WO2021055886A1

WO2021055886A1 - Isolation of cannabinoids from aqueous-extracted phytocannabinoid precipitates

Info

Publication number: WO2021055886A1
Application number: PCT/US2020/051677
Authority: WO
Inventors: Mason LEGRANGE; William Lanier; Charles R. CIANCANELLI; Thomas GUEL; Lyle O'BRIEN
Original assignee: Beaker Intellectual, Llc
Priority date: 2019-09-20
Filing date: 2020-09-18
Publication date: 2021-03-25

Abstract

Economic methods scalable for commercial production are presented for the Isolation and purification of cannabinoids from precipitates generated by aqueous extraction of.cannabis from biomass or the transfer of acidic cannabinoids into an aqueous partition. The methods include steps for the isolation and purification of phytocannabinoids, other genera that produce cannabinoids naturally, and genetically modified organisms that are engineered for cannabinoid production from precipitate, generated from either an aqueous extraction of cannabis or from the transfer of acidic cannabinoids into an aqueous partition and include ecologically friendly process steps for isolation and purification of phytocannabinoids, other genera that produce cannabinoids naturally, and genetically modified organisms that are engineered for cannabinoid production from precipitate generated from either an aqueous extraction of cannabis or from the transfer of acidic cannabinoids into an aqueous partition employing solvent extraction and partitioning of the precipitate.

Description

ISOLATION OF CANNABINOIDS FROM AQUEOUS-EXTRACTED PHYTOCANNABINOID PRECIPITATES FIELD OF THE INVENTION

[0001] The present invention relates generally to the extraction and isolation of natural products from plant materials. Specifically, the present invention relates to a method for the extraction of cannabinoid compounds from naturally occurring biosources and genetically modified organisms that are designed to produce cannabinoids. More specifically, the present invention relates to an ecologically safe and efficient method for the isolation and purification of cannabinoids from a precipitate produced by an aqueous extraction process via aqueous partition of acidic cannabinoids.

BACKGROUND OF THE INVENTION

[0002] The extraction, separation, and isolation of natural products from their host organisms, be they plants, animals or micro-organisms, is a technically challenging task. Over time, many natural products have been isolated and studied on a laboratory scale for use in food, pharmaceutical, and human and veterinary medical applications. However, extraction and isolation of these natural compounds from their host organisms even on a laboratory scale frequently requires the application of complex and sensitive processing techniques and the use of sophisticated and expensive equipment. Methods which have proven successful for isolating new compounds include techniques such as high-performance liquid chromatography, thin layer chromatography, centrifugal partition chromatography, nuclear magnetic resonance processes, and Fourier- transformed infrared spectroscopy, just to name a few. For example, as early as 1937, the U.S. Department of Commerce, National Bureau of Standards published the results of research into the extraction of different forms of cellulose from plant and algal biomass using a combination of acidic and caustic treatments. “Simplified Volumetric Determination of Alpha , Beta and Gamma Cellulose in Pulps and Papers, U.S. Department of Commerce, National Bureau of Standards, Research Paper RP979, Journal of Research of the National Bureau of Standards , Vo/.18, March, 1937. While useful for research purposes, the afore-mentioned and related exemplary systems and methods have not been scaled or optimized for commercial production. [0003] Most industrial scale plant extractions demand the use of large volumes of solvent, such as hydrocarbons and alcohols, or enormous supercritical COa systems. These systems and methods inherently introduce hazards and are encumbered by limitations revolving around the sheer volume of solvents required to extract the biomass at required output volumes. These limitations are enforced by both environmental and regulatory bodies with strict restrictions on solvent use and residual solvent treatment and disposal. Additionally, cleaner systems such as those using supercritical CO2 require a large footprint and operate under immense pressure, thus imposing their own dangers and limitations. Therefore, strong innovation and design incentives exist to remove, or to reduce, the amount of solvents required to extract natural products from their host organisms by environmentally friendly processes. One clear example of this is cannabis processing and, specifically, in the extraction of cannabis biomass and phytocannabinoids from hemp plants.

[0004] During the last half of the twentieth century, as an outgrowth of societal changes which began in the 1960's, concerns over climate change and an enhanced environmental awareness, interest has increased dramatically in the use of ecologically safe, naturally occurring and so-called "environmentally friendly" compounds and associated manufacturing practices in various applications. Among such applications, alternative forms of medicine which make use of natural products for the holistic treatment of various medical and psychological disorders are being investigated actively.

