CANNABIS PLANT MATERIAL

1. TECHNICAL FIELD

The invention relates to an apparatus, system and method for the processing of harvested cannabis plant material. The invention has particular application to the extraction of target compounds of cannabinoids, such as cannabidiol or tetrahydrocannabinol and varian analogues, from freshly harvested cannabis.

2. BACKGROUND

Cannabis, primarily cannabis sativa but also Cannabis indica and Cannabis ruderalis, for medicinal purposes such as pain relief, is legally recognised in many countries, including the United States and New Zealand. It can be provided to the consumer as a dried product (leaves or flowers) or as a dosage in a conventional pharmaceutical form, such as a pill, tablet, or as an oil/liquid for oral consumption. There is also an increasing need to separate specific compounds, in certain forms, from cannabis plant material for use in medicaments for treatment of specific health conditions.

Consequently cannabis plants are being cultivated on an increasing scale to meet demand. However, cultivating cannabis plants on a commercial scale has a number of issues, due to space constraints, availability of resources, and technological inefficiencies. This means the cost of purchasing medicinal cannabis can be significant, a reflection of the expense involved in growing, processing and extracting from the cannabis plant the valuable components, the cannabinoids, such as cannabidiol (CBD), tetrahydrocannabinol (THC), or varian analogues thereof, into a form that is vendible to the consumer.

This expense can make it difficult for persons requiring medicinal cannabis to access the product. It can also make it prohibitively expensive for potential cannabis farmers to enter the market, which in turn keeps the price of cannabinoid containing medicines high. To optimise growth of the cannabis plant, they are often grown indoors and most growers supplying medicinal cannabis to the market take this approach. This allows the grower to better control the temperature, light conditions, and security of the plant crop. A drawback to growing cannabis plants indoors is that a major amount of infrastructure is required, from growing space, i.e. buildings, to electrical equipment and watering paraphernalia.

Once harvested, the cannabis plant material degrades relatively quickly and is vulnerable to mould and pestilent insects. The harvested cannabis plant material also has a significant moisture content, which can be as much as 70% and contributes to its undesirable breakdown. This moisture needs to be eliminated or at the very least significantly reduced before the plant material can be further processed. The drying step is both labour and energy demanding, as the plants need to be trimmed and stored in a relatively dehumidified environment for drying for up to two to three weeks.

Harvesting of the cannabis plants usually involves removal of a major proportion of their biomass, the stems and fan leaves, leaving only the sugar leaves and flowers. These contain the valuable component of interest, a structure known as a trichome, a bulbous resinous gland on a thin stem. It is the trichomes which contain the target compounds, cannabinoids such as CBD and THC, that need to be extracted with further processing.

A common commercial approach to extracting target compounds/value components from cannabis plant material involves a multi-stage process. First, the moisture level in the plant matter containing the trichomes is reduced to only around 10% of the overall biomass of the plant matter. The cannabinoids of value can then be extracted, which usually entails the application of solvents, such as ethanol, to the trichomes. However, this requires the use of complex scientific equipment, with skilled staff being necessary to operate the processing machinery and who need to be remunerated appropriately. The solvents used in the processing can be hazardous and must be stored in safe, secure environments and also disposed of appropriately. Another approach to separating out the trichomes from the plant matter involves immersing it in a tank of cool or chilled water and gently agitating the resulting mixture. This separates the trichomes from the rest of the plant matter and they can then be captured and extracted from the water using a separator. An example of such an arrangement is disclosed in PCT Application No. PCT/CA2018/051197. However, a drawback to this arrangement is that it can be very wasteful of water, particularly on a commercial scale, as it typically requires 20 parts of water to one part plant matter for optimum operation. After the separation of the trichomes from the water, it is then discarded as waste. Furthermore, the separation of the trichomes from the plant matter can also be relatively prolonged and time inefficient.

As will be appreciated there is considerable capital and operational expense in growing and processing cannabis plants for the purpose of supplying medicinal cannabis. Together with the time and processing inefficiencies of existing extraction processes, this has a bearing on the retail price for the end product. In some markets, this may mean medicinal cannabis or medicines containing cannabinoids may be financially inaccessible to at least some of those individuals who need it for treatment of health problems and/or pain relief.

A solution to the aforementioned problems is desired.

3. BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing an apparatus, system and method for the cost- effective extraction of compounds of interest, i.e. value components, from freshly harvested cannabis plant material. These compounds of interest include, but are not limited to, CBD, THC and varian analogues thereof.

In particular, the present technology provides an apparatus, system and method for the removal of value components of the cannabis plant material, the trichomes. These are the parts of the plant that are particularly high in CBD and THC compounds at certain stages of the life of the plant. According to one aspect of the present technology, there is a provided a method of separating trichomes from harvested cannabis plant material, wherein the method includes the steps of: a) charging a vessel with a quantity of harvested cannabis plant material and a quantity of a cooling agent to create a first mixture; b) filtering the first mixture in the vessel to produce a first laden quantity of cooling agent containing a first filtrate including at least some trichomes; c) withdrawing the first laden quantity of cooling agent containing the first filtrate from the vessel and transferring to a separator; d) operating the separator to remove at least a portion of the trichomes from the first filtrate of the first laden quantity of cooling agent; e) returning the first laden quantity of cooling agent to the vessel and adding a further quantity of harvested cannabis to create a second mixture; f) filtering the second mixture in the vessel to produce a second laden quantity of cooling agent containing a second filtrate including at least some trichomes; g) withdrawing the second laden quantity of cooling agent containing the second filtrate from the vessel and transferring to the separator; h) operating the separator to remove at least a portion of trichomes from the second filtrate of the second laden quantity of cooling agent.

