WO2025170745A1 - Extraction system for fine particle plant stock - Google Patents

Abstract

Systems and methods for improved extraction of desirable solutes from plant stock. The system includes a cartridge which may be packed with plant stock in a perforated basket, with a solvent distribution pipe in the center of the basket and any plant stock packed in the basket. The cartridge can be packed with plant stock for transport, optionally dehydrated prior to transport, and installed in a larger system including a solvent reservoir and collection tank. The system is operable to force the solvent through the cartridge and the plant stock packed in the basket to extract desirable compounds, and collect the solvent and the desirable solute in the collection tank.

Description

Extraction System for Fine Particle Plant Stock

[0001] This application claims priority to U.S, Provisional Application 63/670, 684, filed July 12, 2024 and U.S, Provisional Application 63/549,957, filed February 5, 2024. The entirety of each is hereby incorporated by reference.

Field of the Inventions

[0002] The inventions described below relate to the field of solvent extraction.

Summary of the Inventions

[0003] The systems and methods described below provide for improved extraction of desirable solutes from plant stock. The plant stock may be hops, marijuana, hemp or other biomass, and the desirable solutes may include essential oils, lupulin, THC and CBD. For example, trichomes with essential oils from plants such as salvia, lupulin glands from hops for beer, THC or CBD in trichomes from marijuana, or CBD from hemp may all be harvested with the aid of cryogenic separation.

[0004] The system is based on a cartridge which may be packed with plant stock in a perforated basket, and a solvent distribution pipe in the center of the basket and any plant stock packed in the basket. The cartridge can be packed with plant stock for transport, optionally dehydrated prior to transport, and installed in a larger system including a solvent reservoir and collection tank. The system is operable to force the solvent through the cartridge and the plant stock packed in the basket to extract desirable compounds, and collect the solvent and the desirable solute in the collection tank. The system may also include a flushing fluid reservoir and means for forcing flushing fluid through the plant stock to agitate wetted plant stock and promote uniform wetting of the plant stock with the solvent . The system may also include a bubble inj ection system operable to inj ect bubbles , including microbubbles or nanobubbles , into the solvent , to promote extraction .

Background of the Inventions

[ 0005 ] Figure 1 illustrates a prior art solvent extraction system which may be used to expose fine particle plant stock to a solvent to remove desirable solutes from the plant stock . The system comprises a tower 1 which includes a perforated basket 2 disposed within a can 3 , capped of f with end caps 4 , 5 on both ends , with an inlet 6 for a solvent in the end cap of one end and an outlet 7 in the wall of the can . In use , the system is assembled with the perforated basket within the can, and both end caps secured to the ends of the can, and a solvent supply is aligned with the input, and the solvent and solute exits the system for collection and further processing . Plant stock is placed in the perforated basket , and a solvent is inj ected through the inlet and into the perforated basket . The solvent and any dissolved solutes exit the perforated basket through the numerous perforations in the wall of the perforated basket and collect in the can before it exits the can through the outlet to be collected in a collection tank .

[ 0006] When used with very fine particle stock, such as cannabis trichomes and particles derived from trichomes , the stock may become very tightly packed . Mere inj ection of solvent from the end of the can result in only partial wetting of the stock within the perforated basket, leaving signi ficant large regions of stock dry and unaffected by the solvent , and packed column of stock can be quite resistant to passage of solvent .

Brief Description of the Drawings

[ 0007 ] Figure 1 illustrates a prior art solvent separation system.

[ 0008 ] Figure 2 illustrates a cartridge for use in a solvent supply system suitable for use with tightly packed small particle and fine particle plant stock .

[ 0009] Figure 3 illustrates an extraction system with the cartridge of Figure 2 with a gas agitation system .

[ 0010 ] Figure 4 illustrates a cartridge for use in the system of Figure 3 .

[ 0011 ] Figure 5 illustrates the solvent extraction tower 1 of Figure 2 and 3 with the addition of a bubble inj ection system.

