PREPARATION AND APPLICATION THEREOF

TECHNICAL FIELD: The present disclosure relates generally to the field of petroleum science. In particular, the present invention is related to the non-halogenated heavy naphtha reforming catalyst development. The invention further provides a process of synthesizing the same and uses thereof.

BACKGROUND ART:

Bifunctional catalysts based on metal (oxides, sulfides) in combination with zeolites find application in large-scale hydro-isomerization and hydro-cracking processes in oil refineries for the production of transportation fuels and chemicals. Besides industrial use, they are also studied for the conversion of biomass feedstocks, waste plastics and for the hydrogenation of CO or CO2 towards lower olefins (C2-C4), light alkanes and aromatics. The bifunctional catalysts employed for the conversion of hydrocarbons, consist of a (de)hydrogenation function and Bronsted and Lewis acid functions. The (de)hydrogenation function can be performed by highly active noble metals like platinum or palladium, or more abundant, less active metal (sulfides), such as nickel, nickel-molybdenum sulfide or cobalt-molybdenum sulfide. The acid function, responsible for alkene protonation and subsequent isomerization and/or cracking, is commonly obtained by using an halogenated alumina, a zeolite, an amorphous silica-alumina support or other solid acid supports.

Motor spirit (MS) is one of the important products of crude oil refining and research octane number (RON) specifies the anti-knocking properties of the fuel. Naphtha from atmospheric distillation column in the refinery needs to be upgraded to meet the market specifications of the MS, where heavy naphtha reforming is one such upgradation processes to improve RON and aromatic contents of the naphtha product. Based on the market needs, the upgraded heavy naphtha is usually blended with other naphtha product streams to make MS of required specifications. The catalyst involved in naphtha reforming is a bi-functional metal-acid catalyst, where the metal is usually a noble metal and the acidity is achieved from chlorinated alumina support. The metal catalyzes desirable dehydrogenation reactions to produce aromatics, whereas acidic centers are responsible for isomerization product. Both metal and acid centers involve in desirable reactions such as dehydrocylization to convert n-paraffins to aromatics. The molecular transformations or reactions involved in the catalytic reforming finally improve the quality of the reformate product with improved RON and aromatics. Balancing the acid and metal centers is key in designing a bi-functional catalyst to minimize undesirable reactions such as cracking and to improve the reformate yields.

Continuous use of Chlorine (Cl) in heavy naphtha reforming units demand operating Cl guard beds in the downstream units, which add to the operating cost of the refinery. Also, corrosion of downstream units, due to Cl is inevitable. Even if some % of N compounds are present in the feed, formation of solid ammonium chloride is unavoidable, which can cause congealing of downstream units.

To provide a safer alternative, the present invention provides an efficient catalyst which comprises halogen free solid acid support. Further, the present invention also provides a method of synthesizing said catalyst and uses thereof.

SUMMARY OF THE INVENTION:

The present invention relates to a catalyst comprising a halogen free solid acid support, a noble metal, a first promoter atom, and a second promoter atom. The catalyst of the present invention is a multimetallic and a heavy naphtha reforming catalyst. This catalyst differs from the conventional catalyst as it does not contain chlorine which has been proved to be corrosive and associated with some disadvantages like, formation of solid ammonium chloride in the downstream units, even if small amount of N compounds are present in the feed, operating and maintenance costs associated with the chlorine guard beds in the downstream units. Further, the present invention provides process of synthesizing the catalyst of the present invention and uses thereof. DETAILED DESCRIPTION:

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the figures and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

The terminology and structure employed herein is for describing, teaching and illuminating some embodiments and their specific features and elements and does not limit, restrict or reduce the spirit and scope of the invention.

Aspects and embodiments of the present invention will be described below in detail.

As an aspect, the present invention provides a catalyst comprising: a) a halogen free solid acid support; b) a noble metal; c) a first promoter atom; d) a second promoter atom; and e) a peptizing agent wherein said catalyst is a multimetallic and a heavy naphtha reforming catalyst.

In another embodiment, said halogen free solid acid support comprises: a) a non-acidic support; b) a first zeolite; c) a second zeolite; and d) a binder.

In yet another embodiment, said non-acidic support is selected from group consisting of Aluminium oxide (AI2O3 ) , Silicon dioxide (S1O2), Titania, Zirconia, zinc oxide, and spinel structures such as Magnesium aluminate (MgAk04), Hercynite (FeAk04). In a further embodiment, said non-acidic support is g phase of AI2O3.

