically produced via a coupling reaction over an acidic clay catalyst. Important process parameters, e. g. amount of catalyst, water content, stirring intensity, reaction time and pH of the catalyst all affect the selectivity of dimerization of oleic acid. A yield limit seems to exist at about 60 wt% (dimers and trimers). The remaining 40 wt% of the reaction mixture (monomers) contain only small amounts of cis- and trans-mono-unsaturated fatty acids, the rest of it being unidentified products, which can hardly be dimerized and cannot be hydrogenated with palladium on carbon. Infrared spectra of these monomers reveal the presence of small amounts of y-stearolactone and an increase in the number of methyl groups, which is probably the result of skeletal isomerization. The results indicate that a fairly large amount of saturated fatty acids is formed, most likely by hydrogen transfer. Typical production of the dimer acid includes fractionation of the lighter and heavier components via wiped film evaporators or thin film evaporators to generate a relatively pure dimer acid.

We have discovered that rather than separating the monomer and dimer/trimer streams before subjecting them to our novel hydrodeoxygenation step, the combined stream can be subjected to our selective catalytic hydrodeoxygenation isomerization step and converted to a mixture of mildly isomerized paraffin distillate range hydrocarbons and to a renewable lubricant base stock stream with low levels of aromatics.

BioLube Base Stock Product Evaluation

Based on the above runs, the following run conditions were selected for the larger test sample: 350°C/0.5 LHSV/500psig, and the runs conducted without amine addition. These conditions provided the optimal balance between excessive cracking and improved HDO activity compared to higher or lower temperatures. The raw product was cut into four carbon number ranges by distillation based on the reported boiling points of known alkane analogs, as shown in Table 3. The target product was distilled to a C28-C32 cut. The C28-C32 distillate (Cut 3) was submitted for carbon hydrogen nitrogen (CHN) analysis to estimate oxygen content by difference which resulted in ~1500wppm. The dimer feed oxygen content was calculated as 10.1wt% based on CHN analyses. Using these values, and if oxygen distribution were uniform across all cuts, this represents a 96% HDO value. Product Workup

The next step involves re-distilling Cut 3 to remove additional light molecules, color and odor bodies, and any associated oxygen containing molecules. The final product is re-distilled and the C28-C32 cut tested for 40°C & 100°C kinematic viscosities, Viscosity Index, GCD, and C13 NMR.

Hydrogenation of the product over a Pd/C catalyst is performed on the C28+ distillate to further reduce oxygen content. This sample is then subjected to the same analytical testing as noted above.

Hydroisomerization/Selective Hydrocracking of C28-C32 Hydrocarbon Product: The above-described methods can further include a step of catalytically isomerizing at least some of the fatty acid derived hydrocarbons to yield an isomerized hydrocarbon mixture. Depending on the pressure, temperature and flow rate of the process conditions, such isomerizing step can result in lubricant base stocks and/or fuels having superior properties (e.g. pour and cloud point, viscosity) relative to those of the non-isomerized paraffinic (alkane ligand containing) product (although the paraffinic product itself could find use as a lubricant, fuel or other commodity).

The isomerizing step can be carried out using an isomerization catalyst such as Pt or Pd on a support such as SAPO-11, SM-3, SSZ-32, ZSM-23, ZSM-22, and similar such supports. The step of isomerizing the paraffinic product can also be accomplished using a Pt or Pd catalyst supported on an acidic support material such as beta or zeolite Y molecular sieves, SiO.sub.2, Al.sub.2O.sub.3, SiO2-Al.sub.2O.sub.3, and combinations thereof.

The paraffinic components present in the original wax feed possess good V.I. characteristics but have relatively high pour points as a result of their paraffinic nature. The objective of this invention is, therefore, to affect a selective conversion of the C28-C32 stream to more highly branched analogs.

The catalyst used in this hydroisomerization step is one which has a high selectivity for the isomerization of waxy, linear or near linear paraffins to less waxy, isoparaffinic products. Catalysts of this type are bifunctional in character, comprising a metal component on a large pore size, porous support of relatively low acidity. The acidity is maintained at a low level in order to reduce conversion to products boiling outside the lube boiling range during this stage of the operation. In general terms, the catalyst should have an alpha value below 20 prior to metals addition, with preferred values below 10, and more preferred values below 5.

The alpha value is an approximate indication of the catalytic cracking activity of the catalyst compared to a standard catalyst. The alpha test gives the relative rate constant (rate of normal hexane conversion per volume of catalyst per unit time) of the test catalyst relative to the

31

SUBSTITUTE SHEET (RULE 26) standard catalyst which is taken as an alpha of 1 (Rate Constant=0.016 sec ^-1 ). The alpha test is described in U.S. Pat. No. 3,354,078 and in J. Catalysis, 4, 527 (1965); 6, 278 (1966); and 61, 395 (1980), to which reference is made for a description of the test. The experimental conditions of the test used to determine the alpha values referred to in this specification include a constant temperature of 538° C. and a variable flow rate as described in detail in I. Catalysis, 61, 395 (1980).

The hydroisomerization catalyst comprises a large pore zeolite metal. The large pore zeolite is supported by a porous binder. Large pore zeolites usually have at least one pore channel consisting of twelve-membered oxygen rings. Large pore zeolites usually have at least one pore channel with a major dimension greater than 7A and a Constraint Index of less than 1. Zeolites suitable for use in the instant invention are listed below:

CI (at test temperature)

ZSM-4 0.5 (316° C.)

MCM-22 0.6-1.5 (399° F. -454° C.)

TEA Mordenite 0.4 (316° C.)

REY 0.4 (316° C.)