Detailed Description of the Inventions

[ 0012 ] Figure 2 illustrates cartridge and can assembly for the improved extraction system 8 for use in a solvent extraction system. In addition to the perforated basket 2 disposed within a can 3 , capped of f with end caps 4 , 5 on both ends , and the inlet for a solvent in the end cap 4 , 5 of one end ( or both ends ) and an outlet 7 ( or outlets ) in the wall of the can, this system includes a central solvent distribution pipe 9 is disposed within the perforated basket 2 for inj ection of solvent along the length of the perforated basket 2 and any packed stock within the tube . The central solvent distribution pipe 9 has numerous apertures or perforations in the wall of the pipe , dispersed along its length, to allow solvent to exit the pipe and enter the packed plant stock at numerous positions along the length of the column of plant stock . The perforations of the basket are si zed and configured to retain plant stock within the basket yet allow passage of the liguid solvent and any solutes through perforations in the wall of the basket .

[ 0013] In use, the system is assembled with the perforated basket within the can, the solvent distribution pipe 9 disposed within the perforated basket 2 and both end caps 4 , 5 secured to the ends of the can 3 , and a solvent supply is aligned with the input, and the solvent is inj ected into the pipe 9 and solute exits the system for collection and further processing . Plant stock is placed in the perforated basket , and a solute , such as cold ethanol , butane or propane is inj ected through the inlet and into the pipe from which it enters the perforated basket to wash over the plant stock . The solvent and any dissolved solutes exit the perforated basket through the numerous perforations in the wall of the perforated basket, and exit the can through the outlet to be collected in a collection tank .

[ 0014 ] Figure 3 illustrates the solvent extraction tower 1 of Figure 2 along with a depiction of the solvent extraction system. The system includes a solvent supply reservoir 10 and solvent supply line 11 in fluid communication between the solvent reservoir and the inlet 6 and the central solvent distribution pipe 9 through the inlet aperture 6A of the central solvent distribution pipe 9, a flushing fluid reservoir 12 and flushing fluid supply line 13 in fluid communication between the flushing gas reservoir and the inlet 6 further to the central solvent distribution pipe 9, and a collection tank 14 and an solvent/ solute exit line 15 in fluid communication between the can outlet 7 and the collection tank . Nitrogen or other inert or non-reactive gas may be used as the flushing fluid . In this configuration, the inlet 6 communicates immediately into the central solvent distribution pipe 9 ( rather than the entire volume of the basket as in Figure 1 ) . In the main, this system operates as described above . The flushing fluid can be occasionally inj ected into the solvent supply pipe to agitate and disrupt the plant stock and thereby open pathways for flow of the solvent , and thereafter resume solvent flow through the solvent distribution pipe 9.

[ 0015 ] The system includes means for selectively connecting the supply pipe with the solvent reservoir and the flushing fluid reservoir to the supply pipe, such as a control valve 16 , which may be a three-way valve ( a control valve having a first configuration placing the solvent reservoir in fluid communication with the supply pipe and having a second configuration placing the flushing fluid reservoir in fluid communication with the supply pipe ) , a mixing valve ( operable to supply a mix of flushing fluid and solvent simultaneously to the supply pipe ) , or a gang of independently operable valves . Means for forcing solvent and flushing fluid into and through the basket and any plant stock within the basket may include the pressuri zation of the reservoirs , one or more pumps disposed between the reservoirs and the supply pipe , or pumps disposed in the outlet of the can or in fluid communication with the collection tank .

[ 0016] The solvent is preferably ethanol , butane , propane or other solvent suitable for dissolving the desired compounds in cannabis trichomes , and is preferably cooled to cryogenic temperature of about -80 ° C ( to avoid extracting undesirable compounds in the stock) . The gas reservoir may contain nitrogen or other gas that will not react with the solute. The gas is preferably supplied at high pressure. Again, means for forcing solvent and flushing fluid into and through the basket and any plant stock within the basket may include the pressurization of the gas reservoirs, one or more blowers or pumps disposed between the flushing fluid reservoir and the supply pipe or distribution pipe, or again a vacuum pump disposed in the outlet of the can.

[0017] In use, the system of Figure 3, with the supply pipe disposed within the basket, can be operated by (1) freezing the plant stock to a low temperature and packing the basket with frozen plant stock, disposed in the space between the supply pipe and the inner wall of the basket, (2) passing cold nitrogen (preferably liquid) through the supply pipe, pre-packed with cold plant stock, to cool the plant stock further, and exhausting the cold nitrogen gas from the can for disposal or collection, (3) passing cold solvent through the supply pipe, and through the biomass, to dissolve the desired compounds in plant stock (typically, cannabinoids and terpenes, THC and CBD) into the solvent, and exhausting the solvent with the solute of desired compounds from plant stock from the can to the collection tank. The solvent and solute can thereafter be separated from the desired compounds from plant stock (by boiling off the solvent, at temperatures depending on the solvent used (butane, for example, boils at 31°F/-0.5°C) ) .