Preferably, during steps c) and g), the first and second laden quantities of cooling agent containing the first and second filtrates respectively are passed through a pump to agitate same prior to being introduced to the separator.

Alternatively, or additionally, during steps b) and f), the first and second mixtures are vigorously agitated while being filtered to produce the first and second laden quantities of cooling agent that contain the first and second filtrates respectively. Alternatively, or additionally, during steps c) and g), the first and second laden quantities of cooling agent containing the first and second filtrates respectively are passed through a static mixer and a first portion of same is returned to the vessel and a second portion of same is introduced to the separator.

Preferably, at least 20% to 70% of the first and second laden quantity of cooling agent is returned to the vessel after passing through the static mixer, with the balance proceeding to a scrape surface filter and/or the separator.

Alternatively, during steps c) and g), the first and second laden quantity of cooling agent is passed through a scrape surface filter and a first portion of same is diverted back to the vessel and a second portion of same is introduced to the separator.

Preferably, at least 20% to 70% of the first and second laden quantity of cooling agent comprising the first portion of same is returned to the vessel after passing through the scape surface mixer, with the second portion being the balance proceeding to the separator.

Preferably, of the portion of the first and second laden quantity of cooling agent reaching the separator, at least 30% to 80% of the first and second laden quantity of cooling agent is returned to the vessel after passing through the separator, the balance being collected and transferred for further processing. It will be understood that at least part of the balance includes at least a portion of the filtrate, which contains some trichomes.

Preferably, during step e), the cooling agent is chilled before being returned to the vessel.

Preferably, the cooling agent is a slurry of ice and water. Alternatively, the cooling agent is chilled water.

Preferably the cooling agent is chilled to a temperature of between 0° Celsius to 5° Celsius. Even more preferably, the cooling agent is chilled to a temperature substantially at or close to 0° Celsius.

Preferably, the ratio of cooling agent to harvested cannabis plant material is from between 0.5:1 to

10:1. Even more preferably, the ratio of cooling agent to harvested cannabis plant material is between 1:1 to 5:1. In a particularly preferred embodiment, the ratio of cooling agent to harvested cannabis plant material is approximately 2:1.

Preferably, prior to step a), the harvested cannabis plant material undergoes a pre-processing step where the stalks and/or fan leaves are substantially removed or reduced in size through the use of a mill, cutting blades or the like.

According to one aspect of the present technology, there is provided a system for use in the method of separating trichomes from harvested cannabis plant material substantially as described above, wherein the system includes: a separator; a vessel arranged to receive harvest cannabis plant material, wherein the vessel is provided with: a charger for a cooling agent; a filtering medium arranged to extract a filtrate from a mixture of harvested cannabis plant material and cooling agent; an outlet, wherein the outlet is communicative with the separator and arranged to transfer a quantity of filtrate to the separator; and one or more recirculation loops configured to, in use, return at least a portion of the filtrate from the separator to the vessel.

Preferably, the vessel is an open tank. Even more preferably, the vessel is a substantially cylindrical open tank.

Preferably, the tank has a continuous side wall and a base.

Preferably, the outlet of the tank is at or proximate the base. Preferably, the tank includes a charger for the harvested cannabis plant material to be introduced to the tank.

Preferably, the filtering medium is a substantially cylindrical basket.

Preferably, the dimensions of the cylindrical basket are 80% to 95% of the dimensions of the tank.

Preferably, the cylindrical basket includes a continuous side wall with a plurality of perforations. Even more preferably, the continuous side wall is fabricated as a mesh.

Alternatively, the filtering medium is a screen at or proximate the outlet of the tank.

Preferably, the tank includes an agitator. Even more preferably, the agitator is arranged to vigorously agitate and mechanically work the contents of the tank when in use.

Preferably, the system includes a flow path for the filtrate extracted from the mixture of cooling agent and harvested cannabis plant material from the outlet to the separator. Even more preferably, the system includes a pipeline from the outlet to the separator.

Preferably, the system includes a pump on the pipeline between the outlet and the separator. Even more preferably, the pump is configured to agitate the filtrate prior to being introduced to the separator.

Preferably, the system includes a static mixer on the pipeline between the outlet and the separator. Even more preferably, the static mixer is configured to agitate and/or separate at least some of the filtrate prior to being introduced to the separator.

Preferably, the system includes a scrape surface filter on the pipeline between the outlet and the separator. Even more preferably, the scrape surface filter is configured to agitate and/or separate at least some of the filtrate prior to being introduced to the separator.

Preferably, the system includes a first recirculation loop, wherein the first recirculation loop is a pipeline for transferring at least some filtrate from the separator back to the vessel. Preferably, the first recirculation loop includes a cooling arrangement to bring the filtrate to a desired temperature before it is returned to the vessel.

Preferably, the system includes a second recirculation loop, wherein the second recirculation loop is a pipeline for transferring at least some filtrate from the scrape surface filter back to the vessel.

Preferably, the second circulation loop includes a cooling arrangement to bring filtrate to a desired temperature before it is returned to the vessel.

Preferably, the separator is arranged to remove at least some filtrate from the system.

Preferably, the system includes a pipeline from the separator to a processing station, wherein the pipeline is arranged to transfer at least some filtrate from the separator to the processing station.

Preferably, the processing station is arranged to perform one or more of clarification, de-watering, and/or extraction of value components from the filtrate.