In one more embodiment, the first and second zeolites are selected from group consisting of TS1, GaZSM5, ZSM-5, ZSM-11, ZSM-12, ZSM-20, X-zeolite, Y-zeolite, L-zeolite, mordemte, beta, MCM-22, and Boron containing large pore zeolites.

In one embodiment, said first zeolite is beta zeolite and second zeolite is TS1 zeolite.

In another embodiment, said binder is Boehmite, pseudoboehmite, S1O2 or AI2O3, and preferably pseudoboehmite.

In one more embodiment, said noble metal is selected from the group consisting of active metals and transitional metals.

In an embodiment, said active metals are Platinum (Pt), Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Osmium (Os) or Iridium (Ir), and preferably Pt.

In yet another embodiment, said first and second promotor atoms are selected from the group consisting of Tin (Sn), Rhenium (Re), Germanium (Ge), Iridium (Ir), Indium (In), Thallium (Tl), Lead (Pb), and Gallium (Ga).

In a further embodiment, said first promoter is Ga and the second promoter is Sn.

In one more embodiment, said peptizing agent is selected from group consisting of acetic acid in a weight percentage range of 1 - 20% (w/w) and nitric acid (HNO3) is concentration range of 0.2 - 2.0 M.

In an embodiment, said halogen free solid acid support is in a weight percentage range of 90- 98.5 % (w/w), preferably 96-98%(w/w); the noble metal is in the weight percentage range of 0.01 to 2.0%(w/w), preferably 0.1 - 1.0% (w/w); the first promoter is in the weight percentage range of 0.01 to 2.0%(w/w), preferably 0.5 - 1.5% (w/w) and the second promoter atom is in the weight percentage range of 0.01 to 2.0%(w/w), preferably 0.1 - 1.0% (w/w).

In another embodiment said non-acidic support is in the weight percentage range of 60 to 98% (w/w), preferably 95% (w/w); the first zeolite is in the weight percentage range of 1 to 40% (w/w), preferably 2% (w/w); the second zeolite is in the weight percentage range of 1 to 40 %(w/w), preferably 3% (w/w); the binder is in the weight percentage range of 1 to 20 %(w/w), preferably 10% (w/w) .

In a second aspect, the present invention provides a process of synthesizing the catalyst as claimed in claims 1-16, wherein said process comprises the steps of:

Step 1- a) carrying out exchange of protons of zeolite beta with ammonium acetate solution at 90 °C for 3 hrs; b) drying said solution of (a) at 90 °C for 8 hrs; c) adding aqueous solution of Pt(NH3)4(NC )2 to ammonia beta zeolite obtained from steps (a)-(b) for exchange for 3 hrs, followed by drying said solution at 90 °C for 8 hrs to result in Pt exchanged zeolite beta;

Step 2- d) impregnating TS1 zeolite with aqueous solution of Ga(NC )3 to obtain 1 wt% of Ga in the zeolite, then drying this impregnated TS1 zeolite 120 °C for 8hrs and calcinating at 500 °C for 4 hrs;

Step 3- e) mixing zeolites obtained from steps 1 and 2 with y-AkC and 10% pseudoboehmite to achieve final support composition of 95% y-AhC and 2 % zeolite beta and 3%

TS1 zeolite. f) extrudating the support obtained from steps (a) to (e) using 0.75M HNC as peptizing agent; drying it at 120 °C for 8hrs and calcinating at 500 °C for 4 hrs for further processing; Step 4 - g) impregnating aqueous solution of Sn (SnCh.2H2C)) and Pt (HzPtC eHzO) on the composite support prepared in step-3; h) drying said catalyst at 120 °C for 8hrs and calcinating the same at 500 °C for 4 hrs to obtain the desired catalyst. In an embodiment, said impregnation of Ga, Sn and Pt is done by wet, incipient or spray impregnation, preferably by wet impregnation. In yet another embodiment, said Sn and Pt is impregnated either sequentially or incorporated by co-impregnation on to the composite.

In a third aspect, the present invention provides use of the catalyst of the present invention in the conversion of low octane crude oil into high-octane liquid products called reformates, which are further used as blending stocks for high-octane gasoline.

EXAMPLES:

Example 1: Step wise preparation of catalyst of the present invention. Materials used: Procedure:

The procedure discussed above is the best method identified out of ~ 70 reactions carried out from catalysts developed in-house. Details of other alternative methods for some of the above steps are mentioned below. Alternatives to Steps 2:

• Incipient impregnation or spray impregnation of Ga as alternative to wet impregnation.