[0018] Solvents used in the system may include as ethanol, butane, propane, ethane, isopropyl alcohol, heptane, hexane, ethyl acetate.

[0019] The entire process of extraction, from harvest of plant stock to separation from the solvent, can be made more efficient with modi fications to the process . The basket and supply pipe may be provided as easily removable and replaceable cartridges ( a container configured to hold a quantity of plant stock) , or the basket may be provided, without the supply pipes , as an easily removable cartridge configured to accept supply pipes after being packed with plant stock . The plant stock may be processed at a first location, typically near the point of harvest , and packed into the baskets . Processing and packing may include the steps of grinding or milling the plant stock to a fine powder, freeze-drying the fine power to remove much of the water content , and filling a number of cartridges with the plant stock, and thereafter transporting the cartridges to a second location, remote from the first location, and, in the second location, processing the plant stock with solvent to extract the compound of interest ( THC, in the case of cannabis stock, a-acids , |3-acids , and flavonoids (prenylated chaicones ) in the case of hops stock) . For the purpose of interpreting the claims , a location is remote from another location i f transport involves travel over a signi ficant distance , involving transport or shipping by truck, train or other conveyance , as opposed to transport within a single site where plant stock is harvested and processed with transport of plant stock only within the single site . Many of the advantages of the system and methods may be obtained with harvesting, packing and optionally drying at a site remote from the site of extraction, while advantages of the systems and methods of harvesting and packing in a cartridge followed by extraction with a cryogenic solvent may be obtained with those step accomplished at a site not remote ( colocated, perhaps in the same facility) .

[ 0020 ] A suitable cartridge and can assembly may include the basket and can of Figure 3 , as depicted in Figure 4 , which shows the cartridge 17 as a subset of the components of the solvent extraction tower 1 . The cartridge includes , and may essentially consists of , components necessary for packing the plant stock in the basket and shipping the cartridge to a location remote from the location of packing, including the perforated basket 2 , a cartridge end cap 18 which functions as a detachable closure configured for sealing and unsealing the top opening 2T of the basket , the solvent distribution pipe 9, and may also include an optional cartridge bottom cap 19 which can serve as detachable closure sealing and unsealing the bottom opening 2B of the cartridge . Either the bottom opening or top opening can serve as an inlet opening for packing the cartridge . The cartridge may be stored in bags for transport from the packing location to a second location for extraction . This cartridge may be packed through either opening, the opening may be closed with the end cap, and the packed cartridge can be bagged for transport or storage and later processing . For installation into the remainder of the system, the end caps 18 and 19 are removed, the cartridge is inserted into the can 3 , and the can is capped of f with the end caps 4 or 5 , and the supply lines are connected to the solvent distribution pipe 9 through the inlet 6 , and the collection tank is connected to the collection tank 14 . The cartridges may be installed in cans before transport to the remainder of the extraction system ( contemporaneously with packing or after transport at the location of the extraction system. Also , the solvent distribution pipe 9 may be installed in the cartridges before transport of the baskets to the remainder of the extraction system ( contemporaneously with packing) or after transport at the location of the extraction system. The solvent distribution pipe 9 may have a pointed distal end configured for insertion of the solvent distribution pipe 9 into a previously packed basket.

[0021] The method may include the steps of (1) freezing plant stock (preferably fresh cut, and de-bulked to remove larger unwanted components such as stems) to a temperature permitting the milling and handling of the plant stock and components to be processed (trichomes, in the case of cannabis or hops) . This temperature may be in the range of -40 °C or below, depending on the plant stock. (2) Milling or grinding the frozen plant stock to a small particle size (down to a few microns) . (3)

Optionally sifting the plant stock in a centrifugal sieve/sifter to separate trichomes from the plant stock (4) freeze-drying (lyophilizing) the frozen and milled plant stock to remove water in the plant stock (4) optionally Heating the plant stock to remove additional water from the plant stock (5) Optionally passing the milled plant stock through a vibratory sieve (6) packing the plant stock, after milling, (optional sifting) , freeze-drying, (optional heating) , (optional sifting) into cartridges as described above. All of these step are preferably performed as close as practical to the farm and harvest location. After packing in the cartridges, the weight of the plant stock and cartridges, having been processed to remove much of the water content, will be significantly reduced and far less expensive to ship.