[0005] The hemp and marijuana genus (cannabis) is a source of natural products known as cannabinoids, now recognized as having beneficial medical and therapeutic applications. Cannabinoids are compounds naturally present in the plant that, depending on the specific cannabinoid, have psychoactive and therapeutic effects on certain medical conditions. Cannabis includes at least three recognized species: cannabis sativa, cannabis indica and cannabis ruderalis, which have been used in various forms since ancient times, including use in Asian herbal medications dating back to 2000 BC, as a food source (seeds), and in fiber production for textiles Clearly, cannabis is one of the more ancient and multifaceted cultivars of man to date. [0006] Of interest to the medical and scientific community, the cannabis sativa species contains high concentrations of several medically relevant cannabinoids, for example: cannabidiolic acid (CBDa), its decarboxylated derivative, cannabidiol (CBD), cannabigerolic acid (CBGa) and other phytocannabinoids. Despite its clear utility across multiple cultures, cannabis has received considerable negative publicity over time because of certain undesirable psychoactive compounds and trafficking that has resulted in the classification of the genera as contraband. Until recently, the illegality of its use on both the state and federal level has limited science and medical researchers’ ability to fully investigate cannabis’ utility. Recently, the non-psychoactive medicinal and therapeutic properties of the lesser publicized cannabinoids have begun to offer innovative therapies to the medical community in the treatment of chronic pain, inflammation, certain cancers, epilepsy, seizures, and infections. To this end, cannabinoids are currently poised to be a potential combatant against the current opioid epidemic and to provide an alternative to treatment options related to chronic ailments for which opiates and pharmaceutics are the current predominant course of action.

[0007] As noted above, the extraction of cannabinoids from the native plant is a complex and potentially hazardous process which requires the use of high-pressure supercritical carbon dioxide and/or highly flammable and toxic solvents such as benzene, ethanol, methanol or alcohol. The high solvent to biomass ratio, required for efficient extraction of cannabinoids leads to the presence of potentially hazardous amounts of solvents on site and in operation, which scales linearly as the desired volume of active molecules is increased, ultimately reaching levels that are regulatory and economically prohibitive. As the demand for cannabinoids increases so, too, does the demand for, a more efficient, environmentally friendly, extraction process to reduce or eliminate the quantity of solvents needed for biomass extraction. [0008] The extraction process is further complicated by the variations in composition content within each individual plant, which may differ significantly from one plant to another. Moreover, current extraction procedures may leave a number of different phytocannabinoids and other co-precipitates, protein complexes, and unhealthy waste by-products such as waxes, fats, and residual solvents in the extract or precipitate. Conventional processing methods incorporate a process known as "winterization' or alcohol washing to remove these by-products. An example of such prior art processes and cannabis extract formulations is disclosed in U.S. Patent No. 9,730,911 B2 issued on August 15, 2017, to Verzura et al. and entitled, “ Cannabis Extracts and Methods of Preparing and Using Same.” Winterization requires soaking the extract in alcohol and then freezing it to cryogenic temperatures for at least twenty- four hours to separate out the unwanted plant waxes and lipids. The winterization process may be repeated several times to achieve the desired purity of oil. However, each round of winterization is accompanied by an associated loss of cannabinoids, thus reducing the extract's overall effectiveness.

[0009] Cannabidiol (CBD), the decarboxylated form of the acidic cannabinoid CBDa, has been the subject of considerable historical research, and its efficacy in medicinal applications is well-established. Research on cannabinoids, outside of CBD and THC alone, is only now expanding with enhanced interest and receptivity in the medical and scientific communities. Decarboxylation of all acidic cannabinoids requires a specific amount of activation energy to perform the reaction. This is generally performed at temperatures between 120°C to 140°C for extended amounts of time, up to two and a half hours in some instances. Current extraction methods require this step to move through distillation for further purification. The efficiency of decarboxylation is in the approximate range of 70-85%, and economic processes are not presently available for the isolation and purification of water-extracted cannabinoids and other genera that produce cannabinoids naturally and genetically modified organisms that are engineered for cannabinoid production from precipitate generated from either an aqueous extraction of cannabis or from the transfer of acidic cannabinoids into an aqueous partition.

[0010] In view of the above, it will be apparent to those skilled in the art from this disclosure that a need exists for an improved, economical method for the isolation and purification of aqueous extracted cannabinoids from sediment, other contaminants that co-precipitate with cannabinoids in an aqueous medium, and/or other suspended particulate or biological matter, not excluding living organisms such as yeast or algae. The present invention addresses these needs in the art as well as other needs, all of which will become apparent to those skilled in the art from the accompanying disclosure. SUMMARY OF THE INVENTION

[0011] To address the needs in the art, in one aspect the present invention provides a method for the isolation and purification of cannabinoids from precipitates generated by aqueous extraction of cannabis from biomass or the transfer of acidic cannabinoids into an aqueous partition.

[0012] In another aspect of the present invention, a method is provided for the isolation and purification of phytocannabinoids, other genera that produce cannabinoids naturally, and genetically modified organisms that are engineered for cannabinoid production from precipitate generated from either an aqueous extraction of cannabis or from the transfer of acidic cannabinoids into an aqueous partition.

[0013] In still another aspect of the present invention, an economic and scalable method is provided for the isolation and purification of cannabinoids from sediment and contaminates that co-precipitate in an aqueous cannabis extraction, including but not limited to protein complexes, water-soluble cofactors, and alpha, beta and gamma forms of cellulose.

[0014] In yet another aspect of the present invention, an ecologically friendly method is provided for the isolation and purification of phytocannabinoids, other genera that produce cannabinoids naturally, and genetically modified organisms that are engineered for cannabinoid production from precipitate generated from either an aqueous extraction of cannabis or from the transfer of acidic cannabinoids into an aqueous partition employing solvent extraction and partitioning of the precipitate.

[0015] These and other features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of preferred embodiments taken in connection with the accompanying drawings and by reference to the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Referring now to the attached drawings which form a part of this original disclosure.