4. BRIEF DESCRIPTION OF DRAWINGS

One of more embodiments of the present technology will be described below by of example only, and without intending to be limited, with reference to the following drawings, in which like reference numerals refer to similar elements including:

Figure 1 is a flow chart for the steps of processing harvested cannabis;

Figure 2 is a schematic of an example system for processing harvested cannabis in accordance with one aspect of the present technology;

Figure 3 shows a further schematic of the system of Figure 2;

Figure 4 shows a schematic of an example of a system for processing harvested cannabis in accordance with another aspect of the present technology; Figure 5 shows a schematic of the system of Figure 4 with a pathway including a first recirculation loop to the vessel of the system for processing harvested cannabis in operation;

Figure 6 shows a schematic of the system of Figure 4 with a pathway including a second recirculation loop to the vessel of the system for processing harvested cannabis in operation; and

Figure 7 shows a schematic of the system of Figure 4 with a pathway to the separator of the system for processing harvested cannabis in operation.

5. DETAILED DESCRIPTION OF EXAMPLES OF THE PRESENT TECHNOLOGY

5.1. Processing Method for Freshly Harvested Cannabis Plant Material

Embodiments of the present technology relates to methods and equipment used to process harvested cannabis.

Harvested cannabis should be understood to mean cannabis plant material that has reached an age appropriate for processing, which is typically eight to ten weeks after flowering. The cannabis plant comprises three main parts; the stalk, the leaves (fan leaves, which are the larger, sun-collecting leaves of the plant, and the sugar leaves, that form around the flower, or bud, of the plant), and the flower.

The value components of the cannabis plant are substantially contained in the trichomes. These are found primarily in the sugar leaves and the female flowers of the plant. The trichomes are not found in major quantities in the male flowers.

The colour of the trichomes may be indicative of when the plant should be harvested; if clear, there is minimal THC and/or CBD present; if somewhat translucent or cloudy, an increasing amount of THC/CBD is present. If amber, the THC/CND concentration declines. The grower will preferably harvest the cannabis plants when the THC/CBD presence in the trichomes is optimal. One method of harvesting essentially involves separating the stalk from the root structure using cutting equipment. Following harvesting, the resulting plant material goes through several steps of processing, generally indicated as arrow 1 as indicated in Figure 1: A) pre-processing; B) preconcentration; C) clarification; D) de-watering; E) extraction; and F) refining.

Each of these steps shall now be described.

5.1.1 Pre-processing

Once harvested, the cannabis plant material undergoes an initial pre-processing step A, which involves the removal of the larger, lower value/non-productive components of the plant material, such as the stalks and fan leaves. This leaves the valuable components of the plant material, the buds/flower and sugar leaves for further processing in accordance with the present technology.

In one example, the pre-processing step involves the de-stalking of the plant material. The stalks of the cannabis plant are of comparatively low value. Alternatively, the value components of the plant material may be harvested in the growing area, leaving the stalks and/or fan leaves behind.

In one example, the pre-processing step involves introducing the plant material to a cutting and/or milling machine. Preferably, during this process, the plant material is reduced to dimensions of around 1 mm to 50 mm. These dimensions may be dependent on the technology involved in the following steps of the processing method and the genetic traits of the specific plants being processed. For example, in some instances, the cutting and/or milling may reduce the dimensions of the plant material to around 1 mm to 25 mm.

In some examples of the present technology, the plant material may be cooled and/or de-humidified for a short period of time during or immediately following the pre-processing step A. In one example, the cooling may be achieved through the introduction of chilled water to the cutting and/or milling machine concurrently with the plant material. In another example, chilled air may be directed onto the plant material as it is conveyed to the cutting and/or milling machine. 5.1.2 Pre-concentration

Following pre-processing, the remaining plant material, the flowers and sugar leaves, are concentrated and then further separated into a filtrate stream and a waste stream in a preconcentration step B.

The filtrate stream should be understood to contain the overwhelming majority of the value components, i.e. cannabinoids, while the waste stream should be understood to be the low value-by product resulting from the pre-concentration step. For example, the waste stream comprises the larger particulate plant matter, such as leaves and residual stalks and stems. This waste is removed from processing at the completion of the pre-concentration step B.

An important aspect of the pre-concentration step B is the introduction of the pre-processed cannabis plant material to a quantity of cooling agent and then agitating the resulting mixture. This agitation is particularly aggressive and mechanically works the immersed cannabis plant material. This helps to expeditiously separate the value components, particularly the trichomes, from the plant material. It may also help to break up the trichomes into smaller fragments and components. When break up of the trichomes occurs, this releases the cannabinoids, in oil form, into the cooling agent.

The term cooling agent should be understood as meaning a fluid (e.g. a liquid or a gas) which reduces the temperature of the plant material when they come into contact with each other. In one form, the cooling agent is a slurry of chilled water and particulate ice, in the form of cubes or chunks, that has been reduced in temperature to substantially 0° Celsius, or close to 0° Celsius. This is advantageous for when trichomes are exposed to temperatures close to freezing, they become brittle and are more easily separated from the flowers and leaves of the plant material with appropriate agitation action.

In another example, the cooling agent may be brine (salt water) with particulate ice. This may be useful since brine can be used in following steps for rinsing the filtrate. Its use as a cooling agent could optimise the efficiency of the processing of the filtrate. It also allows for the further reduction of the temperature of the cooling agent since brine has a lower freezing point than fresh water. In further examples, the cooling agent may include additives for the purpose of improving efficiencies in the processing of the filtrate. In one such example, a pH adjuster, such as salt, may be introduced to the slurry of ice and water. In another such example, a surfactant may be added to the cooling agent; this may assist in the separation of the trichomes from the remaining plant matter and/or cooling agent.

This reduction in temperature of the harvested plant material increases the efficiency of the preconcentration phase and the separation of the plant material being processed into filtrate and waste streams. In one example, the filtrate contains around 10% or less of the original plant material, much of which is the trichomes, that is pre-concentrated with the remaining 90% or so forming the waste stream.