[0022] The packed cartridges according to Figure 4, full of milled and dried plant stock, may be shipped to a location remote from the location of harvesting and packing, for processing as described in relation to Figure 3, to remove desired compounds from the plant stock. This method for extracting soluble compounds from plant stock, may include the steps of ( l ) milling plant stock at a first location to reduce the plant stock to small particles ; ( 2 ) providing a cartridge for use in a system for extracting soluble compounds from plant stock, where the cartridge comprises the perforated basket configured to fit within can configured to contain liquid solvent containing solutes from the plant stock, with the perforated basket configured to retain plant stock within the basket and allow passage of the liquid solvent containing solutes through the perforations in a wall of the basket, and with basket having an inlet opening configured to allow packing of plant stock into the basket and a solvent distribution pipe within the basket with an inlet for connection to a solvent supply line and a flushing fluid line , and a detachable closure configured for sealing and unsealing the inlet opening of the basket , ( 3 ) packing the small particles of plant stock into the basket of the cartridge at the first location; ( 4 ) optionally freeze-drying the plant stock at the first location, either before or after packing the small particles of plant stock into the basket of the cartridge ; ( 5 ) transporting the cartridge to an extraction system at a second location remote from the first location, and, at the second location ( 6 ) installing the cartridge packed with plant stock in the into the can and connecting the supply pipe of the cartridge to the solvent reservoir and the flushing fluid reservoir of an extraction system for extracting soluble compounds from the plant stock packed in the cartridge . The extraction system may be that of Figure 3 , and include the solvent reservoir containing a solvent suitable for dissolving good stuff from the plant stock to create a solution containing the solvent and solutes extracted from the plant stock, the flushing fluid reservoir containing a flushing fluid that is non-reactive with the plant stock; the collection tank for storage of solvent and solute ; the can configured to hold the cartridge within a volume of the can, said can having an outlet for connection to a collection tank, means for selectively connecting the supply pipe of the cartridge with the solvent reservoir and the flushing fluid reservoir to the supply pipe ; and means for forcing solvent and flushing fluid through the basket and any plant stock within the basket , and forcing solvent and any solutes dissolved in the solvent into the collection tank . With the cartridge installed in the system, the system may be operated to extract compounds by forcing solvent through the supply pipe , through the plant stock, to extract solvent compounds of interest from the plant stock and pass the solvent and extracted solute compounds into the collection tank, and also by forcing flushing fluid through the supply pipe, through the plant stock and through perforations in the wall of the basket ; and, finally, separating the solvent from the extracted solute compounds to recover the extracted solvent compounds of interest . Flushing fluid may be inj ected at various points in the procedure and at various points in the basket .

[ 0023] For example, flushing fluid may be inj ected through the supply pipe and into the plant stock disposed in the basket , to cool the plant stock to a temperature colder than an initial temperature of the plant stock, or prior to an initial inj ection of solvent, to cool the plant stock to a temperature colder than an initial temperature of the plant stock, especially while the plant stock is dry, before being wetted with solvent , to cool the plant stock to a temperature colder than an initial temperature of the plant stock .

[ 0024 ] Figure 5 illustrates the solvent extra21ction tower 1 of Figures 2 and 3 , including the previously described solvent supply reservoir 10 and solvent supply line 11 in fluid communication between the solvent reservoir and the inlet 6 , the nitrogen gas reservoir 12 and nitrogen supply line 13 in fluid communication between the gas reservoir and the inlet 6, and the collection tank 14 and the solvent/ solute exit line 15 in fluid communication between the can outlet 7 and the collection tank . In addition to the nitrogen gas reservoir 12 and nitrogen supply line 13 , the system of Figure 5 includes a bubble inj ection system ( a sparge system) 21 including a bubble gas reservoir 22 and bubble gas inj ection line which extends into the solvent supply line ( item 23 ) upstream of the central solvent distribution pipe 9 or a bubble gas inj ection line which extends deep into the central solvent distribution pipe 9 ( item 24 , which bypasses valve 16 ) or elsewhere in the system such as the solvent supply reservoir 10 or directly in the biomass between the central solvent distribution pipe 9 and the perforated 2 .

