WO2022192793A1

WO2022192793A1 - Solvent limited isolation of crystalline cannabinoids

Info

Publication number: WO2022192793A1
Application number: PCT/US2022/020238
Authority: WO
Inventors: Thomas SMELZTER; Sean Colvin; Robert Davis; Jacob Black
Original assignee: Treehouse Biosciences, Inc.
Priority date: 2021-03-12
Filing date: 2022-03-14
Publication date: 2022-09-15

Abstract

Systems and methods to isolate relatively pure isolated cannabinoids include heating a starting hemp material to form a heated liquid, adding a catalyst, and cooling the heated liquid. Catalysts include relatively pure seed cannabinoid crystals, such as above 95% pure CBD, CBG, and CBN crystals. The precipitate formed during cooling the heated liquid may be treated one or more times by heating, adding catalyst, and cooling to form another precipitate.

Description

Solvent Limited Isolation of Crystalline Cannabinoids

Background

[0001] Cannabidiol (“CBD”), Cannabigerol (“CBG”), and Cannabinol (“CBN”) are some of the many non-psychoactive cannabinoids naturally produced in a variety of strains of Cannabis sativa L. (“cannabis plant” or “cannabis”). These cannabinoids are noted for their potential pharmacological, medicinal, and therapeutic benefits. For example, initial research indicates that CBG may be effective in reducing intraocular pressure, reducing tissue inflammation, inhibiting bacterial growth, and blocking cancer related intracellular growth receptors. Further, preliminary studies indicate that CBN may be a useful sleep aid. To further study and understand the potential benefits of the various cannabinoids found in cannabis, access to a relatively pure or isolated forms of these cannabinoids is desirous.

[0002] Solvent-based crystallization and recrystallization techniques produce relatively pure forms of isolated cannabinoids. The technology, however, remains limited for certain applications. For example, solvent-based crystallization suffers from the need to use volatile, hazardous, and expensive liquid solvents.

[0003] Typical solvent-based crystallization techniques involve the use of one or more hazardous hydrocarbon solvents, which is used to purify crystalline cannabinoids via precipitation, crystallization or re-crystallization. Further, expensive storage, solvent recovery systems, and vapor off-take systems are often employed to mitigate the risk of combustible solvents, such as propane or butane. Additionally, commonly used liquid solvents often present health risks. Hexane, a commonly used solvent, has very strict limitations on residual solvent limits in final products due to its potent neurotoxicity.

[0004] To mitigate health risks, manufactures often wash resulting crystals or use other techniques to remove these solvents from the resulting crystals. These techniques, however, often leave detectable amounts of the solvent behind.

[0005] To mitigate production hazards associated with hydrocarbon solvents, specialized and expensive equipment is often employed. Effort and expense are put toward engineering systems to limit and contain the formation of vapors and gases, limit ignition sources, and facilitate waste removal and treatment. Such efforts, however, are generally be balanced against the need of providing higher pressures and temperatures typically used for solvent-based crystallization. The result is large, inefficient vessels and machinery.

[0006] While these efforts may function to produce cannabinoid crystals, these crystals are typically limited by certain regulatory and market issues in applications. For example, typical solvent-based crystallization methods disqualify the resulting crystals from USDA organic classification. Further, consumers of cannabinoid isolate often refuse crystals produced using harsh solvents, and further demand very small residual solvent levels.

[0007] Thus, it remains desirous to devise technology to form relatively pure crystalline isolate cannabinoids that is more economical, safer, has lower energy consumption, and meets regulatory standards and market demand.

[0008] It is with respect to these and other considerations that the technology is disclosed. Also, although relatively specific problems have been discussed, it should be understood that the embodiments presented should not be limited to solving the specific problems identified in the introduction.

Summary

[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key factors or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0010] The technology described herein includes systems and methods to isolate relatively pure isolated cannabinoids include heating a starting hemp material to form a heated liquid, adding a catalyst, and cooling the heated liquid. Catalysts include relatively pure seed cannabinoid crystals, such as above 95% pure CBD, CBG, and CBN crystals. The precipitate formed during cooling the heated liquid may be treated one or more times by heating, adding catalyst, and cooling to form another precipitate.

