Production of cannabidiol from hemp using subcritical liquid carbon dioxide

A method for extracting cannabidiol from hemp that comprises the steps of:

• a) Providing an apparatus comprising 2 separate vessels;
• b) Milling dried hemp biomass in order to obtain a product having a bulk density of at least 0.2 g/cm3;
• c) Decarboxylating the dried biomass of step b);
• d) Filling the first vessel with the milled and decarboxylated biomass of step c);
• e) Extracting a product comprising cannabidiol, tetrahydro-cannabinol Δ9-THC and Δ8-THC and other cannabinoids from the milled and decarboxylated biomass by injecting subcritical liquid carbon dioxide at a pressure of at least 65 bars and a temperature of less than 31° C., using a mass ratio carbon dioxide to biomass of at least 10 kg CO2/kg biomass and for a period of time ranging between 30 minutes and 8 hours;
• f) Retrieving the extraction product from step e) from the first vessel and loading it onto a support selected from celite, acidic, neutral or basic alumina or silica with a mass ratio extraction product to support ranging between 1 and 20 mass %;
• g) Loading the support of step f) into the second vessel;
• h) Submitting the second vessel of step g), containing a support loaded with the extraction products, to a flow of subcritical liquid carbon dioxide at a mass ratio carbon dioxide to biomass of at least 10 kg CO2/kg biomass and for a period of time ranging between 30 minutes and 8 hours in order to separate cannabidiol;
• and
• i) Separating and retrieving cannabidiol.

A CBD isolate obtained by a method comprising:

• steps a) through i):
• a) Providing an apparatus comprising 2 separate vessels;
• b) Milling dried hemp biomass in order to obtain a product having a bulk density of at least 0.2 g/cm3;
• c) Decarboxylating the dried biomass of step b);
• d) Filling the first vessel with the milled and decarboxylated biomass of step c);
• e) Extracting a product comprising cannabidiol, tetrahydro-cannabinol Δ9-THC and Δ8-THC and other cannabinoids from the milled and decarboxylated biomass by injecting subcritical liquid carbon dioxide at a pressure of at least 65 bars and a temperature of less than 31° C., using a mass ratio carbon dioxide to biomass of at least 10 kg CO2/kg biomass and for a period of time ranging between 30 minutes and 8 hours;
• f) Retrieving the extraction product from step e) from the first vessel and loading it onto a support selected from celite, acidic, neutral or basic alumina or silica with a mass ratio extraction product to support ranging between 1 and 20 mass %;
• g) Loading the support of step f) into the second vessel;
• h) Submitting the second vessel of step g), containing a support loaded with the extraction products, to a flow of subcritical liquid carbon dioxide at a mass ratio carbon dioxide to biomass of at least 10 kg CO2/kg biomass and for a period of time ranging between 30 minutes and 8 hours in order to separate cannabidiol;
• and
• i) Separating and retrieving cannabidiol;
• or steps a) through b) in combination with steps A) through H):
• A) Providing 2 vessels connected to each other;
• B) Milling dried hemp biomass in order to obtain a product having a bulk density of at least 0.2 g/cm3;
• C) Decarboxylating the dried biomass of step B);
• D) Filling the first vessel with the milled and decarboxylated biomass of step C);
• E) Filling the second vessel with a support selected from celite, acidic, neutral or basic alumina or silica:
• F) In the first vessel, extracting a product comprising cannabidiol, Δ9-THC and Δ8-THC and other cannabinoids from the milled and decarboxylated biomass using subcritical liquid carbon dioxide at a pressure of at least 65 bars and a temperature of less than 31° C., with a mass ratio carbon dioxide to biomass of at least 10 kg CO2/kg biomass and for a period of time ranging between 30 minutes and 8 hours;
• G) Flowing the extraction product of step F) into the second vessel filled with support and submitting said second vessel to the same flow of subcritical liquid carbon dioxide using the same mass ratio carbon dioxide to biomass, the same temperature and the same pressure as in the first vessel and for a period of time ranging between 30 minutes and 8 hours;
• and
• H) Separating and retrieving cannabidiol,
• and characterised in that said isolate is devoid of other cannabinoids, including controlled cannabinoids such as THC, THCA and CBN.