Amorphous Silica-alumina 0.6 (538° C.)

Dealuminized Y 0.5 (510° C.)

Zeolite Beta 0.6-2.0 (316° C.-399 ⁰ C.)

ZSM-20 0.5 (371° C.)

Mordenite 0.5 (316° C.)

A preferred hydroisomerization catalyst employs zeolite beta since this zeolite has been shown to possess outstanding activity for paraffin isomerization in the presence of aromatics, as disclosed in U.S. Pat. No. 4,419,220. Zeolite beta possesses a constraint index between 0.60 and 2.0 at temperatures between 316° C. and 399° C. although Constraint Indexes less than 1 are preferred. The low acidity forms of zeolite beta used in this invention may be obtained by synthesis of a

32

SUBSTITUTE SHEET (RULE 26) highly siliceous form of the zeolite e.g with a silica-alumina ratio above about 500:1. The catalysts of our Hydroisomerization step are prepared in the absence of boron. The absence of boron simplifies preparation of the catalyst and facilitates later addition of phosphorus. Steaming zeolites of lower silica-alumina ratio to the requisite acidity level has been used in the prior art to increase the silica-alumina ratio, however, steamed catalysts are not effective in the instant invention. They may also be obtained by extraction with acids such as dicarboxylic acid, as disclosed in U.S. Pat. No. 5,200,168. This patent discloses the synthesis of dealuminated zeolite beta by oxalic acid extraction. U.S. Pat. No. 5,238,677 discloses the synthesis of dealuminated mordenite by oxalic acid extracting. U.S. Pat. No. 5,164,169 discloses the preparation of highly siliceous zeolite beta employing a chelating agent such as tertiary alkenolamines in the synthesis mixture.

The zeolites possess a framework silica-alumina ratio of 50: 1 or above. Preferably the silica- alumina ratio is above 200:1 and more preferably the silica-alumina ratio is greater than 600: 1. In the prior art, the desired silica-alumina ratio was obtained by severely steaming the catalyst. The high-silica alumina ratio is obtained, in the present embodiment however, by preparing the catalyst as described in U.S. Pat. No. 5,232,579. A catalyst may be synthesized with a high silica-alumina ratio. The catalyst which is synthesized with a high silica-alumina ratio provides superior results to a steamed catalyst in this invention.

Catalyst Properties

Catalyst acidity may be reduced by the introduction of nitrogen compounds, e.g. NH3 or organic nitrogen compounds, with the feed to the hydroisomerization catalyst. However, the total nitrogen content of the feed should not exceed 100 ppm and should preferably be less than 20 ppm. The catalyst may also contain metals which reduce the number of strong acid sites of the catalyst and improve the selectivity of isomerization reactions to cracking reactions. Metals which are preferred for this purpose are those belong to the class of Group 1 A and Group IIA metals such as potassium, calcium and magnesium.

33

SUBSTITUTE SHEET (RULE 26) The zeolite will be composites with a matrix material to form the finished catalyst and for this purpose conventional very low-acidity matrix materials such as alumina, silica-alumina and silica are suitable although aluminas such as alpha boehmite (alpha alumina monohydrate) may also be used, provided that they do not confer any substantial degree of acidic activity on the matrixed catalyst. The zeolite is usually composites with the matrix in amounts from 80:20 to 20:80 by weight, typically from 80:20 to 50:50 zeolite:matrix. Compositing may be done by conventional means including mulling the materials together followed by extrusion into the desired finished catalyst particles. A preferred method for extruding the zeolite with silica as a binder is disclosed in U.S. Pat. No. 4,582,815. If the catalyst is to be steamed in order to achieve the desired low acidity, it is performed after the catalyst has been formulated with the binder, as is conventional. The preferred binder for the steamed catalyst is alumina.

The hydroisomerization catalyst also includes a metal component in order to promote the desired hydroisomerization reactions which, proceeding through unsaturated transitional species, require mediation by a hydrogenation-dehydrogenation component. In order to maximize the isomerization activity of the catalyst, metals having a strong hydrogenation function are preferred and for this reason, platinum and the other noble metals such as rhenium, gold, and palladium are given a preference. The amount of the noble metal hydrogenation component is typically in the range 0.1 to 5 weight percent of the total catalyst, usually from 0.1 to 2 weight percent. The platinum may be incorporated into the catalyst by conventional techniques including ion exchange with complex platinum cations such as platinum tetraamine or by impregnation with solutions of soluble platinum compounds, for example, with platinum tetraammine salts such as platinum tetraamminechloride. The catalyst may be subjected to a final calcination under conventional conditions in order to convert the noble metal to its reduced form and to confer the required mechanical strength on the catalyst. Prior to use the catalyst may be subjected to presulfiding as described above for the hydrocracking pretreatment catalyst.

Hydroisomerization Conditions

The conditions for the hydroisomerization step (also called the isomerization step) are adjusted to achieve the objective of isomerizing the waxy, linear and near-linear paraffinic components in

34

SUBSTITUTE SHEET (RULE 26) the waxy feed to less waxy but high V I. isoparaffinic materials of relatively lower pour point. This end is achieved while minimizing conversion to non-lube boiling range products (usually 650° F.-(345° C. -) materials). Since the catalyst used for the hydroisomerization has a low acidity, conversion to lower boiling products is usually at a relatively low level and by appropriate selection of severity, the operation of the process may be optimized for isomerization over cracking. At conventional space velocities of about 1, using a Pt/zeolite beta catalyst with an alpha value below 20, temperatures for the hydroisomerization will typically be in the range of about 570° to about 780° F. (about 300° to 415° C.) with conversion to 650° F — typically being from about 5 to 30 weight percent, more usually 10 to 25 weight percent, of the waxy feed. Approximately 40 to 90 percent of the wax in the feed is converted in the isomerization step. However, temperatures may be used outside this range, for example, as low as about 500° F. (260° C.) and up to about 800° F. (about 425° C.) although the higher temperatures will usually not be preferred since they will be associated with a lower isomerization selectivity and the production of less stable lube products as a result of the hydrogenation reactions being thermodynamically less favored at progressively higher operating temperatures. Space velocities will typically be in the range of 0.5 to 2 LHSV (hr. ^-1 ). The pour point of the effluent from the hydroisomerization step is in the range from 30° to 110° F., preferably in the range from 40° to 100° F.

