US 12,391,637 B2
Methods to separate cannabinoids from impurities by crystallization
C. Russell Thomas, Boulder, CO (US); and Douglas G. Metcalf, Boulder, CO (US)
Assigned to Natural Extraction Systems, LLC, Boulder, CO (US)
Appl. No. 17/775,856
Filed by Natural Extraction Systems, LLC, Boulder, CO (US)
PCT Filed Nov. 10, 2020, PCT No. PCT/US2020/059884
§ 371(c)(1), (2) Date May 10, 2022,
PCT Pub. No. WO2021/096886, PCT Pub. Date May 20, 2021.
Claims priority of provisional application 63/056,311, filed on Jul. 24, 2020.
Claims priority of provisional application 62/933,751, filed on Nov. 11, 2019.
Prior Publication US 2022/0396540 A1, Dec. 15, 2022
Int. Cl. C07C 37/84 (2006.01)
CPC C07C 37/84 (2013.01) [C07B 2200/13 (2013.01)] 20 Claims
 
1. A method to produce cannabinoid crystals, comprising:
(a) providing a precursor composition that comprises (i) a precursor, (ii) contaminant precursors, (iii) original lipids, and (iv) original organic matter, wherein:
either (i) the precursor is cannabidiolic acid, and the contaminant precursors consist of tetrahydrocannabinolic acid and cannabichromenic acid, or (ii) the precursor is cannabidivarnic acid, and the contaminant precursors consist of tetrahydrocannabivarin acid and cannabichromevarin acid;
the original lipids consist of one or more of n-nonane; n-decane; n-undecane; n-dodecane; n-tridecane; n-tetradecane; n-pentadecane; n-hexadecane; n-heptadecane; n-octadecane; n-nonadecane; n-icosane; n-heneicosane; n-docosane; n-tricosane; n-tetracosane; n-pentacosane; n-hexacosane; n-heptacosane; n-octacosane; n-nonacosane; n-triacontane; n-hentriacontane; n-dotriacontane; 3,6-dimethyl-tridecane; 2,6-dimethyl-tetradecane; 2,6-dimethyl-hexadecane; 3,6-dimethyl-heptadecane; 3,7-dimethyl-heptadecane; 3,6-dimethyl-octadecane; 3,7-dimethyl-octadecane; 3-methyl-heneicosane; 3-methyl-tricosane; 2-methyl-tetracosane; 3-methyl-pentacosane; 2-methyl-hexacosane; 3-methyl-heptacosane; and 3-methyl-triacontane;
the original organic matter consists of plant-derived molecules and ions that do not vaporize at any temperature of less than 235 degrees Celsius at atmospheric pressure; and
the precursor composition comprises the precursor at a concentration of at least 4 percent by mass;
(b) heating the precursor composition to produce a decarboxylated composition that comprises (i) a cannabinoid, (ii) contaminants, (iii) lipids, and (iv) organic matter, wherein:
the heating converts at least 90 percent of the precursor into (i) the cannabinoid and (ii) carbon dioxide by mole of the precursor;
either (i) the precursor is cannabidiolic acid, and the cannabinoid is cannabidiol, or (ii) the precursor is cannabidivarnic acid, and the cannabinoid is cannabidivarin;
the heating converts at least 90 percent of the contaminant precursors into (i) the contaminants and (ii) carbon dioxide by mole of the contaminant precursors;
either (i) the contaminant precursors consist of tetrahydrocannabinolic acid and cannabichromenic acid, and the contaminants consist of tetrahydrocannabinol and cannabichromene, or (ii) the contaminant precursors consist of tetrahydrocannabivarin acid and cannabichromevarin acid, and the contaminants consist of tetrahydrocannabivarin and cannabichromevarin;
the lipids consist of a portion of the original lipids that survive the heating; and
the organic matter consists of a portion of the original organic matter that survives the heating;
(c) combining a portion of the decarboxylated composition with ethanol to produce a dewaxing composition that comprises (i) ethanol, (ii) a portion of the cannabinoid of the decarboxylated composition, (iii) a portion of the contaminants of the decarboxylated composition, (iv) a portion of the lipids of the decarboxylated composition, and (v) a portion of the organic matter of the decarboxylated composition, wherein:
the portion of the cannabinoid of the decarboxylated composition comprises the cannabinoid at a concentration of at least 30 percent and no greater than 80 percent by mass;
the portion of the cannabinoid of the decarboxylated composition comprises the cannabinoid and the contaminants at a ratio of at least 3:1 and no greater than 80:1 by mass;
the portion of the cannabinoid of the decarboxylated composition comprises the cannabinoid and the lipids at a concentration of at least 1:2 and no greater than 40:1 by mass;
the portion of the cannabinoid of the decarboxylated composition comprises the cannabinoid and the organic matter at a concentration of at least 1:2 and no greater than 40:1 by mass; and
the dewaxing composition comprises the ethanol at a concentration of at least 20 percent and no greater than 90 percent by mass;
