Treatment of spent cannabis biomass with activating agent

1. A process for treating spent cannabis biomass comprising:

mixing spent cannabis biomass with an activating agent to result in an impregnated spent cannabis biomass;

raising the impregnated spent cannabis biomass to a first temperature that is sufficient to remove water and volatile components from the impregnated spent cannabis biomass;

raising the impregnated spent cannabis biomass to a second temperature that is sufficient to recover cannabinoids from the impregnated spent cannabis biomass, wherein the second temperature is higher than the first temperature;

collecting the recovered cannabinoids by directing them into chilled ethanol:

raising to a third temperature the impregnated spent cannabis biomass, wherein the third temperature is higher than the second temperature; and

maintaining the impregnated spent cannabis biomass at the third temperature until the impregnated spent cannabis biomass has been transformed into activated carbon.

2. The process of claim 1 , wherein:

the activating agent is KOH, H 3 PO 4 or ZnCl 2 ; and

the spent cannabis biomass is mixed with the activating agent at a ratio of between 1:0.5 and 1:3 by weight.

3. The process of claim 1 , wherein the activating agent is mixed with the spent cannabis biomass for 2 to 24 hours.

4. The process of claim 1 , wherein:

the impregnated spent cannabis biomass is maintained at the third temperature for 0.5 to 2 hours; and

the third temperature is between 500 and 900° C.

5. The process of claim 1 , wherein the first temperature is 100±20° C. and the second temperature is 170-500° C.

6. The process of claim 5 , wherein the first temperature is 100° C. and the second temperature is 500° C.

7. The process of claim 1 , wherein the impregnated spent cannabis biomass is heated in a fixed bed reactor that has an exhaust line with a bypassable cold trap, the process comprising purging the fixed bed reactor with nitrogen before heating the impregnated spent cannabis biomass.

8. The process of claim 7 , comprising, while raising the impregnated spent cannabis biomass to the first temperature, directing vapor evaporated from the impregnated spent cannabis biomass to bypass the cold trap.

9. The process of claim 8 , comprising, while raising the impregnated spent cannabis biomass from the first temperature to the second temperature, passing vapor evaporated from the impregnated spent cannabis biomass through the cold trap.

10. The process of claim 1 , comprising maintaining the impregnated spent cannabis biomass at the first temperature until all the water is removed from the impregnated spent cannabis biomass.

11. The process of claim 1 , comprising collecting water and volatile components from the impregnated spent cannabis biomass using a cold trap, while the impregnated spent cannabis biomass is below and at the first temperature.

12. The process of claim 1 , comprising maintaining the impregnated spent cannabis biomass at the second temperature until all the cannabinoids have been recovered from the impregnated spent cannabis biomass.

13. The process of claim 1 , comprising maintaining the impregnated spent cannabis biomass at the third temperature for 1 hour.

14. The process of claim 1 , comprising passing nitrogen gas over the impregnated spent cannabis biomass throughout the process.

15. The process of claim 1 , comprising milling the spent cannabis biomass to an average particle size below 2 mm prior to mixing the spent cannabis biomass with the activating agent.

16. The process of claim 1 , comprising washing the activated carbon with hot deionized water when the activating agent is acidic.

17. The process of claim 1 , comprising washing the activated carbon with a diluted HCl solution and then washing the activated carbon with deionized water, when the activating agent is alkaline.

18. The process of claim 1 , wherein the chilled ethanol is at a temperature between 0° C. and −40° C.