The hydroisomerization is operated at hydrogen partial pressures (reactor inlet) of at least 800 psig (about 5516 kPa), usually 800 to 3000 psig (5516 to 20785 kPa) and in most cases 800-2500 psig (5516 to 17340 kPa). Hydrogen circulation rates are usually in the range of about 500 to 5000 SCF/Bbl (about 90 to 900 n.1.1. ^-1 ). Since some saturation of aromatic components present in the original feed takes place in the presence of the noble metal hydrogenation component on the catalyst, hydrogen is consumed in the hydroisomerization even though the desired isomerization reactions are in hydrogen balance; for this reason, hydrogen circulation rates may need to be adjusted in accordance with the aromatic content of the feed and also with the temperature used in the hydroisomerization since higher temperatures will be associated with a higher level of cracking and, consequently, with a higher level of olefin production, some of which will be in the lube boiling range so that product stability will need to be assured by saturation. Hydrogen circulation rates of at least 1000 SCF/Bbl (about 180 n.1.1. ^-1 ) will normally

35

SUBSTITUTE SHEET (RULE 26) provide sufficient hydrogen to compensate for the expected hydrogen consumption as well as to ensure a low rate of catalyst aging.

An interbed quench is desirable to maintain temperature in the process. Cold hydrogen is generally used as the quench, but a liquid quench, usually recycled product, may also be used.

Dewaxing

Although a final dewaxing step will normally not be necessary in order to achieve the desired product pour point, it is a notable feature of the present process that the extent of dewaxing required is relatively small. This will be especially true for those operations that employ C12:l, C14: 1 and/or C16: 1 feedstocks, as the inclusion of those feedstocks generates dimers that are closer to the desired carbon content of the final hydrocarbon product. C 12: 1 feedstock is available, e.g., from Coriander or Lauraceae. Typically, the loss during the final dewaxing step will be no more than 15-20 weight percent of the dewaxer feed and may be lower. Either catalytic dewaxing or solvent dewaxing may be used at this point and if a solvent dewaxer is used, the removed wax may be recycled to the hydroisomerization for a second pass through the isomerization step. The demands on the dewaxer unit for the product are relatively low, and in this respect, the present process provides a significant improvement over the process employing solely amorphous catalysts where a significant degree of dewaxing is required. The high isomerization selectivity of the zeolite catalysts enables high single pass wax conversions to be achieved, typically about 80% as compared to 50% for the amorphous catalyst process so that unit throughput is significantly enhanced.

A shape-selective dewaxing catalyst maybe alternately employed rather than a solvent dewaxing approach. This catalyst removes the n-paraffms together with the waxy, slightly branched chain paraffins, while leaving the more branched chain iso-paraffins in the process stream. Shape- selective catalytic dewaxing processes employ catalysts which are more highly selective for removal of n-paraffms and slightly branched chain paraffins than is the isomerization catalyst, zeolite beta. This phase of the synergistic process is therefore carried out as described in U.S. Pat. No. 4,919,788, to which reference is made for a description of this phase. The catalytic

36

SUBSTITUTE SHEET (RULE 26) PCT/US23/34260 14 December 2023 (14.12.2023) dewaxing step in the present process is carried out with a constrained, shape selective dewaxing catalyst based on a constrained intermediate pore material, such as an alumino-phosphate. A constrained intermediate crystalline material has at least one channel of 10-membered oxygen rings with any intersecting channel having 8-membered rings. ZSM-23 is the preferred zeolite for this purpose although other highly shape-selective zeolites such as ZSM-22 or the synthetic ferrierite ZSM-35 may also be used, especially with lighter stocks. Silicoaluminophosphates such as SAPO-11 and SAPO-41 may be used as selective dewaxing catalysts.

The preferred catalysts for use as the dewaxing catalysts are the relatively constrained intermediate pore size zeolites. Such preferred zeolites have a Constraint Index in the range of 1- 12, as determined by the method described in U.S. Pat. No. 4,016,218. These preferred zeolites are also characterized by specific sorption properties related to their relatively constrained diffusion characteristics. These sorption characteristics are those which are set out in U.S. Pat. No. 4,810,357 for the zeolites such as zeolite ZSM-22, ZSM-23, ZSM-35 and ferrierite. These zeolites have pore openings which result in a specific combination of sorption properties, namely, (1) a ratio of sorption of n-hexane to o-xylene, on a volume percent basis, of greater than about 3, wherein sorption is determined at a P/P _o of 0.1 and at a temperature of 50° C. for n- hexane and 80° C. for o-xylene and (2) by the ability of selectively cracking 3 -methylpentane (3MP) in preference to the doubly branched 2, 3 -dimethylbutane (DMB) at 1000° F. and 1 atmosphere pressure from a 1/1/1 weight ratio mixture of n-hexane/3-methylpentane/2,3- dimethylbutane, with the ratio of rate constants 1<3\ID /koMB determined at a temperature of 1000° F. being in excess of about 2.