(d) cooling a portion of the dewaxing composition to produce a mixture that comprises (i) a portion of the ethanol of the dewaxing composition, (ii) a portion of the cannabinoid of the dewaxing composition, (iii) a portion of the contaminants of the dewaxing composition, (iv) a portion of the lipids of the dewaxing composition, and (v) a portion of the organic matter of the dewaxing composition, wherein:
the mixture comprises a solid phase and a liquid phase;
the cooling converts at least 65 percent of the portion of the lipids of the dewaxing composition into solid-phase lipids by mass such that the solid phase of the mixture comprises at least 65 percent of the lipids of the mixture by mass;
the liquid phase comprises at least 90 percent of the ethanol of the mixture by mass;
the liquid phase comprises at least 90 percent of the cannabinoid of the mixture by mass;
the liquid phase comprises at least 90 percent of the contaminants of the mixture by mass; and
the liquid phase comprises at least a portion of the organic matter of the mixture;
(e) separating a portion of the liquid phase from the solid phase to produce a dewaxed composition that comprises (i) a portion of the ethanol of the liquid phase, (ii) a portion of the cannabinoid of the liquid phase, (iii) a portion of the contaminants of the liquid phase, and (iv) a portion of the organic matter of the liquid phase;
(f) separating ethanol from a portion of the dewaxed composition to produce a concentrate composition that comprises (i) a portion of the cannabinoid of the dewaxed composition, (ii) a portion of the contaminants of the dewaxed composition, and (iii) a portion of the organic matter of the dewaxed composition, wherein:
the separating is performed by vaporizing the ethanol from the portion of the dewaxed composition; and
the concentrate composition lacks ethanol at a concentration greater than 20 percent by mass;
(g) heating a portion of the concentrate composition to produce a vapor phase and residual organic matter, wherein:
the portion of the concentrate composition comprises the cannabinoid and the contaminants at a combined concentration of at least 40 percent and no greater than 85 percent by mass;
the vapor phase comprises (i) a portion of the cannabinoid of the concentrate composition and (ii) a portion of the contaminants of the concentrate composition;
the residual organic matter comprises a portion of the organic matter of the concentrate composition; and
the residual organic matter consists of one or both of a solid and a liquid;
(h) separating a portion of the vapor phase from the residual organic matter to produce a distillate that comprises (i) a portion of the cannabinoid of the vapor phase, and (ii) a portion of the contaminants of the vapor phase;
(i) condensing a portion of the distillate into a condensed phase that comprises (i) a portion of the cannabinoid of the distillate, and (ii) a portion of the contaminants of the distillate, wherein:
the condensed phase comprises the cannabinoid at a concentration of at least 70 percent and no greater than 90 percent by mass; and
the condensed phase comprises the contaminants at a concentration of at least 1 percent and no greater than 20 percent by mass;
(j) combining a portion of the condensed composition and ethanol to produce a crystallization composition that comprises (i) ethanol, (ii) a portion of the cannabinoid of the condensed phase, and (iii) a portion of the contaminants of the condensed phase;
(k) incubating a portion of the crystallization composition at a crystallization temperature to produce crystals and residual liquid, wherein:
the cannabinoid has both a concentration and a solubility in the portion of the crystallization composition, and the crystallization temperature is a temperature at which the concentration is greater than the solubility;
the crystals comprise a portion of the cannabinoid of the crystallization composition; and
the residual liquid comprises a portion of the ethanol of the crystallization composition and a portion of the contaminants of the crystallization composition; and
(l) separating a portion of the crystals from the residual liquid to produce a product, wherein:
the product comprises the cannabinoid at a concentration of at least 90 percent by mass;
the product lacks the contaminants at a concentration of greater than 0.3 percent by mass;
the product lacks the lipids at a concentration of greater than 1 percent by mass;
the product lacks the organic matter at a concentration greater than 1 percent by mass;
the crystals are a solid;
the crystals have a melting point; and
the crystals lack a glass-transition temperature.