[0017] Fig. 1 is a flow diagram of the process of the present invention in accordance with an embodiment. [0018] Fig. 2 is a flow diagram of the process of the present invention in which an aqueous slurry or filtered aqueous solution containing cannabinoids is processed is processed in accordance with an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Selected embodiments of the present invention will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments of the method herein disclosed are provided for illustration purposes only and not to limit the invention as defined by the appended claims and their equivalents.

[0020] Referring now to Fig. 1, a flow diagram or chart is provided to illustrate the steps of a method for the isolation and purification of cannabinoids from precipitates generated by aqueous extraction of cannabis from biomass or the transfer of acidic cannabinoids into an aqueous partition in accordance with an embodiment of the present invention. Following the harvesting of a hemp plant, it may be formed into a cannabinoid rich biomass. The cannabinoid containing solids 5 at step A is in the form of a biomass slurry or a solid generated from genetically modified microbes.

[0021] Precipitate 5 from an aqueous extracted cannabis process is held in a storage tank, a holding vessel, or a suitably sized containment vessel 10 shown in step A. in Fig. 1. The precipitate may be also used directly without an intermediate storage step inasmuch as it is generated in an aqueous extraction process. The precipitate includes any material containing some portion of cannabinoids that was produced from cannabis sativa (hemp and marijuana alike), sediment and contaminates that coprecipitate in an aqueous cannabis extraction, including but not limited to protein complexes, water-soluble cofactors, and alpha, beta and gamma forms of cellulose as hereinabove described.

[0022] Optionally, as shown in Fig. 1, step A’, the precipitate material may be dried to produce a dehydrated precipitate 5' having a water content compatible with a selected solvent 15 for further processing, as will be described in greater detail below. The dehydration process may be carried out through, by example but not limited to, centrifugation, screw pressing, filtration, filter pressing, or heat drying in a suitable drying vessel 12 prior to introduction to the storage tank 10 or introduction to the solvent 15, which is held in a feed tank 18, step B. Preferably, the solvent is ethyl acetate; however, any material that is immiscible or slightly miscible with water (containing a mostly non-polar structure or ether-based solvent). Non-polar solvents include, but not limited to aliphatic hydrocarbons, alicyclic hydrocarbons, ether-based solvents, or ketone solvents, by way of example hexane, heptane, ethyl acetate, acetone, dimethyl ether, chloroform, or pentane may be used.

[0023] The aqueous precipitate is introduced to a reactor 25 at step C where it is mixed with the desired solvent to extract the cannabinoids in the suspended solids. The solvent may be introduced to the reactor either before or after the addition of the precipitate. The solvent temperature is controlled to fall in a range of approximately -50° C to approximately 80° C and is preferably in a range of approximately 15° C to approximately 25° C. The reactor is agitated with proper design for the appropriate classification area. By way of example, the reactor can be a jacketed vessel that consists of an agitated design, which allows for either cold or hot extraction of the material to gain certain extraction efficiencies or more selective removal of cannabinoids. It is understood that the equipment and processes of the present invention may be scaled up or sized for any level of operation without departing from the scope hereof. Regardless of size, the process may be monitored continuously for temperature, composition, pH and so forth as is known in the art.

[0024] In another embodiment, at step C, a continuous extraction system is used instead of the reactor or vessel 25 without departing from the scope of the present invention. By way of example but not of limitation, this step employs a counter flow system where fresh solvent is first introduced near a system s discharge and works its way towards an input aperture of or entrance to the system. In accordance with this embodiment, the least cannabinoid rich material is extracted most efficiently with fresh solvent and leaving behind the unextracted biomass with the richest saturated solvent. [0025] At Fig. 1, step D, solvent containing cannabinoid solids 30 extracted from the suspended solids at step C are transferred to a wash vessel or tank 32. Extraction or removal is performed through mechanical filtration or centrifugation; by way of example, but not of limitation, disk stack centrifuge, decanter centrifuge, microfiltration, bag filtration, filter press, membrane separation, or a combination thereof. This step is shown generally at 35 in Fig. 1. Solids or extracted aqueous precipitate 38 from the extraction step are properly disposed of per local regulation at step E or sent on for further processing. Certain molecular components of the discharged waste such as proteins, polysaccharides, or terpenes may be of value and may be segregated and retained for further processing.