[ 0025 ] The sparge gas inj ection system 21 is configured to inj ect micro-bubbles , nano-bubbles , or both, into the solvent . Nano-bubbles are bubbles in the si ze range of 1 um ( 1000 nm) or smaller, and preferably in the range of 300nm or smaller . Micro-bubbles are bubbles in the si ze range of larger than 1 um and up to 100 um ( 1000 nm to 100 , 000 nm) , and preferably in the range of ( greater than) 1 um and up to 10 um. The fluid used in the reservoir to make the sparge microbubbles or nanobubbles may be gas , preferably an inert gas (noble gases , nitrogen, CO2 or other gases not reactive with compounds in the biomass ) or a solvent gas (butane , propane, etc . ) . The bulk solvent from the solvent reservoir 10 remains a liquid while the inj ected sparge gas forms stable bubbles within the solvent cryogen . The sparge gas may be maintained in the reservoir at ambient temperatures or pre-chilled cold, and upon entry into the solvent may cool further ( to -50 C ° (butane ) or -40c (propane ) , as two examples ) .

[ 0026] The sparge gas inj ection system enables a method of extracting desirable solutes from plant stock which can be used alone or together with the method described in relation to Figures 2 through 3 . The method of using the bubble inj ection system of Figure 5 includes packing the perforated basket with plant stock, forcing the liquid cryogen solvent from the reservoir, through the solvent distribution pipe 9 and hence to . the collection tank 14 , and the further step of inj ecting bubbles into the solvent at a point upstream of the plant stock ( that is , inj ecting bubbles into the solvent at a point in the solvent flow path ( 9 , 10 , 11 ) prior to the plant stock and/or the annular space between the solvent distribution pipe 9 and the perforated basket . ) As above, the solvent and solute can thereafter be separated from the desired compounds from plant stock (by boiling of f the solvent, at temperatures depending on the solvent used (butane , for example , boils at 31 ° F/- 0 . 5 ³ C ) ) , and the gas making up the bubbles may be removed from the combined solvent/bubble/extract mixture . I f the bubble gas is the same compound as the solvent, it will be removed with the solvent .

[ 0027 ] The elements of the various embodiments may be incorporated into each of the other species to obtain the benefits of those elements in combination with such other species , and the various beneficial features may be employed in embodiments alone or in combination with each other .

Claims

We claim :

1 . A method for extracting soluble compounds from plant stock, said method comprising the steps of : milling plant stock at a first location to reduce the plant stock to small particles ; providing a cartridge 17 for use in a system for extracting soluble compounds from plant stock, said cartridge comprising : a perforated basket 2 configured to fit within a can 3 configured to contain liquid solvent containing solutes from the plant stock, said perforated basket 2 configured to retain plant stock within the basket and allow passage of the liquid solvent containing solutes through perforations in a wall of the basket , said basket having an inlet opening ( 2T or 2B ) configured to allow packing of plant stock into the basket ; a solvent distribution pipe 9 disposed within the basket 2 , said solvent distribution pipe having an inlet aperture 6A for connection to a solvent supply line 11 ; a detachable closure ( 18 or 19 ) configured for sealing and unsealing the inlet opening ( 2T or 2B ) of the basket ; and packing the small particles of plant stock into the basket of the cartridge at the first location; transporting the cartridge 17 to an extraction system 8 at a second location remote from the first location, and, at the second location; providing an extraction system 8 for extracting soluble compounds from the plant stock packed in the cartridge , said system comprising : a solvent reservoir 10 containing a solvent suitable to dissolving so i mfcs from the plant stock to create a solution containing the solvent and solutes extracted from the plant stock; a collection tank 14 for storage of solvent and solute ; a can configured to hold the cartridge within a volume of the can, said can having an outlet for connection to a collection tank; means 16 for selectively connecting the solvent distribution pipe 9 of the cartridge with the solvent reservoir 10 ; and means for forcing solvent through the basket and any plant stock within the basket, and forcing solvent and any solutes dissolved in the solvent into the collection tank; installing the cartridge packed with plant stock into the can and connecting the solvent distribution pipe of the cartridge to the solvent reservoir; forcing solvent through the solvent distribution pipe , through the plant stock, to extract solvent compounds of interest from the plant stock and pass the solvent and extracted solute compounds into the collection tank; separating the solvent from the extracted solute compounds to recover the extracted solvent compounds of interest .