The individual steps in our process can be practiced in individual reactors, or they can be combined into a single multistage trickle bed vessel such as that offered in the Hydroflex reactor system developed by Haldor Topsoe. Other multistage hydrotreating reactors can also be utilized in our process, especially if they are able to be retrofitted to operate under the conditions of our process.

Camelina Based Process Configuration

37

SUBSTITUTE SHEET (RULE 26) Camelina crops used to produce novel synthetic fluids of the invention are genetically selected or modified in such a way that the fatty acids in the triglyceride's of the seeds are predominantly of a specific carbon chain length, preferably Cl 8, C20 and/or C22. In a preferred embodiment of the method of invention, the seed crop used to produce the triglycerides matures rapidly and can be interspersed with the successive plantings of another crop, such as a food crop. Genetically selected or modified camelina is a rapidly growing seed crop that can be an excellent source of triglycerides in the desired carbon chain lengths. Advantageously, it can be produced in rotation with traditional food crops, such as wheat, to maximize the CO2 consumption rate of a given acre of land. The cellulosic material that remains after the TGF”s in the seeds are isolated from the crop can be gasified to produce syngas to supply hydrogen for later hydroprocessing steps, or it can be converted into a specific high purity biochar for use in soil amendments.

Genetically selected or modified camelina is a particularly preferred seed crop for use in the present invention because they go from planting of the seeds to harvest within 90 days, requires minimal water, and do well in semi-arid soils, and it provides a feedstock high in C20 and C22 FFA moieties. Also, the residual cellulosic material can be used as a component for biofertilizer or as an animal fodder.

The method of the invention is especially advantageous from environmental point of view because it is capable of achieving a net negative greenhouse gas footprint. The extent to which it is negative will depend on the specific seed crop used, the amount of fertilizer and water needed to grow the crop, and the impact on the and being used versus what it was being used for before the seed crop was planted.

The genetic modification of the sed cops such camelina to have increased triglyceride oil content, selective medium FFA chain length or specific single carbon chain length (or combinations thereof) of the fatty acid moieties may be performed by any method known to those skilled in the art. Techniques capable of performing such genetic modifications are disclosed e g., in US11168331, US11053480, US9035131, US9080134, US8319020, US8319021 US8748679, and in international applications WO/2009/125401, WO/2009/109054, WO/2009/147127 or WO/2009/129582, the disclosures of which are hereby incorporated by reference in their entirety for all purposes.

In one illustrative procedure, the fatty acids are cleaved using a thermochemical process in which the triglycerides or heated in an aqueous acidic solution or an aqueous basic solution, preferably in the presence of a catalyst. One such thermochemical process for cleaving fatty acids from a glycerol backbone is described in Myllyoja et al, U.S. patent application Ser. No. 11/477,922, which is hereby incorporated by reference in its entirety for all purposes. In one embodiment of our invention, the cleavage process step involves a decarboxylation reaction as described in Myllyoja.

Alternatively, the process may comprise the disassembly of a medium chain fatty acid source from glycerol by decarboxylation of the fatty acid chains while still attached to the glycerol backbone, thus simultaneously cleaving the fatty acid group and producing glycerol and one or more hydrocarbon products. In such case, the hydrocarbon product will be one carbon shorter in chain length than the original fatty acid.

In another embodiment, the fatty acid chains may be partially reduced while still attached to the glycerol backbone, thereby producing glycerol and the hydrocarbon product, in such case, the hydrocarbon product, prior to isomerization, has the same carbon chain length as the original fatty acid coupled to the triglycerides. The reduction is preferably performed in the presence of hydrogen and any suitable catalyst. In an additional embodiment, the triglycerides may be disassembled by chemical reduction of the glycerol backbone, thereby producing the hydrocarbons and propane, propanol, propanediol or other glycerol-derived products or combinations thereof.

The conversion of the triglycerides may be performed in the presence of the catalyst at temperatures from about 250. degree. C. to about 350. degree. C., preferably about 280. degree. C. to about 320. degree. C., but more preferably about 300. degree. C. The conversion of the Triglycerides is preferably performed in the presence of hydrogen, preferably at a gauge pressure ranging from about 50 psig to about 200 psig, preferably ranging from about 75 psig to about 150 psig, more preferably from about 90 psig to about 125 psig. The catalyst is most preferably prepared for usage by pretreatment with hydrogen, resulting in reduction of the active metal. The reduction of catalyst is performed at an elevated temperature resulting in removal of water during the reduction step.

Alternatively, fatty acids may be cleaved from the glycerol by an enzymatic process such as the process described in U.S. Pat. No. 4,394,445, herein incorporated by reference in its entirety for all purposes, or other biological processes known in the art. Examples of enzymes that may be used include, without limitation, esterases, lipases, proteases, or combinations thereof. As used herein, a “biological process" is any process utilizing biological organisms (e.g. bacteria, algae, etc.) to accomplish the desired reaction. In another embodiment, the fatty acids may be cleaved from the glycerol backbone by acid-catalyzed hydrolysis of the glycerides in the triglycerides.

After cleavage of the fatty acids from the glycerol, the glycerol may be separated from the fatty acids. The separation may be accomplished by various conventional methods including, without limitation, liquid-liquid extraction, supercritical solvent extraction, distillation, membrane fdtration, acidulation, centrifugation, by gravity separation, or combinations thereof. Once separated from the fatty acids, the separated glycerol may be used for further reforming or other purposes.