[0011] For example, the technology includes a method for isolating crystalline cannabinoids. In aspects of the technology, the method comprising: providing a remediated distillate, wherein the remediated distillate is at least partially a solid; heating the remediated distillate to a temperature range to form a substantially melted solution; adding a catalyst to the substantially melted solution to form a mixture; cooling the mixture to a temperature so that at least one compound precipitates out of the mixture as a solid to form the at least one compound and a remainder solution; and collecting the at least one compound. In some aspects, the temperature is between about 40 °C and about 55 °C. Further, collecting the at least one compound may include: drawing off the remainder solution from the at least one compound by filtering the solution in the presence of a purge gas. The purge gas may be one of air, argon, nitrogen, and any combination thereof. The method may also include a a purify operation after the collecting the at least one compound operation. That purify operation may include providing the at least one compound.

The at least one compound may be at least partially a solid. The purify operation may also include heating the at least one compound to a temperature range to form a second substantially melted solution, adding a catalyst to the second substantially melted solution to form a second mixture, cooling the second mixture to a temperature so that at least one purified compound precipitates out of the mixture as a solid to form the at least one purified compound and a remainder solution, and collecting the at least one purified compound. In some aspects, the purify operation is performed at least one additional time on the at least one purified compound. [0012] The catalyst used in the technology described herein may be a cannabinoid isolate in crystalline form. That cannabinoid isolate may be selected from the group consisting of cannabidiol and cannabigerol.

[0013] The cooling of the mixture operation comprises cooling the mixture at rate of about 1° C per 24 hours for a period of about 4 to about 7 days. The method may include agitating the mixture.

[0014] Filtering may occur by passing the mixture through a filter having a restriction of no greater than 200 micrometers.

[0015] The innovative technology also includes a system for isolating crystalline cannabinoids.

In aspects of the technology, the system comprises a pre-treatment chamber in fluidic communication, via a transfer conduit, with a crystallization chamber having at least one inner wall and at least one outer wall, wherein the transfer conduit includes a filter mechanism. The system may have a starting material disposed within the pre-treatment chamber. The pre treatment chamber may also include being in thermal communication with a heating element that is capable of directing heat to the starting material. In some aspects, the system may also include the at least one outer wall of the crystallization chamber being coupled to a thermal regulating jacket. [0016] In some aspects of the technology, the filter mechanism of the transfer conduit comprises a mesh screen.

[0017] The transfer conduit may comprise a first pipe having a pre-treatment end and a filter end. The pre-treatment end being coupled to the pre-treatment chamber and the filter end being coupled to the filter mechanism. The transfer conduit may also comprise a second pipe having a filtered end and a crystallization end, wherein the filtered end is coupled to the filter mechanism and the crystallization end is coupled to the crystallization chamber.

[0018] In some aspects of the technology, the crystallization chamber may include an agitator. The agitator may comprise a paddle disposed within the volume, and the pre-treatment chamber may include an inner pre-treatment wall defining a volume.

Detailed Description

[0019] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in the description of the embodiments of the disclosure and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Also, as used herein, “and/or” refers to and encompasses any and all possible combinations of one or more of the associated listed items. Furthermore, the term “about,” as used herein when referring to a measurable value such as an amount of a compound, amount, dose, time, temperature, and the like, is meant to encompass variations of 20%, 10%, 5%, 1%, 0.5%, or even 0.1% of the specified amount. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Unless otherwise defined, all terms, including technical and scientific terms used in the description, have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0020] Fig. 1 illustrates an example system 100 for practicing aspects of the innovative technology described herein. As illustrated, system 100 includes pre-treatment chamber 102 in fluidic communication with crystallization chamber 112. In the example illustrated, fluidic communication is achieved through a flow conduit 110. [0021] In examples, pre-treatment chamber 102 may be sized and shape to receive hemp starting material 106. Starting hemp material 106 may be a solid or semi-solid mixture comprising one or more cannabinoids. In some examples, CBN, CBD, and/or CBG may be present in greater than sixty-five percent (65%) by weight relative to the other materials in the starting material 106. For certain applications, having CBN, CBD, and/or CBG in greater than sixty-five (65%) aids in the crystallization of the one or more cannabinoids using the technology described herein.