The quantity of cooling agent used in the pre-concentration step B may depend on the type used and the amount of plant material to be processed at any one time. In one form, when the cooling agent is a slurry of chilled water and ice, the ratio of cooling agent to plant material is from 0.5:1 to 10:1 or, more preferably, 1:1 to 5:1. In a particularly preferred form, the ratio of cooling agent to plant material is approximately 2:1.

The present technology relates to a system, apparatus and method of using same to perform the preconcentration step, and specifically the removal of certain parts of the harvested cannabis plant material, specifically the trichomes and their constituent components, and processing these into a filtrate stream, which contains most of the trichomes, and a waste stream. The filtrate stream then undergoes further processing to extract the trichomes. However, it should be appreciated that in some examples, not all trichomes are able to be extracted on initial processing. In these examples, at least a portion of the filtrate stream may be recirculated back into the system via a number of pathways and the method repeated to extract at least some of these trichomes. This is an important aspect of the invention as it helps make the overall processing of harvested cannabis plant material more efficient than conventional systems. This provides a method and system for processing of harvested cannabis at volumes that are more economically viable on a commercial scale of operation.

5.1.3 Clarification

The clarification step C further separates the filtrate stream by removing any remaining large particulate plant material of low value.

This may involve further fine filtering of the filtrate. Alternatively, the clarification step may involve recycling the filtrate for a period of time through the pre-concentration step previously discussed.

5.1.4 De-watering

After the clarification step, the filtrate is predominately a liquid containing the remnants of the trichomes and a significant water content. The de-watering step D involves the use of conventional filtration techniques as should be known by the skilled addressee and dehumidification to reduce the moisture content and dry the filtrate and leave behind a substantially solid mass of material.

5.1.5 Extraction

To extract target compounds, e.g. cannabinoids from the dried filtrate, known extraction techniques may be employed by the skilled addressee in an extract step E. In one example, a solvent such as ethanol may be used, in combination with filtration techniques.

This may allow the constituents of the trichomes to become aggregated and more easily separated out. The efficiencies that may be achieved with the present invention may also require less ethanol to be used at this stage of the process. The filtrate after the preceding steps may have a greater trichome content than with conventional techniques, and as such is more easily separated out.

5.1.6 Refining

The extract of the previous step may be further processed in a refining step F using conventional distillation and/or crystallisation/chromatography techniques that will be readily understood by the skilled addressee. 5.2. System

In one example illustrated in Figure 2, the system (generally indicated by 100) of the present technology includes a vessel 102 provided with a filtering medium in the form of a basket 104. In the illustrated example, the system also includes an agitator 106 disposed within the basket. In use, this serves to stir and vigorously agitate the mixture of cannabis plant material and cooling agent when introduced to the vessel, as will be discussed below. However, other examples of the system may employ other means of agitating the mixture; for example, a static mixer (not shown) may be employed downstream of the vessel. Alternatively, a pump (not shown) may be used for this purpose.

The agitation is an important aspect of the invention. Aggressive agitation, compared to the more gentle methods used in the prior art, breaks and shreds the cannabis plant material and releases more trichomes into the cooling agent. This potentially optimises the extraction of the value components from the cannabis plant material.

The vessel, basket and, if present, the agitator, are arranged and configured to best optimise the implementation of the pre-concentration step of the processing method.

In some examples, the system 100 may also include a transfer mechanism (not shown in Figure 2 but identified as 300 in Figure 3) that places and removes the baskets 104 and/or agitators 106 into and out of the vessels 102 as required.

The respective essential and optional parts of the system used to perform the method shall now be described in detail.

5.2.1. Vessel

Each vessel 102 should be understood to be a container that in use receives the plant material being processed and a quantity of cooling agent. In this example, the separation of the plant material into filtrate, a mixture or slurry of plant material and cooling agent, and waste streams takes place within the vessel. However, in some examples, the separation of the filtrate may take place downstream of the vessel.

In one example of the present technology, the vessel 102 is an open tank, with at least its internal surface configured as a cylinder and thus having substantially a circular cross-section. However, this is not meant to be limiting and other shapes and profiles for the vessel will be readily envisaged by persons skilled in the art. The vessel shall now be referred to as a tank throughout the remainder of the present specification.

The tank 102 has a continuous side wall 102a and a base 102b and is fabricated from an appropriate material, such as stainless steel or the like. In use, the tank receives the basket 104; the tank may already be pre-filled with the cooling agent prior to the introduction of the basket or alternatively, the cooling agent may be introduced afterwards.

In an example, the tank 102 has a diameter of approximately 2 metres and has a height that is at least twice its diameter. In this configuration the tank has a volume of approximately at least 4,000 litres. However, it will be appreciated by persons skilled in the art that the dimensions of the tank may be scaled up or down depending on the intended volume of harvested cannabis plant material that is intended to be processed at any one time.

The tank 102 is provided with an outlet 108 as seen in Figure 2, which in one example is located or otherwise positioned at or proximate the base 102b. This allows liquids received by the tank to be drained away for further processing. It will be appreciated that at least some of the drained liquid is the filtrate stream (which shall now be referred to as the filtrate). The filtrate contains trichomes and their cannabinoids of interest as suspended particulate matter within the filtrate.

The base 102b of the tank 102 may be flat, with the outlet 108 positioned centrally or alternatively as shown in Figure 2, at a lower edge of the side wall 102a. In other examples, the base of the tank may be in an inverted conical form, with the outlet positioned at the lower most point; this configuration may help with efficient drainage of the liquid contents of the tank. The outlet 108 is communicative with a discharge pipe 110. This may be under pressure to better optimise flow of the drained liquid and filtrate through the pipes. In some examples, the outlet may include a screen to capture any larger particulate matter that may have escaped the filtering medium and prevent it entering the filtrate.