If the end product is to be an automotive lubricant base stock, the triglycerides may be Isolated separately from each genetically modified or selected seed crop, are dimerized and then Hydroprocessed to hydrodeoxygenate and isomerize each dimer acid to generate corresponding component isoparaffins, substantially all of the molecules of each component isoparaffin containing the same number of carbon atoms, preferably between Cl 8, C20 and/or C22 of the original monomer used to produce the dimer acid. Isoparaffin components containing different single numbers of carbon atoms are mixed in controlled proportions to form a base stock with controlled viscomertric and vapor pressure. In accordance with the method of the invention, the severity of the isomerization hydrotreatment of each component is controlled such that the degree of cracking is minimized and the isomers generated are primarily monomethyl branched isomers. Especially in the case where the end product is to be a lubricant base stock, it is desirable that at least 30% of the base stock molecules have an odd carbon number. This is achieved in our HDO and Selective Hydrocracking steps where the feed dimer of even carbon number is subjected to a hydrocracking or hydrogenolysis reaction to break off one or a combination of Cl, C2, C3 or C4 light hydrocarbons such that an odd number of carbons remain.

In the case where distillate fuels with the best low temperature properties are produced, it is desirable to eliminate essentially all the linear molecules that would otherwise present problems with pour and cloud point.

If the end of product is to be a jet fuel blend stock, the isomerization hydrotreatment is preferably somewhat more severe in order to generate multiple branched isomers that have improved aerobic biodegradability and low temperature properties. The degree of hydrotreatment of each component must be controlled, however, to limit the degree of branching in order to preserve the required thermal and oxidative stability properties, and to minimize cracking.

In general, the isomerization hydrotreatment for each component should be the minimum required to obtain the required low temperature properties, e.g., a freeze point of less than - 47. degree. C. in practice, the appropriate degree of hydrotreatment and isomerization for the components of the synthetic fluids of the invention depends on the carbon chain length of the fatty acid and can be determined by simple experimentation. For instance, a series of tests could be run for a given component using different severities of hydrotreatment and the hydrocarbon product produced by each test run would be tested to identify the minimum hydrotreatment conditions that achieve the required freeze point. The optimum conditions will vary from feed to feed, e.g., with the specific carbon chain length of the fatty acid in the triglycerides, and from catalyst to catalyst.

A chemiometric study would then be performed in which the components are mixed in different proportions to determine the optimal mixture or range of mixtures that meet the requirements of the applicable specifications, e.g., ASTM 7566, such as viscometric properties, cloud point and thermal and oxidative stability. Once those conditions are determined, they would be used in the normal production run to generate large scale batches of product. This method provides a selfdefining approach that maximizes performance for any combination of the variables significant to a given application. The fact that, in accordance with the invention, substantially all of the fatty acids in the TGF”s of a particular feed have the same carbon chain length allows the determination of an optimal set of processing conditions for a given feed that results in a much more precisely controlled product composition than would be possible with a feed containing fatty acids of varying carbon chain lengths.

The novel synthetic fluids produced by the method of the invention are biodegradable, due to the controlled degree of cyclization and aromatization, under the conditions of production, are nontoxic and fully renewable, and do not require any petroleum based components to function as lubricant base stocks and/or fuel blend stocks, thereby substantially reducing the overall GHG footprint of the production and use of the synthetic fluids produced by the method of the invention.

The novel camelina produced synthetic fluids of the invention consist essentially of controlled mixtures of preferably Cl 8, C20 and/or C22 isoparaffins in the case of fuels, or their dimer analogs in the case of lubricants, in which the molecules have controlled degrees of branching, and a minimized content of shorter chain molecules resulting from cracking during hydroprocessing. The processing condition for the isoparaffin components of the fluids are preferably controlled such that each of the components, and therefore the blended fluid, is substantially free of poly-nuclear aromatics and complex polyunsaturates. The controlled relative amounts of Cl 8, C20 or C22 molecules in the synthetic fluids of the invention result in fluids having optimal combinations of properties for a given application such as lubricant base stocks or aviation fuels. The fact that the fluid is substantially free of poly-nuclear aromatics and complex polyunsaturates enables them to pass rigorous applicable governmental and regulatory anti-pollution requirements such as those contained in the US Environmental Protection Agency National Pollutant Discharge Elimination System Permitting Program, 40 CFR Part 405-471.

Dimer acids of the single carbon chain length containing mono-unsaturated triglycerides are converted in the conventional catalytic hydrodeoxygenation and isomerization to a mixture of isoparaffins. The reactor preferably consists of separate dimerization, hydrogenation, hydrodeoxygenation and isomerization stages. The severity of the hydroprocessing step is controlled to minimize cracking of the dimer acids and to cause the desired degree of isomerization of the product. The severity of the hydroprocessing isomerization is limited such that substantially only monomethyl isomers are produced. The isoparaffin component is blended in a controlled proportion with one or more other component isoparaffins having different average molecular weights that are prepared from one or more other genetically modified seed crops in the same manner as described above. A portion of the dimer acids from the processing plant is supplied to the reactor in which a portion of such supplied C20 or C22 FFA based dimer acids are subjected to the mild multi step Hydroprocessing sequence with subsequent blending of discrete product streams to control the overall chemical and physical properties of the lubricant or fuel blend stocks..

Preferably the triglycerides are first hydrogenated to maximize the monounsaturated content of the fatty acid chains before they are hydrolytically separated from the glycerol back bone. The Hydroprocessing step on the dimer acid can be performed in a single hydrodeoxygenation and isomerization reactor vessel, or the isomerization step can be performed subsequent to the hydrodeoxygenation in a separate reactor vessel.