[0022] Heating element 104 heats starting hemp material 106. Heating element 104 may be any suitable means to transfer heat to starting material 106 including applying heat directly to the chamber via flame, electrical induction, liquid heating jacket, circulating a heated gas through and into the pre-treatment chamber and the like. The heating element may be controlled to cause the starting hemp material to increase to a temperature to about the melting temperature of the starting hemp material. In examples, the melting temperature of the starting hemp material is about 52 °C, about 54 °C, about 56 °C, about 58 °C, about 60 °C, about 62 °C, about 64 °C, about 66 °C, about 68 °C, about 70 °C, and about 72 °C. It will be appreciated that the melting temperature is the temperature at which substantially all the starting hemp material turns to liquid, with the understanding that some solids or other inclusions may remain in the liquid. In examples, the heating element applies heat to the pre-treatment chamber 102 and/or the starting hemp material 106 to heat and maintain the heating element to about the starting hemp material melting temperature or suitable ranger thereof.

[0023] In examples, application of heat through the heating element 104 causes the starting hemp material 106 to substantially melt to form a liquid. In examples, the liquid has the viscosity of between 20 and 40 cP at 40 °C. The substantially melted liquid comprises, in examples, a mixture of cannabinoids, oils, terpenes, and fatty acids along with other material. The liquid may then be transferred to the crystallization chamber 112 for further processing.

[0024] As illustrated, transfer occurs through transfer conduit 110. Transfer conduit may be a pipe, an open channel, or other apparatus capable of directing the substantially melted liquid into the crystallization chamber 112. In aspects of the technology, the transfer conduit 110 may be heated to maintain the temperature of the substantially melted liquid at or around a temperature range, such as the melting temperature described above. Further, for certain applications, it is desirable to have the transfer conduit 110 a material such as metal, plastic, PTFE, and the like. [0025] One or more material separators 108 may be disposed within the transfer conduit 110. A material separator 108 may be used to fdter at least a portion of residual solid materials and/or semi-solid materials from the substantially melted liquid prior to entering the crystallization chamber. The solid material may be plant debris, foreign particles, or other materials whose melting point is below the melting point of the other materials in the starting hemp material 106. Separation may occur using a sieve, a centrifuge, a filter, or any other apparatus or technique now known or later developed suitable for separating solids from a liquid and/or heated liquid, such as the substantially melted liquid.

[0026] In aspects of the technology, the substantially melted liquid, which may or may not have been treated using the one or more material separators 108, flows into the crystallization chamber 112. The illustrated crystallization chamber 112 may be used to precipitate out one or more cannabinoid isolates from the substantially melted liquid, which is illustrated as substantially melted liquid 116. For example, a catalyst may be introduced to the substantially melted liquid 116 and the substantially melted liquid may be cooled over a period to promote the precipitation of one or more cannabinoids from the substantially melted liquid 116. Additional/altemative information regarding such aspects of the technology is provided with reference to Fig. 2, below.

[0027] As illustrated, crystallization chamber 112 is temperature controlled, at least in part, using a jacket 114. Jacket 114 may have a thermal fluid, such as glycol, water, and/or oil, to assist in maintaining the liquid 116 within the chamber at or around a temperature. For example, upon being transferred to the crystallization chamber, the substantially melted liquid may be maintained at or around the melting point of the starting hemp material 106. The temperature may then be raised or lowered using the heat control provided, at least in part, by the jacket 114. It will be appreciated that other means of controlling temperature of the liquid within the crystallization chamber may be employed without deviating from the scope of the innovative concepts provided herein.

[0028] A false bottom with a mesh screen 118 may be employed to aid in separating the precipitate from the remaining liquid. For example, during crystallization, one or more cannabinoids may flocculate to the false bottom 118. The false bottom 118 may then be actuated to reveal a mesh screen, which, in aspects of technology, screens the one or more cannabinoid precipitate and allows the remainder liquid to be drawn off through effluent path 120. The precipitate may then be collected, such as by heating the precipitate such that it melts and drawing it off through collection stream 122. The collected stream may then be recycled back to the crystallization chamber for further crystallization processing or may be collected.