Alternatives to Step 4:

• Co-impregnation of Sn and Pt as alternative to sequential impregnation.

• Incipient impregnation or spray impregnation of Sn and Pt as alternative to wet impregnation.

Example 2: Demonstrating activity of the catalyst of the present invention.

The developed formulations have been tested at 2gm scale in a fixed bed reactor, where heavy naphtha has been used as feed and catalyst reduction and reactions are carried out under the following conditions:

Briefly, the catalyst is placed in middle of the reactor, where constant heating zone is ensured throughout the reaction. The reactor is made up of SS316 with ID of 10 mm. SiC has been used as inert material to fill both sides of the catalyst bed in the reactor. Mass balance of the reaction is carried out by quantifying the gas and reformate samples collected at different intervals. The analysis of liquid and gas samples are carried out by GC-PIONA and RGA respectively.

Example 3: Discussing what happens if there is no zeolite in the catalyst or a different zeolite combination is used.

Table 1 below compares activity of the catalyst of the present invention with catalysts either having no or different zeolites and those containing chlorine. For the lab scale studies, it is desirable for an ideal catalyst that it converts maximum amount of naphthenes and other hydrocarbon into aromatics, with a reformate yield between 80-90% and benzene concentration < 2%. As it is evident from the Table 1 that catalyst without zeolite - only AI2O3 has poor conversion of naphthenes and other hydrocarbon into aromatics i.e. amount of Naphthenes, i-Par, n-Par remains nearly unchanged and aromatics obtained are only 49.13% in amount. Further, it has been shown that use of ZSM zeolite and AI2O3 composite though show good conversion of Naphthenes, i-Par, n-Par to aromatics, however it has very high level of benzene i.e. 11.5% and quite low reformate yield i.e. 40%. Furthermore, use of Mordenite zeolite and AI2O3 composite again include decent conversion however provides an un-satisfying level of benzene and reformate yield. Again, use of 10% of beta and 90% of AI2O3, and with only Pt and Sn, shows better conversion and reformate yield however since the level of Benzene i.e. 3.75% is still not within the desirable range of <2%, the inventor tested the catalyst with only 2% beta and 98% AI2O3 and with only Pt and Sn and noted that whilst level of benzene and reformate yield are in the desirable range, the level of conversion from Naphthenes, i-Par, n-Par to aromatics have decreased i.e. for earlier catalyst the aromatic cone was 92.3% and for this catalyst the aromatic cone is 79.36%. The inventors also provide data with zeolites used in present invention, it is shown that said catalyst has desirable reformate yield i.e. 82%, good conversion as the aromatic cone is 89.42% and low level of benzene i.e. 2.10%. This is comparable to the chlorinated catalyst (commonly used industrial catalyst) as shown in last row of the table. Table 1:

F

W t out zeo te -

23.48 10.74 12.67 3.97 49.13 90.5 91 0.45 Only AI2O3

Use of ZSM zeolite and A1203 1.26 0.94 0.67 0.12 97 106.4 40 11.5 composite

Use of Mordenite zeolite and A1203 5.4 3.53 1.68 0.15 89.13 104.2 38 9.91 composite

Use of 10% of beta and 90% of A1203,

0.85 3.59 2.85 0.42 92.3 105.9 70 3.75 and with only Pt and Sn

Use of only 2% beta and 98% A1203 and 2.1 10.49 6.41 1.61 79.36 102.8 82 1.0 with only Pt and Sn

With zeolites used

0.66 5.40 3.56 0.93 89.42 106.0 82 2.10 in present inv i

Chlorinated catalyst (commonly

0.49 6.79 3.09 0.68 88.66 104.5 84 1.54 used industrial catalyst)

• Except RON, all other amounts are in units of wt%. RON does not carry any units.

5 It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the constructions set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense. The invention has been described with reference to preferred and alternate embodiments. Modifications and alterations will become apparent to those skilled in the art upon reading and understanding the detailed discussion of the invention provided herein. This invention is intended to include all such modifications and alterations insofar as they come within the scope of the present invention. These and other modifications of the preferred embodiments as well as other embodiments of the invention will be obvious from the disclosure herein, whereby the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

Finally, to the extent necessary to understand or complete the disclosure of the present invention, all publications, patents, and patent applications mentioned herein are expressly incorporated by reference therein to the same extent as though each were individually so incorporated.