In an alternative embodiment, the genetically modified triglycerides are heated to the minimum temperature required to cause the triglycerides molecules to decompose into bio char and the corresponding linear alpha olefin analogs of the paraffin chains. The alpha olefins are then processed by well-known linear alpha olefin oligomerization processes to produce fully synthetic bio-derived poly-alpha olefins and other olefinic oligomers that are then saturated by treatment with hydrogen to produce star-shaped isoparaffins for use in SD”s, jet fuel blend stocks, or other petrochemical products, isoparaffin components produced by the above-described TGFA hydroprocessing process can be mixed with isoparaffin components produced by the oligomerization process to produce synthetic fluids having different desired properties.

The process of the invention enables the producer to avoid entirely the need to use petroleum based feeds in the production of lubricant base stocks, distillate and jet fuel blend stocks, and, with the genetically engineered feeds to control the overall hydrocarbon distribution in the final product. This allows the ultimate chemical and physical properties of the product to be precisely controlled via the crop production chemistry rather than trying to do so via substantially more difficult to control hydroprocessing and oligomerization chemistry.

Castor Based Process Configuration

Castor bean crops used to produce novel synthetic fluids of the invention are genetically selected or modified in such a way that the fatty acids in the triglycerides of the seeds are predominantly of a specific carbon chain length, preferably C14, C16 monounsaturated hydrocarbon backbones and/or in the case of the Cl 8 FFA, an allylic alcohol structure such as that in Ricinoleic acid. In a preferred embodiment of the method of invention, the seed crop used to produce the triglycerides matures rapidly and can be interspersed with the successive plantings of another crop, such as a food crop. Genetically selected or modified castor is a rapidly growing seed crop that can be an excellent source of triglycerides in the desired carbon chain lengths. Advantageously, it can be produced in rotation with traditional food crops, such as wheat or soy or cotton, to maximize the CO2 consumption rate of a given acre of land. The cellulosic material that remains after the TGF”s in the seeds are isolated from the crop can be gasified to produce syngas to supply hydrogen for later hydroprocessing steps, or it can be converted into a specific high purity biochar for use in soil amendments. Soy mash, after treatment is used directly for animal feed

Genetically selected or modified castor is a particularly preferred seed crop for use in the present invention because they go from planting of the seeds to harvest within 90 days, requires minimal water, and do well in semi-arid soils, and it provides a feedstock high in C14:l, 16: 1 or 18:1-OH FFA moieties. Also, the residual cellulosic material can be used as a component for biofertilizer or as an animal fodder. Genetically modified strains of castor have been reported in US20130254913, US20140121392, US20170035012, US 20180177149 which are incorporated herein in their entirety for all purposes.

The C14:l and Cl 6: 1 FFA’s or their corresponding alkyl esters can be used to produce the corresponding dimers - which can then be used as feedstock for the bio-base stock production process. In the case of Ricinoleic acid feedstocks, they can first be dehydrated by know methods and the corresponding di -unsaturated analogs subjected to selective hydrogenation to produce mono-unsaturated FFA’s or their corresponding alkyl esters. The method of the invention is especially advantageous from environmental point of view because it is capable of achieving a net negative greenhouse gas footprint. The extent to which it is negative will depend on the specific seed crop used, the amount of fertilizer and water needed to grow the crop, and the impact on the land being used versus what it was being used for before the seed crop was planted.

The genetic modification of the seed crops such castor to generate specific single carbon chain length (or combinations thereof) fatty acids may be performed by any method known to those skilled in the art. Techniques capable of performing such genetic modifications are disclosed e.g., in international applications WO/2009/125401, WO/2009/109054, WO/2009/147127 or WO/2009/129582, and in US Patent Applications US20180177149, US20140121392 and US20130254913, the disclosures of which are hereby incorporated by reference in their entirety for all purposes.

In one illustrative procedure, the fatty acids are cleaved using a thermochemical process in which the triglycerides or heated in an aqueous acidic solution or an aqueous basic solution, preferably in the presence of a catalyst. One such thermochemical process for cleaving fatty acids from a glycerol backbone is described in Myllyoja et al, U.S. patent application Ser. No. 11/477,922 which is hereby incorporated by reference in its entirety for all purposes. In one embodiment (of our invention, the cleavage process step involves a decarboxylation reaction as described in Myllyoja.

Alternatively, the process may comprise the disassembly of a medium chain fatty acid source from glycerol by decarboxylation of the fatty acid chains while still attached to the glycerol backbone, thus simultaneously cleaving the fatty acid group and producing glycerol and one or more hydrocarbon products. In such case, the hydrocarbon product will be one carbon shorter in chain length than the original fatty acid.

In another embodiment, the fatty acid chains may be partially reduced while still attached to the glycerol backbone, thereby producing glycerol and the hydrocarbon product, in such case, the hydrocarbon product, prior to isomerization, has the same carbon chain length as the original fatty acid coupled to the triglycerides. The reduction is preferably performed in the presence of hydrogen and any suitable catalyst. In an additional embodiment, the Triglycerides may be disassembled by chemical reduction of the glycerol backbone, thereby producing the hydrocarbons and propane, propanol, propanediol or other glycerol-derived products or combinations thereof.

Alternatively, fatty acids may be cleaved from the glycerol by an enzymatic process such as the process described in U.S. Pat. No. 4,394,445, herein incorporated by reference in its entirety for all purposes, or other biological processes known in the art. Examples of enzymes that may be used include, without limitation, esterases, lipases, proteases, or combinations thereof. As used herein, a "biological process” is any process utilizing biological organisms (e.g. bacteria, algae, etc.) to accomplish the desired reaction. In another embodiment, the fatty acids may be cleaved from the glycerol backbone by acid-catalyzed hydrolysis of the glycerides in the triglycerides.