[0029] Fig. 2 is a method 200 for isolating crystalline cannabinoids. In examples, method 200 begins with providing a starting hemp material operation 202. For some applications, the starting hemp material is a solid mixture, semi-solid mixture, colloid, suspension, or solution having a composition made of, at least in part, various cannabis plant extract materials. In examples, the starting plant material may include varying amounts of cannabinoids. For example, the starting hemp material may contain various amounts of Cannabigerol (CBG), Cannabichromene (CBC), Cannabicyclol (CBL), Cannabinol (CBN), Cannabigerolic acid (CBGA), Cannabidivarin (CBDV), Cannabichromevarin (CBCV), Cannabigerovarin (CBGV), and Cannabigerol Monomethyl Ether. The mixture may also contain terpenes, fatty-acids, and other plant material. These terpenes, fatty-acids, and other plant material may be present because of the various means of producing the starting hemp material.

I. Selection! Producing Hemp Starting Material

[0030] Production of the starting hemp material may occur using a variety of methods suitable for extracting and/or separating the various cannabinoids, terpenes, fatty-acids, and other liquids and liquid soluble material from each other and the pulp and fibrous materials of the cannabis flower, stems, seeds, stalks of a cannabis plant, or any combination thereof. The methods and techniques may be performed in combination with each other. In particular, CO2 extraction, liquid extraction, decarboxylation, and distillation may be performed on hemp flower, hemp stalks, hemp stems, hemp seeds, and/or hemp pellets to obtain a suitable starting hemp material. For example, CO2 extraction yields raw cannabis oil. The raw hemp oil may then be decarboxylated to form decarboxylated hemp oil. That decarboxylated hemp oil may then be distilled to form a distillate, and that distillate may be the starting hemp material for operation 202. Additionally /alternatively, the raw hemp oil and/or decarboxylated hemp oil may be used as the starting hemp material. a. C0₂/Liquid Extraction

[0031] The various cannabinoids, terpenes, fatty-acids, and other liquids and liquid soluble material may be extracted using CO2 extraction or liquid-solid solvent extraction. The resulting extract, from CO2 or liquid solvent extraction, is referred to herein as raw cannabis oil and bulk cannabis oil, respectively. Raw cannabis oil and bulk cannabis oil may be provided as starting hemp material in operation 202.

[0032] Known CO2 extraction methods include U.S. Patent No. 8,895,078, Method for Producing and Extract from Cannabis Plant Matter, Containing a Tetrahydrocannabinol and a Cannabidiol and Cannabis Extracts to Mueller, filed October 16, 2003; and Chinese Patent Publication Number 105505565A, Method for Extracting Industrial Hemp Oil Rich in

(Tengchunjuan) et al., filed December 28, 2015.

[0033] Bulk cannabis oil, in aspects of the technology, is derived using a liquid extraction method that includes milling cannabis flower by transferring cannabis flower to a hammer mill where the flower is milled into a raw cannabis powder. This hammer milled raw cannabis powder may then transferred to the pellet mill where the hammer milled raw cannabis powder is compressed into approximately 2 cm x 0.5 cm pellets. These raw cannabis pellets are then transferred to an extraction column. The extraction column is then filled with a solvent, such as acetone (e.g., 2.9:1 lbs. of raw cannabis pellets to 1 liter of acetone). The raw cannabis pellets may be soaked in acetone for a period of time, such as 3 hours, and then the dark brown-green acetone/raw cannabis extract may be pumped into a receiving container, leaving the raw cannabis pellets behind. The hemp pellets may be subjected to an additional liquid extraction.