[0026] The solvent containing cannabinoids and other soluble molecules 30, also known in the art as tincture or miscella, is sent to the vessel or reactor 32, where it undergoes a liquid-liquid washing step, immediately followed by phase separation, at Fig. 1, step H. However, other liquid-liquid washing techniques may be employed to introduce a large surface area, or intimate phase contact, for efficient molecular partitioning between the two liquids without departing from the scope of the present invention. Exemplary washing techniques include, but are not limited to, ultrasonic systems, counterflow liquid-liquid interface technologies, and high shear agitated reactors. Multiple liquid-liquid steps may be performed for more selective results. To name a few non-limiting examples, acidic washing, caustic washing, and brine washing may be applied sequentially as multiple liquid-liquid extraction steps. A caustic wash is used to neutralize any acidic nature of the solution to avoid adverse downstream effects. The pH of the caustic water is monitored and controlled at a level in the range of approximately 7.5 to approximately 10.5, and preferably in the range of 8.0 to 9.0. The pH of an acidic water wash is monitored and controlled at a level in the range of approximately 2.0 to approximately 6.5, and preferably in the range of 3.0 to 4.0. The water used in a liquid-liquid brine wash is monitored and controlled at a level in the range of approximately 1 ,000 ppm to approximately 20,000 ppm, and preferably in the range of 8,000 ppm to 11,000 ppm. Each wash is followed by a phase separation before the cannabinoid-containing solvent 30 is introduced to the next wash. This process will remove targeted undesirable contaminants that may reside in the cannabinoid solvent tincture or solution. The wash/phase separation step(s) may be performed in settling tanks, liquid-liquid disk stacks, liquid-liquid solid centrifuges, tricanters or other apparatus such as an evaporator which is described in more detail below, suitable for the process, identified generally at 40 in Fig. 1. [002h After liquid-liquid phase separation, the aqueous streams (reclamation and waste) are sent to waste or purified for reuse, step K. The purification and/or reclamation steps include reverse osmosis, resin filtration, oxidative breakdown of organics, solids filtration, or any combination thereof shown generally at 45 in Fig.1.

[0028] Following phase separation, the miscella is sent to an evaporation step,

Fig. 1, step I. In another embodiment, the solvent sent to chromatography at step L' via a compatible solvent system operatively connected into the process flow at the precipitate extraction step. The evaporator may consist of, but is not limited to, a falling film evaporator, rising film evaporator, thin film evaporator, rotary evaporator, or any combination thereof. The process is preferably carried out under vacuum to reduce the evaporator's skin temperature that is required to remove solvent from the cannabinoid tincture. The solvent is reclaimed and purified for reuse in the process. Cleaned crude cannabis oil 50 can then be diverted to chromatography, distillation, or other molecular purification systems, i.e. membrane partitioning. To comply with GMP or other internal protocol, the recovered solvent can be cleaned through selected resins to remove unwanted impurities at step J. Otherwise it is properly disposed of following local and federal regulations.

[0029] Cleaned cannabis crude oil 50 is sent to distillation step L for further purification, thereby producing a higher potency cannabinoid distillate 58. By way of example, but not limitation, the distillation step is performed by wiped film distillation, short path distillation, or fractional distillation processes, depicted generally at 52. The distillation pressure is monitored and controlled at a level in the range of approximately 1 millitorr to approximately ambient atmospheric pressure, and preferably in the range of 250 millitorr to 15,000 millitorr. The distillate could then move on to a chromatography process. In comparison with crude, the distillate provides a cleaner input, thereby resulting in more efficient operation of chromatography equipment. The chromatography system, shown generally at 55, may consist of centrifugal partition chromatography, simulated moving bed chromatography, flash chromatography, or any equivalent system.

[0030] Referring now to Fig. 1, at step L". following the evaporation step, step I, the cleaned cannabis crude or oil 50 is decarboxylated before entering into the distillation process, step L. Alternatively, the decarboxylated oil 51 may be sent directly to the chromatography step L'.

[0031] The distillate 58 is sent to a crystallization step, step M, for isolation of CBD or other crystalline forming cannabinoids. The distillate is introduced to a solvent or solvent system that is designed to crystallize target molecules out of the overall solution. This process may be performed through batch crystallization (i.e. jacketed/agitated reactors) or any continuous crystallization system (i.e. continuous flow jacketed tubes or the like) shown generally at 60.

[0032] Referring now to Fig. 1 , step N, the crystal slurry moves to a filtration or separation system. For example, Nutsche filter dryers, basket centrifuges, bag filters, filter presses, or other solids filtration techniques known in the art may be employed in this step without departing from the scope of the present invention. The solids are then dried to remove residual solvents down to the desired levels. The drying step may be performed using, by way of example, vacuum ovens, forced air operations, or continuous drying systems.

[0033] Although the desired product may be isolated cannabinoids 70, at step O. this process may be selectively stopped at any cannabinoid product output step following evaporation at step I without departing from the scope of the present invention. [0034] Referring now to Fig. 2, in accordance with an embodiment of the present invention, the steps of a method for the isolation and purification of cannabinoids from aqueous slurries or filtered aqueous solutions containing cannabinoids generated through aqueous extraction of cannabinoids from biomass or the transfer of acidic cannabinoids into an aqueous partition are shown. The cannabinoid containing slurry or solution 1 at step A may be selectively derived from a genetically modified microbial process without departing from the scope of the present invention.

[0035] Aqueous slurry or solution 1 is held in a storage tank, a holding vessel, or a suitably sized containment vessel 9 shown in step A. in Fig. 2. The solution 1 contains suspended solids or is filtered, thus removing the suspended solids; however, some portion of extracted cannabinoids remain suspended or dissolved in an aqueous mixture. Alternatively, the solution may be processed in accordance with step A' to remove any unwanted suspended solids 6 from the aqueous solution 1. This process may be carried out by any solid removal filtration process known in the art 5.