After cleavage of the fatty acids from the glycerol, the glycerol may be separated from the fatty acids. The separation may be accomplished by various conventional methods including, without limitation, liquid-liquid extraction, supercritical solvent extraction, distillation, membrane filtration, acidulation, centrifugation, by gravity separation, or combinations thereof. Once separated from the fatty acids, the separated glycerol may be used for further reforming or other purposes.

If the end product is to be an automotive lubricant base stock, the Triglycerides may be Isolated separately from each genetically modified or selected seed crop, are dimerized and then Hydroprocessed to hydrodeoxygenate and isomerize each dimer acid to generate corresponding component isoparaffins, substantially all of the molecules of each component isoparaffin containing the same number of carbon atoms, preferably between C14, C16 and/or C18 of the original monomer used to produce the dimer acid. Isoparaffin components containing different single numbers of carbon atoms are mixed in controlled proportions to form a base stock with controlled viscomertric and vapor pressure. In accordance with the method of the invention, the severity of the isomerization hydrotreatment of each component is controlled such that the degree of cracking is minimized and the isomers generated are primarily monomethyl branched isomers. Especially in the case where the end product is to be a lubricant base stock, it is desirable that at least 30% of the base stock molecules have odd carbon numbers. This is achieved in our HDO and Selective Hydrocracking steps where the feed dimer of even carbon number is subjected to a hydrocracking or hydrogenolysis reaction to break off one or a combination of Cl, C2, C3 or C4 light hydrocarbons such that an odd number of carbons remain.

The conversion of the TGFA's may be performed in the presence of the catalyst at temperatures from about 250. degree. C. to about 375. degree. C., preferably about 340. degree. C. to about 370. degree. C., but more preferably about 350. degree. C. The conversion of the TGFA's is preferably performed in the presence of hydrogen, preferably at a gauge pressure ranging from about 75 psig to about 750 psig, preferably ranging from about 350 psig to about 650 psig, more preferably from about 450 psig to about 550 psig. The catalyst is most preferably prepared for usage by pretreatment with a sulfiding agent and hydrogen, resulting in the formation of the active metal sulfide.

In general, the isomerization hydrotreatment for each component should be the minimum required to obtain the required low temperature properties, e.g., a freeze point of less than - 47. degree. C. in practice, the appropriate degree of hydrotreatment and isomerization for the components of the synthetic fluids of the invention depends on the carbon chain length of the fatty acid and can be determined by simple experimentation. For instance, a series of tests could be run for a given component using different severities of hydrotreatment and the hydrocarbon product produced by each test run would be tested to identify the minimum hydrotreatment conditions that achieve the required freeze point. The optimum conditions will vary from feed to feed, e.g., with the specific carbon chain length of the fatty acid in the TGF”s, and from catalyst to catalyst.

A chemiometric study would then be performed in which the components are mixed in different proportions to determine the optimal mixture or range of mixtures that meet the requirements of the applicable specifications, e.g., ASTM 7566, such as viscometric properties, cloud point and thermal and oxidative stability. Once those conditions are determined, they would be used in the normal production run to generate large scale batches of product. This method provides a self- defining approach that maximizes performance for any combination of the variables significant to a given application. The fact that, in accordance with the invention, substantially all of the fatty acids in the TGFA's of a particular feed have the same carbon chain length allows the determination of an optimal set of processing conditions for a given feed that results in a much more precisely controlled product composition than would be possible with a feed containing fatty acids of varying carbon chain lengths.

The novel synthetic fluids produced by the method of the invention are biodegradable, due to the controlled degree of cyclization and aromatization, under the conditions of production, are nontoxic and fully renewable, and do not require any petroleum based components to function as lubricant base stocks, thereby substantially reducing the overall GHG footprint of the production and use of the synthetic fluids produced by the method of the invention.

The novel synthetic lubricant fluids of the invention consist essentially of controlled mixtures of preferably C28-C36 hydrocarbons, in which the molecules have controlled degrees of branching, and a minimized content of shorter chain molecules resulting from cracking during hydroprocessing. The processing condition for the isoparaffin components of the fluids are preferably controlled such that each of the components, and therefore the blended fluid, is substantially free of poly-nuclear aromatics and complex polyunsaturates. The controlled relative amounts of C14-C16 molecules in the synthetic fluids of the invention result in fluids having optimal combinations of properties for a given application such as lubricant base stocks. The fact that the fluid is substantially free of poly-nuclear aromatics and complex polyunsaturates enables them to pass rigorous applicable governmental and regulatory anti-pollution requirements such as those contained in the US Environmental Protection Agency National Pollutant Discharge Elimination System Permitting Program, 40 CFR Part 405-471.

Lubricant Formulations

The hydrocarbon mixtures disclosed herein can be used as lubricant base stocks to formulate final lubricant products that also include additives. In certain variations, a base stock prepared according to the methods described herein is blended with one or more additional base stocks, e.g., one or more commercially available PAOs, a Gas to Liquid (GTL) base stock, one or more mineral base stocks, a vegetable oil ester or estolide base stock, an algae-derived base stock, a second base stock as described herein, or any other type of renewable base stock. Any effective amount of additional base stock may be added to reach a blended base oil having desired properties. For example, blended base oils can comprise a ratio of a first base stock as described herein to a second base stock (e.g., a commercially available base oil PAO, a GTL base stock, one or more mineral base stocks, a vegetable oil base stock, an algae derived base stock, a second base stock as described herein) that is about is from about 1-99%, from about 1-80%, from about 1-70%, from about 1-60%, from about 1-50%, from about 1-40%, from about 1-30%, from about 1-20%, or from about 1-10%, based on the total weight of the composition may be made.