For example, additional solvent (e.g., acetone) may be added to the column containing the previously extracted raw cannabis pellets, and the previously extracted raw cannabis pellets may be soaked for an additional amount of time. This process may be repeated one or more additional times. The products of all extractions (e.g., the acetone/raw cannabis extract) are combined. This method produces a solvent-based cannabis extract, which may then be concentrated by evaporating some or substantially all of the solvent. This may occur by subjecting the solvent- cannabis extract to a lower pressure and/or higher temperatures than standard atmospheric temperatures and pressures (e.g., 50 °C). After the removal of some or substantially all solvent, the remaining bulk cannabis oil is a viscous dark brown/green mixture. Each of the raw hemp oil and the bulk hemp oil may be provided as a starting hemp material for operation 202. b. Decarboxylation

[0034] Raw cannabis oil may be decarboxylated by heating the raw cannabis oil. In aspects of the technology, the raw cannabis oil may be heated to 120 °C for a specified amount of time, such as 2 hours. This decarboxylated cannabis extract may then be used the starting hemp material for operation 202. c. Remediated Distillate

[0035] Aspects of the technology relate to using remediated distillate as a starting hemp material for operation 202. As provided herein, remediated distillate is formed by distilling decarboxylated cannabis oil to form a distillate. The distillate is then mixed with an organic solvent, such as heptane. In particular aspects of the technology, the distillate is combined at a ratio of 1 liter of heptane to one kg distillate and that combination is heated to about 50-60 °C to provide a substantially homogeneous mixture. In further aspects of the technology, the substantially homogeneous mixture is allowed to cool to about room temperature. In some aspects of the technology, the substantially homogeneous mixture is further cooled to about -10 °C to about 0 °C to provide a cooled mixture. In aspects, the mixture is held at around -10 °C to around 0 °C for at least 2 hours. The mixture may then be filtered to provide a filtrate and a precipitate. The precipitate, also known as the remediated distillate, is collected and is a substantially solid mixture. In aspects, the precipitate comprises CBD having at least about 94% purity and the precipitate has not more than 0.3% THC. In further aspects, the precipitate comprises CBD having about 90-95% purity.

[0036] It is believed that any starting hemp material having higher than 65% CBD, CBN, CBG composition by weight is preferred for implementing aspects of the technology described herein. II. Solvent-limited Crystallization of Starting Hemp Material [0037] After providing the starting hemp material, method 200 proceeds to operation 204, heating the starting hemp material. Heating the starting hemp material operation 204 may include identifying a melting point (identified melting point) for a solid or semi-solid material. Where the starting hemp material is remediated distillate, the melting point may be between about 40 °C and about 55 °C. In other aspects of the technology, heat will be applied to the starting hemp material to cause the starting hemp material to melt. In some aspects, heat is controlled such that the temperature of the starting hemp material is raised to about 2 °C to about 3 °C above the identified melting point. In other aspects of the technology, the temperature is set at or about the identified melting point. In aspects of the technology, the heating of the remediated distillate is to a temperature range that results in a substantially melted solution. As a result of operation 204, the substantially melted solution will have a liquid composition, though some solids may be present.

[0038] Method 200 then proceeds to operation 206. In operation 206, a catalyst is added to the substantially melted solution to form a mixture. In aspects of the technology, a seed cannabinoid crystal is added to the melted solution. For example, a relatively pure (e.g., above 90%, above 92%, above 94%, above 96%, and above 98% by weight isolate cannabinoid) cannabinoid crystal may be added. Such crystal may be CBD, CBG, CBN, or combination thereof. In other aspects, other catalysts may be used such as glass bead, glass plate, metal plate, or other substance capable of contributing to crystallization.

[0039] Method 200 optionally proceeds to filter operation 208, where the mixture is filtered before proceeding to operation 210. The filter operation 208 may aid in separating foreign matter from the solution. In some aspects of the technology, the filtering occurs via mechanical separation. For example, a mesh filter having opening sizes of no greater than 100, 150, 200,

250, 300, or 350 micrometers may be used.