[0036] The aqueous solution 1 is introduced to an extraction system 20 at step C where it is mixed with the desired solvent to partition cannabinoids from the aqueous phase to the solvent phase. The solvent is introduced to the reactor either before or after the addition of the aqueous phase. The solvent temperature is selectively controlled to fall in a range of approximately -50° C to approximately 80° C and is preferably in a range of approximately 15° C to approximately 25° C. The reactor is agitated with proper design for the appropriate classification area. By way of example, the reactor can be a jacketed vessel that consists of an agitated design, which allows for either cold or hot extraction of the material to gain certain extraction efficiencies or more selective removal of cannabinoids. It is understood that the equipment and processes of the present invention may be scaled up or sized for any level of operation without departing from the scope hereof. Regardless of size, the process may be monitored continuously for temperature, composition, pH and so forth.

[0037] In another embodiment, at step C, the reactor is replaced by a continuous extraction system without departing from the scope of the present invention. By way of example but not of limitation, an exemplary continuous extraction system is in the form of a counter flow system where fresh solvent flows in one direction while the cannabinoid rich aqueous solution flows in the opposite direction whereby cannabinoid poor material is effectively and efficiently extracted, leaving fresh solvent and the unextracted cannabinoid solution containing the most saturated solvent, as hereinabove described. After a predetermined extraction time has been achieved, the two liquid phases are separated via mechanical or gravitational separation. The aqueous stream has now been relieved of the desired cannabinoids and moves on to step E. The solvent stream moves on to step D for further refinement.

[0038] In yet another embodiment, at step C an acid or base 18 is introduced to further promote partitioning of cannabinoids into the solvent phase. By way of example but not limitation, an acid may be introduced to drive the cannabinoids, especially dissolved acidic cannabinoids, out of the aqueous phase and into the solvent phase. [0039] Now referring to Fig. 2 step D, the saturated solvent 21. also known in the art as tincture or miscella, is sent to the vessel or reactor 25, where it undergoes further liquid-liquid washing steps, which are immediately followed by phase separation. However, other liquid-liquid washing techniques may be employed to induce intimate phase contact, for efficient molecular partitioning between the two liquids without departing from the scope of the present invention. Exemplary technology includes, but not limited to, ultrasonic systems, counterflow liquid-liquid interface technologies, and high shear agitated reactors. Multiple liquid-liquid steps may be performed selectively for more selective results. To name a few non-limiting examples, acidic washing, caustic washing, and brine washing may be applied sequentially as multiple liquid-liquid extraction steps. A caustic wash is used to neutralize any acidic nature of the solution to avoid adverse downstream effects. The pH of the caustic water is monitored and controlled at a level in the range of approximately 7.5 to approximately 10.5, and preferably in the range of 8.0 to 9.0. The pH of an acidic water wash is monitored and controlled at a level in the range of approximately 2.0 to approximately 6.5, and preferably in the range of 3.0 to 4.0. The water used in a liquid-liquid brine wash is monitored and controlled at a level in the range of approximately 1,000 ppm to approximately 20,000 ppm, and preferably in the range of 8,000 ppm to 11,000 ppm. Each wash is followed by a phase separation before the cannabinoid-containing solvent 30 is introduced to the next wash. This process removes targeted undesirable contaminants residing in the cannabinoid solvent tincture or solution. The wash/phase separation step(s) are be performed in settling tanks, liquid-liquid disk stacks, liquid- liquid solid centrifuges, tricanters or other apparatus suitable for the process, identified generally at 30 in Fig. 2.

[0040] After liquid-liquid phase separation, the aqueous streams (reclamation and waste) are sent to waste or purified for reuse, step E. The purification and/or reclamation steps include reverse osmosis, resin filtration, oxidative breakdown of organics, solids filtration, or any combination thereof shown generally at 35 in Fig.2.

[0041] Following phase separation, the miscella is sent to an evaporation step F.

In an embodiment, the solvent is transferred to chromatography at step H' if a compatible solvent is introduced at extraction step C. The evaporator is selected from commercially available equipment, such equipment including a falling film evaporator, rising film evaporator, thin film evaporator, rotary evaporator, or any combination thereof. The process is preferably carried out under vacuum to reduce the evaporator’s skin temperature that is required to remove solvent from the cannabinoid tincture. The solvent is reclaimed and purified for reuse in the process. Cleaned crude cannabis oil 40 is diverted to chromatography, distillation, or other molecular purification systems, i.e. membrane partitioning. To comply with GMP or other internal protocol, the recovered solvent is then cleaned through selected resins to remove unwanted impurities at step G. Otherwise it is properly disposed of following local and federal regulations.

[0042] Cleaned cannabis crude oil 40 is sent to distillation step H for further purification, arriving at a higher potency cannabinoid distillate 55. By way of example, but not limitation, the distillation is performed by wiped film distillation, short path distillation, or fractional distillation processes, depicted generally at 51. The distillation pressure is monitored and controlled in a range of approximately 1 millitorr to approximately ambient atmospheric pressure, and preferably in the range of 250 millitorr to 15,000 millitorr. The distillate is then transferred to a chromatography process. Distillate provides a cleaner input over crude, resulting in more efficient operation of chromatography equipment. The chromatography system, shown generally at 55, includes centrifugal partition chromatography, simulated moving bed chromatography, flash chromatography, or any equivalent system thereof.

[0043] Referring now to Fig. 2, at step H", following the evaporation step F, the cleaned cannabis crude 40 is decarboxylated before entering into the distillation process, step H. In an embodiment, the decarboxylated oil 50 is optionally sent directly to the chromatography step H'.