In some examples, the tank 102 is configured with a supply line or charger (not shown) for the introduction of the cooling agent. This may be to the sides of the tank or alternatively, a separate structure entering the open top of the tank.

5.2.2. Filtering medium

The filtering medium should be understood to be a container that is configured to act as a filter. In one example, the filtering medium is a basket 104 and shall be referred to as such throughout the remainder of the present specification.

In use, the harvested and pre-processed cannabis plant material is placed 112 within the basket 104. This may be by hand or alternatively may be through the use of a charger or hopper or the like (not shown) as will be readily apparent to a skilled addressee.

It will be appreciated that in preferred examples of the present technology, the basket 104 is configured to be substantially complementary to the tank 102 of the system 100. In a particular example of the present technology, the basket is a cylindrical structure having a continuous side wall 104a and a base 104b. It will be appreciated that in this example, the tank that receives the basket is similarly a cylindrical structure.

In one example, the dimensions of the basket 104 are such that it is 5% to 20% smaller than the tank 102 in which it is to be placed. This means that when centrally located within the tank, there is clearance 114 between the continuous wall 104a and base 104b of the basket and that of the tank.

In one example, the basket 104 may be between 1.9 to 1.4 metres in diameter and 3.8 to 3.2 metres in height. However, it will be appreciated by persons skilled in the art that, as previously noted in respect of the tank 102, the dimensions of the basket may be scaled up or down depending on the intended volume of cannabis plant material that is intended to be processed at any one time.

In some examples, the base 104b of the basket 104 may be configured with structures that are complementary to structures provided to the upper surface of the base 102b of the tank 102. This helps to anchor the basket relative to the tank, particularly if the contents of the basket are being stirred through the action of the agitator 106.

In one example of the present technology, the basket 104 is fabricated from stainless steel sheet having perforations of approximately 0.3 mm to 3 mm. In other examples, the walls 104a and base 104b of the basket are fabricated from stainless steel mesh.

Once filled with the plant material to be processed, the basket 104 is transferred to the tank 102 for the pre-concentration phase. Alternatively, the basket is placed within the tank and freshly harvested and pre-processed cannabis plant material is then introduced to the basket. The tank may already contain the cooling agent prior to the basket being placed therein or alternatively the cooling agent is introduced to the tank after the basket.

It will be appreciated that, in use and following the introduction of the cooling agent, the basket 104 serves as a filter for the plant material being processed. The larger particulate matter forms the waste stream that remains within the basket while smaller particulate matter and dissolved compounds, including the parts of particular value, the trichomes, forms the filtrate 116 which passes through the walls 104a of the basket and is allowed to exit the tank 102 via the outlet 108 along with the cooling agent. The filtrate is largely a slurry of shredded plant material, broken up into particulate matter through the action of the agitator, and cooling agent.

In other examples not shown here, the filtering medium may be a screen or the like, positioned at or proximate the outlet of the tank. The screen is dimensioned to exclude larger particulate plant matter, which is likely to be low value biomass, from exiting the tank, but smaller particulate matter and dissolved compounds, such as trichomes, may pass through along with the cooling agent. 5.2.3. Agitator

In one example of the present technology and as shown in Figures 2 and 3, the system 100 includes an agitator 106. In use, the agitator is configured to agitate and mix the contents of the tank, namely the cooling agent and harvested cannabis plant material as it is being filtered by the filtering medium 104.

As discussed above, the tank 102 may be filled with a cooling agent. In this example, the action of the agitator serves to provide the necessary forces to encourage physical breakdown of the plant material. In particular, the agitator encourages separation of the now significantly cooled trichomes from the remaining plant material so that they become entrained in the cooling agent as a suspended particulate matter. This is an important aspect of the present technology.

Referring to Figure 2, in one example, the agitator 106 comprises an elongate, vertically orientated shaft 118. A plurality of agitating blades or tines 120 extends substantially perpendicularly from the shaft at regular intervals.

The agitator 106 is provided with a drive motor 106a to rotate the agitator about a vertical axis. This action, with the blades 120, serves to mix and agitate the immersed plant material and encourage the separation of same into the low value waste and the high value filtrate.

In examples, the motor 106a acts to rotate the agitator 106 at speeds ranging from 20 to 200 revolutions per minute or more. The higher speeds are preferred for aggressive agitation and breakdown/shredding of the immersed plant material to release the trichomes containing the cannabinoids of interest. It can also help in breaking down of the trichomes into fragments.

In some further examples, the motor 106a may be set to provide, at regular intervals, a pulsing action where the speed of rotation is increased for a period of time. Alternatively, the motor may be operative such that for a period of time, the agitator rotates in a first direction, and then a second direction. In both of these examples, this enhances the effect of the agitator upon the plant matter. In some further examples not shown here, to supplement the effect of the agitator, the blades may be configured with tines or the like extending in various orientations to further thresh the plant material in various directions when the agitation is in motion.

In the illustrated example, the base 106b of the agitator 106 may be configured to key into or otherwise engage with the basket 104, preferably at the base 104b of the basket. In preferred examples, this may be by way of a bearing hub or the like. This helps ensure the structural integrity and minimise stresses during operation of the agitator.

In one example, at least a portion of the shaft 118 of the agitator 106 is hollow, with a series of apertures 118a allowing communication between the interior of the shaft to the exterior, arranged at regular intervals along its length. In this example, the agitator is provided with a pipe 124 for pressurised chilled water which is directed through the hollow tube of the shaft and out the apertures provided along same. In some examples, the apertures may be configured with nozzles or similar structures to help optimise the desired radial flow path.