2. The method of claim 1 wherein: the solvent comprises ethanol, butane, propane, ethane, isopropyl alcohol, heptane, hexane, or ethyl acetate, preferably cooled to cryogenic temperature of about -80 °C.

3. The method of claim 1 further comprising the step of: forcing a flushing fluid through the solvent distribution pipe, through the plant stock and through perforations in the wall of the basket.

4. The method of claim 3 wherein: the flushing fluid comprises nitrogen gas.

5. The method of claim 1 further comprising the step of: freeze-drying the plant stock at the first location, either before or after packing the small particles of plant stock into the basket of the cartridge.

6. The method of claim 1 further comprising the step of: injecting bubbles into the solvent at a point in a solvent flow path prior to the plant stock and/or in the annular space between the solvent distribution pipe 9 and the perforated basket.

7. The method of claim 6 wherein: the bubbles comprise an inert gas or a solvent gas.

8. A cartridge and can assembly for use in a system for extracting soluble compounds from plant stock, said system comprising : a perforated basket 2 within a can 3 , said can configured to contain liquid solvent containing solutes from the plant stock, said perforated basket configured to retain plant stock within the basket and allow passage of the liquid solvent containing solutes through perforations in a wall of the basket , said basket having an inlet opening configured to allow packing of plant stock into the basket ; a solvent distribution pipe 9 disposed within the basket, said supply pipe having an inlet for connection to a solvent supply line ; said can having an outlet port for connection to a collection tank; a detachable closure configured for sealing and unsealing the inlet opening of the basket .

9 . A system for extracting soluble compounds from plant stock, said system comprising : a cartridge and can assembly for holding plant stock and passing solvent through the plant stock; a solvent reservoir containing a solvent suitable to dissolving good stuf f from the plant stock to create a solution containing the solvent and solutes extracted from the plant stock; a flushing fluid reservoir containing a flushing fluid that is non-reactive with the plant stock; and a collection tank for storage of solvent and solute ; wherein the cartridge and can assembly comprises : a perforated basket within a can, said can configured to contain liquid solvent containing solutes from the plant stock, said perforated basket configured to retain plant stock within the basket and allow passage of the liquid solvent containing solutes through perforations in a wall of the basket , said basket having an inlet opening configured to allow packing of plant stock into the basket ; a solvent distribution pipe disposed within the basket , said solvent distribution pipe having an inlet for fluid communication with a solvent reservoir and the flushing fluid reservoir ; said can having an outlet port for connection to a collection tank; means for selectively connecting the solvent distribution pipe with the solvent reservoir and the flushing fluid reservoir ; and means for forcing solvent through the basket and any plant stock within the basket ; and means for forcing flushing fluid through the basket and any plant stock within the basket .

10 . The system of claim 9 , further comprising : the means for selectively connecting the solvent distribution pipe comprises : a control valve communicating with the solvent distribution pipe, the solvent reservoir and the flushing fluid reservoir, said control valve having a first configuration placing the solvent reservoir in fluid communication with the solvent distribution pipe and having a second configuration placing the flushing fluid reservoir in fluid communication with the solvent distribution pipe .

11 . The system of claim 9 , wherein : the means for selectively connecting the solvent distribution pipe comprises : a control valve communicating with the solvent distribution pipe, the solvent reservoir and the flushing fluid reservoir, said control valve operable to supply a mix of flushing fluid and solvent simultaneously to the solvent distribution pipe .

12 . The system of claim 9 , further comprising : a gas inj ection system 21 configured to inj ect microbubbles , nano-bubbles , or both, into the solvent .