[0044] Thereafter, the distillate 55 is sent to a crystallization step, step I, for isolation of CBD or other crystalline forming cannabinoids. The distillate is introduced to a solvent or solvent system that is designed to crystallize target molecules out of the overall solution. This process may be performed through batch crystallization (i.e. jacketed/agitated reactors) or any continuous crystallization system (i.e. continuous flow jacketed tubes or the like) shown generally at 60. [0045] Referring now to Fig. 2, step J, the crystal slurry moves to a filtration or separation system. For example, Nutsche filter dryers, basket centrifuges, bag filters, filter presses, or other solids filtration techniques known in the art may be employed in this step without departing from the scope of the present invention. The solids are then dried to remove residual solvents down to the desired levels. The drying step is performed using, by way of example, vacuum ovens, forced air operations, or continuous drying systems. Although the desired product may be isolated cannabinoids 65, as shown at step K, the process may be selectively stopped at the point of production of any selected cannabinoid product following evaporation at step F without departing from the scope of the present invention.

EXAMPLES

Example 1 : Ethyl Acetate Extraction on Precipitant: a. Split out 250 mL of extract water, precipitated to pH 1.98. b. Split into five 50 mL centrifuge tubes and centrifuge for ten minutes - decant off supernatant. c. Add 5 mL of ethyl acetate to precipitant in each tube, vortex ten minutes, centrifuge ten minutes, and decant (approximately 24 mL wet, approximately 18 mL dry). d. Repeat step c and decant into separate container (~24 mL wet, ~18 mL dry). e. Vortex 5 mL of distilled water with remaining precipitant in 1 viral sample for high-performance liquid chromatography (HPLC) testing.

ANALYSIS: Most (over 90^%) of the CBDa in the precipitant was removed in the first ethyl acetate wash. The liquid extraction was also far cleaner, with the aqueous and ethyl acetate layers separating cleanly and most of the plant waste remaining in the aqueous layer.

Example 2: Salting Out Experiments: a. Two 250 mL batches extract water were precipitated to pH 2.0 (HCI). b. Decanted into two sets of five Falcon tubes, centrifuged and decanted. c. 5 mL of ethyl acetate were added to each tube, vortexed ten minutes, centrifuged ten minutes, and decanted (each set of five decants kept separate). d. The first batch of decant was evaporated until oil remained, then dissolved into saturated NaOH and NaCI aqueous solution; filtered off crystals that formed with 0.22 micron filter. e. The second batch of decant was evaporated until oil remained; then dissolved into saturated KOH and KCI; left to crystalize.

ANALYSIS: Salting did not produce a good degree of separation. Equal amounts of CBDa were found in the solution and the salt crystals.

Example 3: Bulk Extraction:

Batch 1 /Batch 2 (same procedure for both) a. -130 grams of hemp measured, three approximately 3 gram samples were taken for testing. b. Wash hemp (remaining 120 grams) in 4,000 mL pH 3.0 (HCI) distilled H2O at 50°C for 15 minutes; strain hemp out of wash. c. Extract hemp in 4,000 mL distilled water at pH 9.6 (NaOH) at 76°C and then strain again. d. Filter basic extract water in Buchner funnel and refrigerate filtered extract. BULK EXTRACT RESULTS:

Batch 1

Hemp potency: 11.092 grams total (approximately 9.3% potency)

Extraction efficiency: 76 / off plant into water Batch 2

Hemp potency 11.191 grams total (-9.23/ potency)

Extraction efficiency: 76% off plant into water Ethvl Acetate Extraction: a. Poured 250 mL sample of extract water, precipitated to pH 2.0, centrifuged and decanted in 5 Falcon tubes. b. Add 5 mL ethyl acetate to each tube, vortexed 10 minutes, centrifuged 10 minutes, decanted and dried the ethyl acetate with sodium sulfate. c. Repeated step b. d. Precipitated H2O: 0.002 grams CBDa (0.3%). e. Ethyl wash 1: 0.451 grams CBDa (68.4%). f. Ethyl wash 2: 0.129 grams CBDa (19.6%). g. Precipitant post wash: 0.077 grams CBDa 11.7% remaining, thus producing a 88.3 extraction efficiency from precipitant.

Additional Ethvl Acetate Extractions: a. 5 bulk aqueous extraction batches (5 gallons each) were conducted; precipitant was then centrifuged and decanted b. Ethyl acetate was added in a 3:1 ratio of ethyl acetate to precipitant; vortexed for 10 minutes; centrifuged for 10 minutes; followed by decanting of ethyl acetate. c. Repeated step b, but in 1:1 ratio; decanted ethyl acetate was combined prior to downstream processing.

Example 4: Liquid-Liquid Washes

Sodium Bicarbonate and Brine Washes (used ethvl acetate extract): a. Produced 400 mL of 17 sodium bicarbonate by mass by dissolving four grams sodium bicarbonate into ~40 mL distilled water. b. Measured pH of sodium bicarbonate solution: 8.16.