Also disclosed herein are lubricant compositions comprising a hydrocarbon mixture described herein. In some variations, the lubricant compositions comprise a base oil comprising at least a portion of a hydrocarbon mixture produced by any of the methods described herein, and one or more additives selected from the group of antioxidants, viscosity modifiers, pour point depressants, foam inhibitors, detergents, dispersants, dyes, markers, rust inhibitors or other corrosion inhibitors, emulsifiers, de-emulsifiers, flame retardants, antiwear agents, friction modifiers, thermal stability improvers, multifunctional additives (e.g., an additive that functions as both an antioxidant and a dispersant) or any combination thereof. Lubricant compositions may comprise hydrocarbon mixtures described herein and any lubricant additive, combination of lubricant additives, or available additive package.

Any of the compositions described herein that are used as a base stock may be present at greater than about 1% based on the total weight of a finished lubricant composition. In certain embodiments, the amount of the base stock in the formulation is greater than about 2, 5, 15 or 20 wt % based on the total weight of the formulation. In some embodiments, the amount of the base oil in the composition is from about 1-99%, from about 1-80%, from about 1-70%, from about 1- 60%, from about 1-50%, from about 1-40%, from about 1-30%, from about 1-20%, or from about 1-10% based on the total weight of the composition. In certain embodiments, the amount of base stock in formulations provided herein is about 1%, 5%, 7%, 10%, 13%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 99% based on total weight of the formulation. As is known in the art, types and amounts of lubricant additives are selected in combination with a base oil so that the finished lubricant composition meets certain industry standards or specifications for specific applications. In general, the concentration of each of the additives in the composition, when used, may range from about 0.001 wt. % to about 20 wt. %, from about 0.01 wt. % to about 10 wt. %, from about 0.1 wt. % to about 5 wt. % or from about 0.1 wt. % to about 2.5 wt. %, based on the total weight of the composition. Further, the total amount of the additives in the composition may range from about 0.001 wt. % to about 50 wt. %, from about 0.01 wt % to about 40 wt %, from about 0.01 wt % to about 30 wt %, from about 0.01 wt. % to about 20 wt. %), from about 0.1 wt. % to about 10 wt. %, or from about 0.1 wt. % to about 5 wt. %, based on the total weight of the composition.

In some variations, the base oils described herein are formulated in lubricant compositions for use as two cycle engine oils, as transmission oils, as hydraulic fluids, as compressor oils, as turbine oils and greases, as automotive engine oils, as gear oils, as marine lubricants, and as process oils. Process oils applications include but are not limited to: rolling mill oils, coning oils, plasticizers, spindle oils, polymeric processing, release agents, coatings, adhesives, sealants, polish and wax blends, drawing oils, and stamping oils, rubber compounding, pharmaceutical process aids, personal care products, and inks.

In yet other variations, the base oils described herein are formulated as industrial oil or grease formulations comprising at least one additive selected from anti-oxidants, anti-wear agents, extreme pressure agents, defoamants, detergent/dispersant, rust and corrosion inhibitors, thickeners, tackifiers, and demulsifiers. It is also contemplated that the base stocks of the invention may be formulated as dielectric heat transfer fluids composed of relatively pure blends of compounds selected from aromatic hydrocarbons, polyalphaolefins, polyol esters, and natural vegetable oils, along with additives to improve pour point, increase stability and reduce oxidation rate.

Dimer acids of the single carbon chain length containing mono-unsaturated TGFA's are converted in the conventional catalytic hydrodeoxygenation and isomerization to a mixture of isoparaffins. The reactor preferably consists of separate dimerization, hydrogenation, hydrodeoxygenation and isomerization stages. The severity of the hydroprocessing step is controlled to minimize cracking of the dimer acids and to cause the desired degree of isomerization of the product. The severity of the hydroprocessing isomerization is limited such that substantially only monomethyl isomers are produced. The isoparaffin component is blended in a controlled proportion with one or more other component isoparaffins having different average molecular weights that are prepared from one or more other genetically modified seed crops in the same manner as described above. A portion of the dimer acids from the processing plant is supplied to the reactor in which a portion of such supplied C14 or C16 FFA based dimer acids are subjected to the mild multi-step Hydroprocessing sequence with subsequent blending of discrete product streams to control the overall chemical and physical properties of the lubricant or fuel blend stocks..

Preferably the TGFA's are first hydrogenated to maximize the monounsaturated content of the fatty acid chains before they are hydrolytically separated from the glycerol back bone. The Hydroprocessing step on the dimer acid can be performed in a single hydrodeoxygenation and isomerization reactor vessel, or the isomerization step can be performed subsequent to the hydrodeoxygenation in a separate reactor vessel.

In an alternative embodiment, the genetically modified TGFA's are heated to the minimum temperature required to cause the TGFA's molecules to decompose into bio char and the corresponding linear alpha olefin analogs of the paraffin chains. The alpha olefins are then processed by well-known linear alpha olefin oligomerization processes to produce fully synthetic bio-derived poly-alpha olefins and other olefinic oligomers that are then saturated by treatment with hydrogen to produce star-shaped isoparaffins for use in SDF's, in synthetic drilling fluids, jet fuel blend stocks, or other petrochemical products. Isoparaffin components produced by the above-described TGFA hydroprocessing process can be mixed with isoparaffin components produced by the oligomerization process to produce synthetic fluids having different desired properties.

The process of the invention enables the producer to avoid entirely the need to use petroleum based feeds in the production of lubricant base stocks, and, with the genetically engineered feeds to control the overall hydrocarbon distribution in the final product. This allows the ultimate chemical and physical properties of the product to be precisely controlled via the crop production chemistry rather than trying to do so via substantially more difficult to control hydroprocessing and oligomerization chemistry.