Hydrocarbon Extraction Has Four Primary Steps:
Step One (Washing): A cold solvent made of propane or butane-washes over the plant material (biomass) at a low temperature and pressure. This process removes the cannabinoids and terpenes from the biomass and dissolves them into the liquid solvent.
Step Two (Removing the Impurities): This step removes any waxes and lipids left in the solution. Unlike ethanol extraction that requires a day-long winterization process, hydrocarbon extraction has fewer waxes and lipids so the removal process is easier and does not take as much time. In most closed loop systems, a de-waxing column filters out any of the remaining waxes and lipids.
Step Three (Collection): The filtered solvent solution is collected into a new or separate container and the hydrocarbon solvent (propane, butane, or propane butane mix) is purged. Corken’s gas compressors (also known as recovery pump) remove the vapor formed by the solvent solution within the collection tank and returns it to the supply tank so it can be re-circulated.
Step Four (Purification): Depending on the desired final state of the product, a purification process may be necessary. Various methods such as a vacuum purge, centrifugal, and co-solvent separation are used to further refine the product.
The process map below illustrates each step mentioned above.