Trial 1: a. In 50 mL tube, added 25 mL of ethyl acetate and 25 mL sodium bicarbonate solution (Na HCO3); agitate by hand for 10 minutes. b. Centrifuge for 10 minutes, decant aqueous layer. c. Measured aqueous layer pH: 8.13. d. Observation - aqueous layer turned dark brown. e. Added 25 mL NaCI solution (prepared for trial 2). f. Repeat agitation and centrifuged steps. g. Measured aqueous layer pH: 6.72. h. Observation - aqueous layer remained clear.

Trial 2: a. Produced 10% NaCI solution (by mass) by adding 40 g NaCI to approximately 360 mL distilled H2O. b. Measured initial solution pH 6.26. c Added 25 mL ethyl acetate and 25 mL 10% NaCI solution; agitated for 10 minutes; centrifuged 10 minutes; then decanted aqueous layer. d. Measured aqueous layer pH: 3.45. e. Observation - aqueous layer clear. f. Repeated step c with fresh NaCI solution. g. Measured aqueous layer pH: 3.65.aqueous layer clear ANALYSIS: An NaCI wash alone does not significantly decrease the HCI in the ethyl acetate. However, a single NaHCO₃ wash effectively removes the HCI and does not change the pH significantly as it acts as a buffer. NaCI also does not remove pigment, whereas NaHCO₃ does. The only drawback is that ethyl acetate and aqueous NaHCO₃ do not readily separate. Accordingly, centrifugation is required. An NaCI wash readily separates. Recommended course of action: NaHCO₃ wash followed by centrifugation; followed by an NaCI wash and then allowing the two phases to separate.

Example 5: Liquid-Liquid Washes

Bulk NaHCO₃ Wash: a. NaHCO₃ 1% aqueous produced with pH 8.15, wash ethyl acetate 1:1 ratio. b. Measured post wash pH: 8.38. c. Observation - wash was very dark colored. d. NaHCO₃ 10% aqueous produced with pH 6.12, wash ethyl acetate 1:1 ratio. e. Measured post wash pH: 6.75. f. Observation - wash was clear.

NaHCO₃ Sequential Wash Trials (3x): a. 25 mL of ethyl acetate extract, add 25 mL of pH 8.13 NaHCO₃ in 50 mL tube; extract for 10 minutes via shaking; centrifuge 10 minutes; decant aqueous extract and wash (pH of wash: 8.09). b. Repeat step a with added fresh 25 mL NaHCO₃ solution pH 8.21 (partial pH: 8.24). c. Repeat step a. a third time with NaHCO₃ solution pH 8.21 (post pH: 8.29). ANALYSIS: Visually, the first wash is very dark and contains a large amount of pigment leaving a dark brown tint. The second wash only has a small light brown tint, with the third wash being even lighter. This indicates one wash should be sufficient to remove most pigments. The wash pulls a negligible amount of cannabinoids from the ethyl acetate, so a wash is recommended.

[0046] In view of the foregoing, the isolation and purification process of the present invention demonstrates its ability to yield cannabinoid extracts of high purity successfully and efficiently. While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for limiting the invention as defined by the appended claims and their equivalents.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A method for the isolation and purification of cannabinoids from precipitate and suspended solids present in an aqueous solution comprising the steps of: a. Capturing the precipitate and suspended solids; b. Separating precipitate and suspended solids operatively connected to cannabinoids in the aqueous solution; c. Introducing the precipitate and suspended solids from steps a. and b. into an extraction apparatus; d. Introducing one or more solvents into the extraction apparatus; e. Extracting the precipitate and suspended solids by agitating the one or more solvents, precipitate and suspended solids in the extraction equipment for a predetermined period of time; f. Separating the precipitate and suspended solids from the one or more solvents; g. Discharging the precipitate and suspended solids for further processing or waste remediation; h. Collecting the filtrate (or miscella) in a vessel; i. Performing a liquid-liquid wash on the collected filtrate with an aqueous solution whereby impurities remaining in the collected filtrate are removed; j. Separating immiscible liquids remaining in the collected filtrate after the liquid-liquid wash; k. Evaporating the one or more solvents, whereby crude cannabinoid oil residual is produced; and l. Processing the crude cannabinoid oil residual produced in step k.

2. The method of claim 1 wherein the aqueous solution includes cannabinoid bearing solids generated from an aqueous-based cannabinoid extraction process.

3. The method of claim 1 wherein the aqueous solution includes cannabinoid bearing solids made up of cells or particulate generated from the growth of microbiological organisms adapted to produce cannabinoids.

4. The method of claim 1 wherein the aqueous solution includes cannabinoid bearing solids generated through the extraction and precipitation of acidic cannabinoids partitioned to an aqueous phase from one or more solvent miscella.

5. The method of claim 4 wherein the one or more solvent miscella are generated from upstream extraction of cannabinoid containing biomass or feedstock with solvent.

6. The method of claim 5 wherein the one or more solvents are chosen from one or more of the following: aliphatic hydrocarbons, alicyclic hydrocarbons, ether- based solvents, and polar aprotic solvents.

7. The method of claim 1 further including the step of dewatering/drying of the precipitate and suspended solids captured at step a.;

8. The method of claim 1 wherein the step of separating the precipitate and suspended solids is performed in a continuous filtration system.

9. The method of claim 1 wherein the separation of precipitate and suspended solids occurs in a basket or decanter centrifuge.