In use, the pressurised water that is directed through the shaft 118 of the agitator 106 and emitted out the apertures 118a serves two purposes. Firstly, depending on the extent of the pressure at which it exits the shaft of the agitator, it provides some impact forces on the plant material, supplementing the action of the agitator and assisting in the separation of trichomes from the plant material. Secondly, it creates a radial flow path within the basket and tank, encouraging further separation of the finer particulate plant matter, including the trichomes, from the plant material being processed and directing this towards the space 114 between the basket 104 and the inner surfaces of the tank 102.

In some examples, the cooling agent may be introduced to the tank via the hollow shaft 118 of the agitator 106 as shown in Figure 2 but in other examples, as previously discussed, the cooling agent may be delivered to the tank via a separate charger or supply line. In a further example, the agitator 106 may include a scraper 122 which, in use, bears against the continuous wall 104a of the basket 104 and scrapes its surface. In one form, the scraper is an elongate bar 122a mounted to a pair of arms 122b extending perpendicularly from the shaft of the agitator; as the agitator rotates, so does the scraper. This helps optimise the filtering of the plant material performed by the continuous wall and/or base of the basket, minimising any blockages that may occur.

In some examples, the scraper 122 may be configured to receive a plastic insert (not visible) which is the scarping surface that contacts the continuous wall 104a of the basket 104 in use. In this form, the use of the plastic insert reduces the risk of damage to the walls of the basket.

In some examples, the scraper 122 may be arranged to encourage the development of the radial flow path that directs the filtrate 116 towards the space 114 between the basket 104 and tank 102.

5.2.4. Transfer mechanism for Basket and/or Agitator

In one example of the present technology as shown in Figure 3, the system 100 is provided with a transfer mechanism 300 to facilitate the placement of the basket 104 and/or agitator 106 within the tank 102. On the left in dashed lines is an agitator in a stored position and on the right an agitator shown in an "in use" position, where it is disposed within the tank.

In its simplest form, the transfer mechanism 300 includes lifting equipment in the form of a winch 302 provided with a hook 304 and cable 306 which engage with complementary fittings (not visible) provided to the upper surfaces of the agitator 106 and baskets 104. In alternative examples not shown, the cable may be provided with a loop which engages with hooks or similar fittings provided to the agitator and baskets. The skilled addressee should readily envisage and implement a transfer mechanism suitable for use with the present system.

In some examples, the transfer mechanism may include a gantry 308 along which the lifting equipment 302 is able move. This allows the basket 104 and/or agitator 106 to be moved to a location clear of the tank 102. In some examples, the agitator 106 may be provided with a frame or support stand 310 for when it is not in use. When the agitator is located within the frame, the transfer mechanism 300 may be used to place the basket 104 in the tank 102 and/or remove it from same.

5.2.5. Separator

In one example of the present technology as shown in Figure 2, the system 100 includes a separator 132 which will be understood to be downstream of the tank 102 and receives laden quantities of filtrate 116 via the outlet 108 and discharge pipe 110 of the tank. The separator will be understood to be an apparatus that processes the filtrate into a high value stream and a low value stream; the former includes the trichomes of interest while the latter may be spent or partially spent cannabis plant material from which at least some of the trichomes have been removed.

The discharge pipe 110, pressurised by a pump 134, deposits the filtrate to and through the filter screen 136 of the separator 132. In this example, the screen includes apertures ranging in size from one to 200 microns. The filter screen therefore captures relatively large components in the filtrate. Surplus liquid, i.e. cooling agent, passes through the filtering surface and may be pumped back to the tank. In conventional systems, this surplus cooling agent is regarded as a waste stream and is discharged. In the present invention it is recognised that there may be still value components entrained in the surplus cooling agent, and hence returning it to the tank provides a further opportunity for extraction of those value components.

The filtrate may still contain target compounds such as cannabinoids. These compounds can be subsequently removed from the filtrate by additional processing steps (as are discussed in more detail below or as should be known to the skilled addressee).

The use of the separator 132 further processes the filtrate by separating out at least some of the target compounds from the filtrate e.g. the trichomes or relatively large aggregates. It also serves to filter out at least some of the cooling agent 137 used in the method. This cooling agent passes through the filter screen and may be collected and recycled into the tank 102 for re-use for further processing as required. As noted previously, this is an advantage of the invention, since it provides further opportunity to capture any value components, trichomes or fragments of trichomes, missed by the separator, minimises wastage of the cooling agent, and also optimises the processing of the plant material.

As shown in Figure 2, this is via the pipe 124 that is communicative with the shaft 118 of the agitator 106 (or it could just as easily be via a separate pipeline back to the tank 102). In doing so, the cooling agent is pumped 139 through a chiller 141 to reduce its temperature.

The remaining filtrate 138, once processed by the separator, flows off the screen 136 and is collected for further processing (140 - for example, the clarification and/or dehumidification steps previously referred to in the discussion of Figure 1). Instead of an angled filter screen, as shown in Figure 2, in one form the separator may be one or more cyclonic separators. In other forms, the separator may comprise one or more rotary or fixed filters, with a screen of between 1 to 200 microns. Persons skilled in the art will readily utilise and/or adapt known separators suitable for use in the present system.

5.2.6. Recirculation loops/pathways

Not all of the trichomes, especially if broken up into their constituent parts, may be captured when the filtrate is passed over the separator. To optimise the extraction of these value components, the trichomes containing the desired CBD and THC, from the plant material being processed, the system as previously described may be provided with one or more recirculation loops to direct what may otherwise be deemed as a waste stream from the separator for further processing by the present invention. The system may also be provided with additional means of agitating the filtrate following its exit from the tank prior to being introduced to the separator. These recirculation loops may provide further opportunities to extract trichomes not captured on an initial pass over the separator.

