Reputable manufacturers of CBD oil prefer CO2 extraction to other CBD oil extraction methods for the specific benefits it offers. When compared to other solvent extraction methods like the ones that use butane and hexane, CO2 extraction uses the non-toxic solvent – CO2. The higher efficiency of CO2 extraction in pulling out all beneficial compounds from hemp extract is an added benefit of the extraction method.
What Is Supercritical CO2 Extraction?
CO2 extraction is of three types, namely supercritical, sub-critical, and mid-critical extraction. In this article, we focus on the supercritical mode of extraction. CO2 is a gas at standard temperature and pressure. It enters a state between liquid and gas when it is heated above 31.1 at 1071 psi pressure and higher. 31.1 and 1071 psi are the critical temperatures and critical pressure of CO2 respectively.
How Does Supercritical CBD Extraction Work?
One way of extracting CBD using CO2 solvent is given below:
- Start with liquid CO2 and raise its pressure using a compressor and temperature using a heater.
- The above step converts liquid CO2 into a supercritical state, which is then passed through the ground hemp extract placed in an extractor.
- The supercritical CO2 passed through the plant material pulls out essential phytochemicals from hemp.
- The extracted components are then passed through a separator to break them down into constituent parts.
- The trichomes and other beneficial components are sent to a collection receptacle, while the supercritical CO2 is passed through a condenser to turn it back to a liquid state.
Difference Between Supercritical Extraction And Subcritical Extraction
Subcritical extraction involves lower temperature and pressure than that of supercritical CO2 extraction. In subcritical extraction, the CO2 solvent is in its liquid state. The differences in temperature and pressure account for the differences in the consistency of the resultants of extraction.
If supercritical CO2 extraction is performed without fractionation, the final CO2 hemp extract has the consistency of peanut butter. To remove the fats and waxes from it, a step named winterization has to be performed. The process involves mixing CBD extract with ethanol after which the mixture is placed in the freezer for 24 hours. When the chilled mixture is taken out of the freezer and run through a filter paper, the fats and waxes can be efficiently removed from it. The consistency of the extract produced after hemp undergoes subcritical extraction resembles the consistency of molasses.
When you buy CBD oil, check the CBD extraction method employed in its manufacturing to ensure that the product was made using safe extraction methods.