10. The method of Claim 1 wherein the separation of precipitate and suspended solids occurs in an inline filter or Nutsche filter.

1 i.The method of claim 1 wherein the extraction apparatus at step b. comprises a batch or semi-batch vessel.

12. The method of claim 1 wherein the extraction apparatus at step b. comprises a continuous flow system.

13. The method of claim 12 wherein the continuous flow system includes a countercurrent flow extraction system.

14. The method of claim 1 wherein the predetermined period of time in step d. is in a range of 3 minutes to 60 minutes.

15. The method of claim 1 wherein the step of further processing of discharged solids at step g. includes the step of identifying and segregating selected molecules including proteins, polysaccharides, and terpenes.

16. The method of claim 1 wherein the liquid-liquid wash at step i. occurs in a continuous liquid-liquid extraction system.

17. The method of claim 1 wherein the liquid-liquid wash at step i. occurs in an agitated vessel.

18. The method of claim 1 wherein the aqueous solution at step i. has a preselected pH.

19. The method of claim 18 wherein the pH of the aqueous solution in the liquid- liquid wash at step i. is selected in response to solubility profiles of the aqueous solution and the collected filtrate.

20. The method of claim 1 further including one or more additional liquid-liquid washes at step h. to eliminate a broader range of impurities.

21. The method of claim 20 wherein each of the one or more additional liquid-liquid washes have pH adapted to enhance the removal of impurities in the collected filtrate.

22. The method of claim 1 wherein one or more solvents having preselected polarities are introduced to provide a gradient the cannabinoids can follow from a polar solvent into a more non-polar solvent.

23. The method of claim 1 wherein the step of evaporating the one or more solvents further includes the step of membrane partitioning.

24. The method of claim 1 wherein the step of processing crude cannabis oil residual at step k. further includes the step of decarboxylation.

25. The method of claim 1 wherein the step of processing of crude cannabis oil residual at step k. further includes the step of distillation.

26. The method of claim 1 wherein the step of processing of crude cannabis oil residual at step k. further includes a chromatography step adapted to produce isolated cannabinoids or analogues thereof.

27. The method of claim 25 further including the step of crystalizing the distillate to obtain isolated cannabinoids.

28. The method of claim 1 wherein the crude cannabinoid oil residual comprises an isolate or matrix of CBNA, CBDA, CBGA, CBCA, THCA, CBLA, any decarboxylated form thereof, or cannabinoid and analogues containing a C1-10 carbon chain.

29. The method of claim 1 wherein the separation of liquid phases in step j. further includes the step of gravitational separation of the liquid phases.

30. The method of claim 1 wherein the step of separating the immiscible liquid phases in step j. is performed in a liquid-liquid centrifuge.

31.The method of claim 30 wherein the liquid-liquid centrifuge is a disk stack centrifuge.

32. The method of claim 1 further including the step of controlling temperature throughout the individual steps of the method whereby a crude cannabinoid oil residual having a preselected purification level is produced.

33. A method for extraction or purification of cannabinoids from an aqueous solution by partitioning cannabinoid(s) or impurity(s) suspended therein into selected liquid phases, the method comprising the steps of a. Introducing an aqueous solution containing cannabinoids preselected quantities of suspended particulate into an extraction system; b. Introducing one or more solvents into the aqueous solution; c. Performing a liquid-liquid extraction/partition on the aqueous solution whereby the cannabinoids contained therein are purified; d. Separating immiscible liquid phases remaining in the aqueous solution following the liquid-liquid partition step; e. Evaporating one or more of the solvents, whereby crude cannabinoid oil residual is produced; and f. Processing of the crude cannabinoid oil residual.

34. The method of claim 33 wherein the aqueous solution is a filtrate generated by performing the method of claim 1.

35. The method of claim 33 wherein the step of partitioning further includes the step of adjusting the pH of the aqueous solution in the presence of a partially miscible or immiscible solvent.

36. The method of claim 33 wherein cannabinoids from the aqueous cannabinoid solution are extracted/partitioned into a partially miscible or immiscible solvent.

37. The method of claim 33 including the step of further purifying the cannabinoids in the aqueous phase by extracting or partitioning impurities from the aqueous cannabinoid solution into a partially miscible or immiscible solvent.

38. The method of claim 33 further including the step of touching adapted to drive the cannabinoids from the aqueous solution into a more non-polar solvent.

39. The method of claim 33 further including the step of introducing one or more solvents of varying polarity are introduce to provide a gradient the cannabinoids can follow from a polar solvent into a more non-polar solvent.

40. The method of claim 33 wherein the process is carried out in a continuous manner.

41.The method of claim 40 wherein the process is carried out in a counterflow system.

42. The method of claim 33 wherein the process is carried out in a batch or semibatch extraction system;

43. The method of claim 33 that includes multiple liquid-liquid extraction/partition steps at step c.

44. The method of claim 33 further including the step of adjusting the pH of the aqueous solution at step c. via the addition of an acid or a base.

45. The method of claim 33 wherein the pH at step c. is adjusted to drive the cannabinoids into the solvent phase;

46. The method of claim 45 wherein the pH at step c. is adjusted to drive impurities from the aqueous solution into the solvent phase.

47. The method of claim 45 wherein the pH at step c. is selected to attract specific impurities away from the cannabinoids.