An embodiment of the invention employing such recirculation loops is described in Figures 4 to 7. Referring firstly to Figure 4, this shows a schematic of a system 400 (features common to the embodiment of the system previously described in Figures 2 and 3 use like numbers) with recirculation loops 500 and 600 and pathway 700. These are shown in bold in Figures 5, 6 and 7 respectively.

The system 400 includes a tank 102, which in use contains a slurry of the cooling agent and harvested cannabis plant material (not shown). Once the tank has been filled to the prescribed level, the agitation of the slurry through the action of an agitator 106 may commence after a period of time has elapsed. This is to ensure that the slurry has cooled sufficiently for the trichomes to become brittle and potentially more easily separated from the rest of the plant material and/or broken up and fragmented.

In operation, the agitator 106 acts upon the slurry as previously described, breaking up the plant material, separating the trichomes from the leaves, and potentially assisting in the breakdown of the trichomes into fragments or even their constituent components, which occurs when the trichomes break open and release the cannabinoids, in oil form, into the cooling agent. This action may be performed for a designated period of time before the filtrate is allowed to begin exiting the tank. In one, non-limiting example, this may be for at least 30 to 90 minutes. It should be appreciated that aggressive agitation of the slurry can potentially reduce the time required for agitation and break up of the plant material. Following the initial agitation phase, the system may then be allowed to run continuously, with filtrate allowed to exit the tank for transfer through the system at a consistent flow rate.

The larger particulate plant material is retained within the tank 102 by a filtering medium (not shown) while the filtrate, a liquid mixture of cooling agent, with entrained smaller particulate plant matter, including the trichomes and their fragments, not captured by the filtering medium, exits the tank and through the use of a pump 402 is passed along a pipeline 404 through to an optional static mixer 406. The action of the pump upon the filtrate helps with the separation and breakup of the trichomes within the filtrate. The action of the static mixer has a similar effect upon the filtrate. This repeated aggressive agitation, firstly in the tank through the action of the agitator and during the subsequent transfer of the filtrate from the tank to the separator is important and helps optimise efficiencies.

In some examples not shown here, the agitator 106 may not be present in the system 400. Instead, the agitation of the filtrate may be performed through the action of the pump 402 and/or the static mixer 406. In other examples, an agitator, pump and static mixer may all be present in the system; this may mean a particularly aggressive agitation of the filtrate can be achieved, further optimising processing time.

From the static mixer 406, the filtrate is passed through a screen 408 with apertures ranging in size from one to 200 microns (50 to 150 microns is preferred) in order to separate at least a portion of the liquid content, which is essentially the cooling agent, i.e. chilled water, from the particulate plant matter entrained within, much of which is the valuable trichomes.

In the illustrated system 400, the screen 408 is a scrape surface filter 410. This should be understood a screen 412 with a mechanical scarper (not visible) acting against the screen to minimise or prevent build up of solid matter. It should be noted that this is not intended to be limiting and other screening apparatus may be used.

In this manner, the majority of the filtrate that was transferred from the tank 102, at least 20% to 70%, which is largely cooling agent, is separated and returned to the tank; the remaining 30% to 80% of the filtrate, with a much high percentage of solid matter relative to liquid, is transferred to the separator 132.

The return of the majority of the filtrate in this first recirculation loop 500 is achieved through the use of a pipeline 414 extending between the scrape surface filter 410 and the tank 102. The pathway of the first recirculation loop, from tank to the scrape surface filter and back to the tank is shown in bolded lines in Figure 5.

It should be appreciated that there may be considerable inefficiency in the filtering action of the scrape surface filter 410. The use of the first recirculation loop 500 allows the greater portion of the filtrate to be returned to the tank 102 for further agitation and breakup of the entrained plant matter therein. Additionally, some trichomes will have been fractured or broken open and fragments of same may still be entrained, having failed to be captured by the scrape surface filter 410. In some examples, these may be extracted from the cooling agent by further processes before the filtrate re-enters the tank. The extracted trichomes and/or cannabinoids may then be added to those extracted out through the action of the separator 132.

In some examples, concurrently with this first recirculation loop 500, more freshly harvested cannabis plant material may be introduced to the tank 102 via a charger (not shown) or a worker (not shown) depositing it into the tank. This allows the system 400 to operate nearly continuously, until there is an excessive amount of large particulate matter within the tank. This may need to be cleared so that the tank can be cleaned and prepared for a fresh batch of harvested cannabis plant material.

In other examples, concurrently with the first recirculation loop 500, more cooling agent may be introduced to the tank 102 via a charger (not shown). This may be instead of adding freshly harvested cannabis plant material or in addition.

This arrangement allows the system 400 to operate near continuously. It will be appreciated that this also keeps the volume being processed by the system substantially consistent. Once processing commences, the input (harvested cannabis plant material and cooling agent) into the system is the same as or substantially approximates the output (the filtrate extracted by the separator) from the system. Alternatively, the system may be run without topping up with plant material and/or cooling agent. This means that the volume will be gradually reduced in volume as filtrate is removed from the system by the separator.

As noted above, the remaining filtrate is passed through to the separator 132. The flow rate of the filtrate from the screen 408 to the separator may be controlled through valve 415 to help ensure that there is no overload, which could otherwise compromise the efficiency of operation. Still having a large liquid content, the separator acts to further reduce the amount of cooling agent which, as previously noted is chilled water, present in the filtrate.

The water extracted at this stage is fed back into the tank 102 via a second recirculation loop 600, as shown in bolded lines in Figure 6. Of the portion of the filtrate that reached the separator 132, around 30% to 80%, through the use of pump 416 is returned to the tank via a pipeline 417. This portion of the filtrate is largely made up of cooling agent although some trichomes will have been fractured or broken open and fragments of same may still be entrained, having failed to be captured either by the scrape surface filter 410 or the separator.

