Systems and methods for cannabis extraction

Abstract

This disclosure provides methods and systems for the supercritical fluid extraction of cannabinoids from cannabis. The supercritical fluid extraction of cannabinoids is performed with carbon dioxide (CO 2 ) balanced with one or more hydrocarbons, such as propane, propene, and propadiene. As demonstrated, the extraction can be carried out at maximum efficiency and energy savings while keeping the wax formation at minimum by lowering temperature. The methods and systems disclosed herein reduce the production time and safety/environmental hazards and are suitable for proper and safe extraction in non-GMP and GMP environments.

What is claimed is: 
     
         1 . A method for cannabis extraction, comprising:
 (i) contacting cannabis plant material with a supercritical fluid solvent system comprising carbon dioxide (CO 2 ) and a hydrocarbon co-solvent;   (ii) obtaining a first fraction of the supercritical fluid solvent system containing a first cannabis extract during a first period of time;   (iii) obtaining a second fraction of the supercritical fluid solvent system containing a second cannabis extract during a second period of time; and   (iv) removing the CO 2  and the hydrocarbon co-solvent from the first fraction of the supercritical fluid solvent system and the second fraction of the supercritical fluid solvent system, thereby obtaining the first cannabis extract and the second cannabis extract.   
     
     
         2 . The method of  claim 1 , wherein the first cannabis extract comprises terpene and the second cannabis extract comprises cannabinoids. 
     
     
         3 . The method of  claim 1 , wherein the cannabis plant material comprises fresh frozen. 
     
     
         4 . The method of  claim 1 , wherein the first period of time is between about 2 minutes and about 30 minutes and the second period of time is between about 30 minutes and about 24 hours. 
     
     
         5 . The method of  claim 1 , wherein the hydrocarbon co-solvent is selected from the group consisting of propane, propene, propadiene, and a combination thereof. 
     
     
         6 . The method of  claim 1 , wherein a molar ratio of carbon dioxide to the hydrocarbon co-solvent is (i) between about 0.75 to about 0.25 and about 0.98 to about 0.02 or (ii) between about 0.95 to about 0.05. 
     
     
         7 . The method of  claim 1 , wherein the step of contacting is performed at a pressure between about 650 psi and about 800 psi. 
     
     
         8 . The method of  claim 1 , wherein the step of contacting is performed at a temperature between about 32° F. and about 38° F. 
     
     
         9 . The method of  claim 1 , comprising repeating steps (a) and (b) at least once. 
     
     
         10 . The method of  claim 1 , wherein the cannabis extract comprises terpene oil. 
     
     
         11 . The method of  claim 1 , wherein the extraction efficiency of terpene is at least 50% higher than a predetermined reference value. 
     
     
         12 . The method of  claim 1 , wherein the cannabis extract comprises one or more cannabinoids selected from the group consisting of: tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), cannabicyclol (CBL), cannabivarin (CBV), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabigerol monomethyl ether (CBGM), and a combination thereof. 
     
     
         13 . The method of  claim 1 , wherein the cannabis plant material is processed from  Cannabis sativa  or  Cannabis indica.    
     
     
         14 . The method of  claim 14 , further comprising grinding  Cannabis sativa  or  Cannabis indica  into ground cannabis plant material. 
     
     
         15 . The method of  claim 1 , wherein the wax formation is reduced by at least 10% compared to a predetermined reference value. 
     
     
         16 . The method of  claim 1 , further comprising purifying the cannabis extract by employing at least one of chromatography, adsorption, crystallization, distillation, liquid-liquid extraction, filtration, fractional distillation, precipitation, recrystallization, and sublimation. 
     
     
         17 . A system for cannabis extraction, comprising:
 at least one extractor configured to receive plant material and a supercritical fluid solvent system comprising carbon dioxide (CO 2 ) and a hydrocarbon co-solvent;   an accumulator connected to the extractor and configured to feed the supercritical fluid solvent system to the extractor; and   at least one container connected to the extractor and configured to receive the extract generated from the plant material.   
     
     
         18 . The system of  claim 18 , wherein the plant material is cannabis plant material or coffee or tea leaves. 
     
     
         19 . The system of  claim 18 , further comprising a first reservoir for CO 2  and a second reservoir for the hydrocarbon co-solvent, wherein the first reservoir and the second reservoir are connected to the accumulator and configured to feed CO 2  and the hydrocarbon co-solvent to the accumulator in which CO 2  and the hydrocarbon co-solvent are blended at a predetermined molar ratio.