[0040] Method 200 then proceeds to operation 210, cooling of the mixture. In aspects of the technology, operation 210 cools the mixture to a temperature that results in at least one compound precipitating out of the mixture as a solid to form the at least one compound and a remainder solution. Cooling of the mixture may occur using a variety of means. In examples, the mixture is exposed to a chilled ambient environment. In other examples, a vessel with a cooling jacket may be used. Still, in other examples, the mixture may be exposed to a room temperature (i.e., about 20-22 °C). In some aspects of the technology, the rate of cooling is controlled. For example, the cooling of the mixture may occur and/or be controlled by cooling the mixture at a rate of about 1 °C per 24 hours for a period of about 4 to about 7 days. In operation 208, the mixture may be agitated during the cooling of the mixture. Various means to control temperature and agitation speed may be employed.

[0041] As illustrated, method 200 proceeds to operation 212, where the precipitate is collected.

In operation 212, the precipitate is aggregated by separating the remaining solution from the precipitate. Separation may occur through a variety of means, such as by drawing off the remainder solution. In aspects of the technology operation 212 may include drawing off the remainder solution from the least one compound using a mechanical filter as further described with reference to Fig. 1. In an example, the purge gas may be selected from the group consisting of air, argon, nitrogen, and any combination thereof.

[0042] Method 200 proceeds to decision 214. In decision 214, it is determined whether the aggregate precipitate collected in operation 212 should be processed again. That is, in some instances, it may be desirous to perform steps 204 to 214 on the aggregate precipitate again to obtain a more purified precipitate (e.g., a higher concentration of CBN by weight). The decision may depend on determining the purity of the aggregate precipitate. For example, where the aggregate precipitate is tested to be at about 93% CBD, but a desired concentration is about 96% CBD, it may be determined to retreat the aggregate precipitate. Where it is determined to process the aggregate precipitate again, method 200 returns to operation 204, where the aggregate precipitate is treated as the starting hemp material. Where it is determined not to reprocess the aggregate precipitate, method 200 ends.

Examples

[0043] In a first example, distilled remediated hemp distillate (distillate) with the below cannabinoid profile was obtained using aspects of the technology provided above.

[0044] The melting point range of the distillate was determined to be 43-46 °C. In a 5 liter, jacketed glass reactor with internal temperature monitoring and overhead mechanical stirring, the distillate (2 kg) was warmed to 55 °C and gently stirred (60 rpm). The resulting homogenous oil was filtered through celite into another 5 -liter jacketed glass reactor with internal temperature monitoring and overhead mechanical stirring. The homogenous oil was held at 47 °C and gently stirred (60 rpm). Seed crystals of cannabidiol were added and the mixture was gently stirred overnight. Every 24 hours, the temperature of the reactor was lowered 1 °C. Slow crystal growth was observed over 7 days of this process. After 7 days, at a temperature of 41 °C, the remaining oil was filtered away from the crystalline solids, leaving a solid with the below cannabinoid profile:

and a resulting filtrate with the below cannabinoid profile:

[0045] The resulting powder was reprocessed through using aspects of the melting and recrystallization technology described herein. The melting point range was determined to be 52- 56 °C. In a 5 liter jacketed glass reactor with internal temperature monitoring and overhead mechanical stirring, the distillate (2 kg) was warmed to 57 °C and gently stirred (60 rpm). Seed crystals of cannabidiol were added and the mixture was gently stirred overnight. Every 24 hours, the temperature of the reactor was lowered 1 °C. Slow crystal growth was observed over 7 days of this process. After 7 days, at a temperature of 51 °C, the remaining oil was filtered away from the crystalline solids, leaving a solid with the below cannabinoid profile:

[0046] Only cannabidiol (CBD) was detected. [0047] In a second example, a distilled hemp oil (distillate) with the below cannabinoid profile was obtained:

[0048] The melting point range of the distillate was determined to be 44-48 °C. In a 5 liter, jacketed glass reactor with internal temperature monitoring and overhead mechanical stirring, the distillate (2 kg) was warmed to 55 °C and gently stirred (60 rpm). The resulting homogenous oil was filtered through celite into another 5 liter jacketed glass reactor with internal temperature monitoring and overhead mechanical stirring. The homogenous oil was held at 49 °C and gently stirred (60 rpm). Seed crystals of cannabidiol were added and the mixture was gently stirred overnight. Every 24 hours, the temperature of the reactor was lowered 1 °C. Slow crystal growth was observed over 7 days of this process. After 7 days, at a temperature of 43 °C, the remaining oil was filtered away from the crystalline solids, leaving a solid with the below cannabinoid profile:

and a resulting filtrate with the below cannabinoid profile:

Tetrahydrocannabinol (THC)

3.0%

[0049] The resulting powder was reprocessed through the same method. The melting point range was determined to be 54-58 °C. In a 5 liter, jacketed glass reactor with internal temperature monitoring and overhead mechanical stirring, the distillate (2 kg) was warmed to 59 °C and gently stirred (60 rpm). Seed crystals of cannabidiol were added and the mixture was gently stirred overnight. Every 24 hours, the temperature of the reactor was lowered 1 °C. Slow crystal growth was observed over 7 days of this process. After 7 days, at a temperature of 53 °C, the remaining oil was filtered away from the crystalline solids, leaving a solid with the below cannabinoid profile:

[0050] Only cannabidiol (CBD) was detected.

Claims

Example Claims What is claimed is:

1. A method for isolating crystalline cannabinoids, the method comprising: providing a remediated distillate, wherein the remediated distillate is at least partially a solid; heating the remediated distillate to a temperature range to form a substantially melted solution; adding a catalyst to the substantially melted solution to form a mixture; cooling the mixture to a temperature so that at least one compound precipitates out of the mixture as a solid to form the at least one compound and a remainder solution; and collecting the at least one compound.

2. The method of claim 1, wherein the temperature is between about 40 °C and about 55 °C.

3. The method of claim 1, wherein collecting the at least one compound comprises: drawing off the remainder solution from the at least one compound by filtering the solution in the presence of a purge gas.

4. The method of claim 3, wherein the purge gas is selected from a group consisting of air, argon, nitrogen, and any combination thereof.

5. The method of claim 1, further comprising a purify operation after the collecting the at least one compound operation, wherein the purify operation comprises: providing the at least one compound, wherein the at least one compound is at least partially a solid; heating the at least one compound to a temperature range to form a second substantially melted solution; adding a catalyst to the second substantially melted solution to form a second mixture; cooling the second mixture to a temperature so that at least one purified compound precipitates out of the mixture as a solid to form the at least one purified compound and a remainder solution; and collecting the at least one purified compound.

6. The method of claim 5, wherein the purify operation is performed at least one additional time on the at least one purified compound.

7. The method of claim 1, wherein the catalyst is a cannabinoid isolate in crystalline form.

8. The method of claim 7, wherein the cannabinoid isolate is selected from the group consisting of cannabidiol and cannabigerol.

9. The method of claim 1, wherein the cooling of the mixture comprises cooling the mixture at a rate of about 1° C per 24 hours for a period of about 4 to about 7 days.

10. The method of claim 1, further comprising agitating the mixture.

11. The method as in claim 3, further wherein the filtering occurs by passing the mixture through a filter having a restriction of no greater than 200 micrometers.

12. A system for isolating crystalline cannabinoids, the system comprising: a pre-treatment chamber in fluidic communication, via a transfer conduit, with a crystallization chamber having at least one inner wall and at least one outer wall, wherein the transfer conduit includes a filter mechanism; a starting material disposed within the pre-treatment chamber; a heating element in thermal communication with the pre-treatment chamber capable of directing heat to the starting material; and a thermal regulating jacket coupled to at least a portion of the at least one outer wall of the crystallization chamber.

13. The system of claim 12, wherein the filter mechanism comprises a mesh screen.

14. The system of claim 12, wherein the transfer conduit comprises: a first pipe having a pre-treatment end and a filter end, wherein the pre-treatment end is coupled to the pre-treatment chamber and the filter end is coupled to the filter mechanism; a second pipe having a filtered end and a crystallization end, wherein the filtered end is coupled to the filter mechanism and the crystallization end is coupled to the crystallization chamber.

15. The system of claim 12, wherein the crystallization chamber includes an agitator.

16. The method of claim 15, wherein the pre-treatment chamber includes an inner pre treatment wall defining a volume, and the agitator comprises a paddle disposed within the volume.