Purification and extraction of cannabinoids

Abstract

A method for purification and extraction of cannabinoids includes: providing a cannabis oil including phospholipids and cannabinoid acids; contacting the cannabis oil with a degumming solvent, wherein the degumming solvent and cannabis oil are substantially immiscible; and separating an aqueous phase including the degumming solvent and at least a portion of the phospholipids from an oil phase including the cannabis oil. The method may further include contacting the oil phase with an extraction solvent, where the extraction solvent and oil phase are substantially immiscible; and separating an aqueous phase including the extraction solvent and at least a portion of the cannabinoid acids from a second oil solvent phase including the oil phase and/or simply the liberated cannabinoids following acidification of the extraction solvent.

What is claimed is: 
     
         1 . A method, comprising:
 providing a cannabis oil comprising phospholipids;   contacting the cannabis oil with a degumming solvent, wherein the degumming solvent and cannabis oil are substantially immiscible; and   separating an aqueous phase comprising the degumming solvent and at least a portion of the phospholipids from an oil phase comprising the cannabis oil.   
     
     
         2 . The method according to  claim 1 , wherein the degumming solvent comprises 10 wt % citric acid in water. 
     
     
         3 . The method according to  claim 2 , wherein contacting the cannabis oil with the degumming solvent comprises introducing the cannabis oil and the degumming solvent into a fiber conduit contactor. 
     
     
         4 . The method according to  claim 1 , wherein, prior to contacting the cannabis oil with the degumming solvent, the cannabis oil is diluted in a solvent comprising a hydrocarbon and ethanol. 
     
     
         5 . The method according to  claim 4 , wherein the cannabis oil is diluted by a factor of at least 2. 
     
     
         6 . The method according to  claim 1 , wherein the cannabis oil comprises cannabinoids and wherein a concentration by weight of cannabinoids in the oil phase is at least 3% greater than a concentration by weight of cannabinoids in the cannabis oil. 
     
     
         7 . The method according to  claim 1 , wherein the oil phase comprises cannabinoid acids, the method further comprising:
 contacting the oil phase with an extraction solvent, wherein the extraction solvent and the oil phase are substantially immiscible; and   separating an aqueous phase comprising the extraction solvent and at least a portion of the cannabinoid acids from a second oil phase comprising the oil phase.   
     
     
         8 . A method, comprising:
 providing a cannabis oil comprising cannabinoid acids;   contacting the cannabis oil with an extraction solvent, wherein the extraction solvent and cannabis oil are substantially immiscible; and   separating an aqueous phase comprising the extraction solvent and at least a portion of the cannabinoid acids from an oil phase comprising the cannabis oil.   
     
     
         9 . The method according to  claim 8 , wherein the cannabinoid acids comprise cannabidiolic acid. 
     
     
         10 . The method according to  claim 8 , wherein the extraction solvent comprises water, an alcohol, and a base. 
     
     
         11 . The method according to  claim 10 , wherein the alcohol is ethanol and constitutes 5 to 30 wt % of the extraction solvent. 
     
     
         12 . The method according to  claim 10 , wherein the base is selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate and or a combination of bases. 
     
     
         13 . The method according to  claim 8 , wherein contacting the cannabis oil with the extraction solvent comprises introducing the cannabis oil and the extraction solvent into a fiber conduit contactor. 
     
     
         14 . The method according to  claim 13 , wherein separating the aqueous phase from the oil phase comprises separately removing the aqueous phase and the oil phase from a downstream end of the fiber conduit contactor. 
     
     
         15 . The method according to  claim 8 , further comprising: acidifying the extraction solvent with an aqueous acid, mixing the aqueous phase with an oil and or a solvent and reprocessing the combined mixture through a fiber reactor or other means to back extract the liberated acidic cannabinoids from the aqueous extraction solvent. 
     
     
         16 . The method according to  claim 15 , wherein the cannabis oil further comprises neutral cannabinoids and a weight ratio of cannabinoid acids to neutral cannabinoids in the second oil solvent phase is at least 2 times a weight ratio of cannabinoid acids to neutral cannabinoids in the cannabis oil. 
     
     
         17 . The method according to  claim 8 , wherein the cannabis oil further comprises neutral cannabinoids and a weight ratio of cannabinoid acids to neutral cannabinoids in the oil phase is no more than 0.8 times a weight ratio of cannabinoid acids to neutral cannabinoids in the cannabis oil. 
     
     
         18 . The method according to  claim 8 , wherein the cannabinoid acids comprise tetrahydrocannabinolic acid. 
     
     
         19 . The method according to  claim 8 , wherein the cannabinoid acids comprise cannabigerolic acid. 
     
     
         20 . The method according to  claim 8 , wherein the extraction solvent comprises 70-95 wt % water, 5-30 wt % ethanol, and 0.25-5 wt % of a base selected from sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate and or a combination of bases.