In some examples, as with the recirculation loop described in Figure 5, the entrained fragments of trichomes and/or the contents of the trichomes may be extracted from the cooling agent by further processes before it enters the tank 102.

Before its reintroduction to the tank 102, this portion of the filtrate is passed through a chiller 418 to bring its temperature back to 0° Celsius, or as close as possible to 0° Celsius.

In Figure 7, a portion is of the filtrate is separated out through the action of the separator 132 of the system 400. This filtrate is largely a solid resinous mass 702 of trichomes and/or cannabinoids. This final portion of the filtrate may form as little as 5% to 20% of the original amount transferred from the tank 102, the balance being the liquid portion that has been returned to the tank through the use of the first 500 and second 600 recirculation loops. The pathway 700 of the final portion of the filtrate from the tank 102, pump 402, static mixer 406 and scrape surface filter 410 to the separator is shown in bold. This mass is collected and then transferred for further processing, for example, de-watering and extraction of the CBD and THC with solvents.

The removal of the filtrate from the system 400 may result in a reduction in volume of material being processed. As previously described, this may be compensated for by topping up the system with additional harvested cannabis plant material and/or cooling agent. It should be appreciated that in the system 400 of Figures 4 to 7, the first and second recirculation loops 500, 600 are operated concurrently with pathway 700. This optimises processing of the harvested cannabis plant material and the extraction of the value components from same while minimising wastage of both cooling agent and plant material.

5.2.7. Operation

The operation of an individual tank of the present invention as illustrated in Figures 2 and 3 involves certain key steps. For sake of understanding the operation, and only be way of example, the explanation assumes the tank is dimensioned to have an internal diameter of approximately 2 metres and an internal height of approximately 4 metres, giving an overall operating volume of approximately 4,000 litres. As previously noted, the skilled addressee will readily understand that the tank may be scaled up or down depending on the volume to be processed and therefore may adjust the timing of the operation accordingly.

5.2.7.1. First step

To begin the process, a batch of the cannabis plant material to be separated out into waste and filtrate is introduced into the tank 102, separately or concurrently with an appropriate amount of cooling agent. The batch is allowed to be fully immersed in the cooling agent, a slurry of chilled water and ice cubes in this example, and have its overall temperature reduced to the point where the trichomes become brittle and more easily separated from the remaining plant material.

In one example, depending on rate of charging of the plant material and chilled water, this first step may take up to 30 minutes.

5.2.7.2. Second step

The mixture of plant material and chilled water and ice is then vigorously agitated through the use of the agitator 106 and allowed to circulate within the tank 102 and basket 104. This action helps to 1 separate the smaller particulate matter, including the trichomes, from the larger portions of the plant material being processed and into a filtrate.

After a designated period of time, or throughout this process, the filtrate is allowed to exit the tank 102 via the outlet 108 and be directed to the separator 132. At the separator, the filtrate is further filtered using the filter screen 136 to extract at least a portion of the trichomes from same. These trichomes may be entrained in at least some of the chilled water used in the process.

The remainder of the filtrate, which may comprise cooling agent, particulate plant material, suspended solids (including any trichomes not extracted from the filtrate by separator 132) is directed or otherwise recirculated, via pump 139 or gravity feed, back to the tank 102. In conventional systems, this may be considered waste but it has been found that there can still be a significant amount of trichomes present in this filtrate, or able to extracted from the filtrate, to justify its further processing by returning to the tank.

5.2.7.3. Third step

Once the mixture has been agitated and recirculated for an appropriate period of time, the tank 102 can be emptied. This involves the draining of the liquid portion of the mixture, containing the filtrate, through the outlet 108 and to the separator 132.

The residual plant material, the waste from the pre-concentration step, is left behind in the basket 104 which is transferred out of the tank 102. This allows the waste to be removed.

5.2.7.4. Fourth step

To process another batch of harvested cannabis plant material, it is necessary to rinse or otherwise clean the basket and tank with water, together with, or instead of, a cleaning agent such as a mild detergent or solvent. This water is delivered through the agitator 106 (or separate supply if present) and allowed to drain through the outlet 108 of the tank 102, be removed from the system, and then recirculated as a rinsing step as desired. The time taken to perform these steps may depend on the desired efficiencies and available plant material and staff. In one example of the operation of the system, it takes approximately 150 minutes to cycle a single batch of freshly harvested cannabis plant material and the required cooling agent (collectively, approximately a volume of 4,000 litres). Over a 24-hour period, this allows for an hourly processing rate of approximately 1,600 litres through the tank.

The present method, system and apparatus is advantageous as it does away with the prolonged drying period that follows harvesting of the cultivated cannabis plants and which is required in conventional techniques. Instead, the plant material may be processed relatively quickly following its harvesting, with minimal drying or dehumidification required as a pre-processing stop. In addition, once preprocessing has commenced, the use of recirculation loops to return cooling agent back to the tank helps maximise the extraction of the valuable components of the processed plant material, while at the same minimising wastage.

The systems and methods described herein may also reduce processing times in a cost-effective manner, reduce solvent volumes required to process plant material, improve extraction efficiencies of value components from natural plant material. The forgoing advantages help maximise the extraction of the valuable components of the processed plant material, while at the same minimising wastage and potential labour costs.

Unless the context clearly requires otherwise, through the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

Wherein the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

The invention may also be said broadly to consist in the parts, elements, characteristics and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements, characteristics or features. Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined herein.

It should be noted that various changes and modifications may be made without departing from the spirit and scope of the invention as claimed and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present claims.

Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art referred to forms part of the common general knowledge in the field of endeavour in any country in the world. The disclosure of any applications, patents and publications cited herein, if any, are herein incorporated by reference.