13 . A method for extracting soluble compounds from plant stock, said method comprising the steps of : milling plant stock at a first location to reduce the plant stock to small particles ; providing a cartridge and can assembly for use in a system for extracting soluble compounds from plant stock, said cartridge comprising : a perforated basket within a can, said can configured to contain liquid solvent containing solutes from the plant stock, said perforated basket configured to retain plant stock within the basket and allow passage of the liquid solvent containing solutes through perforations in a wall of the basket , said basket having an inlet opening configured to allow packing of plant stock into the basket ; a solvent distribution pipe disposed within the basket , said solvent distribution pipe having an inlet for connection to a solvent supply line and a flushing fluid line ; said can having an outlet port for connection to a collection tank; a detachable closure configured for sealing and unsealing the inlet opening of the basket ; packing the small particles of plant stock into the basket of the cartridge at the first location; optionally freeze-drying the plant stock at the first location, either before or after packing the small particles of plant stock into the basket of the cartridge ; transporting the cartridge and can assembly to an extraction system at a second location remote from the first location, and, at the second location : providing an extraction system for extracting soluble compounds from the plant stock packed in the basket, said system comprising : a solvent reservoir containing a solvent suitable to dissolving good stuf f from the plant stock to create a solution containing the solvent and solutes extracted from the plant stock; a flushing fluid reservoir containing a flushing fluid that is non-reactive with the plant stock; and a collection tank for storage of solvent and solute ; means for selectively connecting the solvent distribution pipe of the cartridge with the solvent reservoir and the flushing fluid reservoir to the solvent distribution pipe ; and means for forcing solvent and flushing fluid through the basket and any plant stock within the basket , and forcing solvent and any solutes dissolved in the solvent into the collection tank; installing the cartridge and can assembly packed with plant stock in the extraction system by connecting the supply pipe of the cartridge to the solvent reservoir and the flushing fluid reservoir, and connecting the outlet port to the collection tank; forcing solvent through the supply pipe, through the plant stock, to extract solvent compounds of interest from the plant stock and pass the solvent and extracted solute compounds into the collection tank; and forcing flushing fluid through the solvent distribution pipe , through the plant stock and through perforations in the wall of the basket ; and separating the solvent from the extracted solute compounds to recover the extracted solvent compounds of interest .

14 . A method of extracting compounds from plant stock, said method comprising : providing a system comprising : a solvent supply reservoir, said solvent being a liquid or gas ; a flushing fluid reservoir, said flushing fluid being a liquid or gas ; a perforated basket configured to hold plant stock, with perforations si zed to allow passage of the solvent and flushing fluid while inhibiting passage of solid undissolved plant mass ; at least one supply conduit configured for introducing solvent , flushing fluid, or both into the plant stock within the basket ; and a collection conduit in fluid communication with the basket, said collection conduit also in fluid communication with a collection tank; performing the steps of : inj ecting solvent into and through the plant stock, and passing the solvent to the collection tank, to extract solvents from the plant stock; and after inj ecting solvent into and through the plant stock, inj ecting flushing fluid into the plant stock and through perforations in the basket to clear the perforations of plant stock solids collected in the pores .

15. The method of claim 14, further comprising: injecting flushing fluid through the solvent distribution pipe and into the plant stock disposed in the basket, to cool the plant stock to a temperature colder than an initial temperature of the plant stock.

16. The method of claim 14, further comprising: injecting flushing fluid through the solvent distribution pipe and into the plant stock disposed in the basket, prior to an initial injection of solvent, to cool the plant stock to a temperature colder than an initial temperature of the plant stock.

17. The method of claim 14, further comprising: with the plant stock in a dry condition prior to a first injection of solvent, injecting flushing fluid through the solvent distribution pipe and into the plant stock disposed in the basket, to cool the plant stock to a temperature colder than an initial temperature of the plant stock.

18. The method of claim 14, wherein: the step of injecting solvent into the plant stock is accomplished by injecting solvent at various locations along a length of the basket.

19. The method of claim 1, wherein: the step of injecting solvent into the plant stock is accomplished by injecting solvent at various locations along a length of the basket.

20 . The method of claim 13 , wherein : the step of inj ecting solvent into the plant stock is accomplished by inj ecting solvent at various locations within the basket .

21 . The method of claim 14 , wherein : the step of inj ecting solvent into the plant stock is accomplished by inj ecting solvent at various locations within the basket .

22 . A cartridge for use in a system for extracting soluble compounds from plant stock, said system comprising : a perforated basket configured to fit within a can configured to contain liquid solvent containing solutes from the plant stock, said perforated basket configured to retain plant stock within the basket and allow passage of the liquid solvent containing solutes through perforations in a wall of the basket , said basket having an inlet opening configured to allow packing of plant stock into the basket ; a solvent distribution pipe disposed within the basket , said solvent distribution pipe having an inlet for connection to a solvent supply line and a flushing fluid line ; and a detachable closure configured for sealing and unsealing the inlet opening of the basket .