What is the difference in extraction processes?
So much confusion about extraction methods. There are three main types of extraction. Dr. Ryan McKinney explains the difference below.
Differentiating Between Extraction Processes by Dr. Ryan McKinnie
Supercritical CO2 offers several advantages over cryo-ethanol and hydrocarbon (butane/lighter fluid) extraction of cannabinoids from hemp/cannabis. The main advantage is that no toxic solvents are used in the extraction as any residual CO2 evaporates post extraction leaving behind a clean and solvent free extract. Supercritical CO2 is also much more selective in what is extracted than the other methods. The desired cannabinoids and terpenes in the hemp/cannabis plant can be targeted while the majority of the plant waxes/lipids and chlorophyll are left behind. Cryo-ethanol extraction extracts much more of the undesired elements of the plant material in contrast. The other issue with ethanol based extraction is that hemp processors must pay the excise tax for 200 proof food grade ethanol. This increases the cost per 55 gallon drum from $500 per barrel to $1600 per barrel. Most processors are not willing to pay this cost so instead resort to using denatured ethanol or get their ethanol from a hardware store. This denatured ethanol contains up to 5% of dangerous chemicals such as benzene, toluene, or heptane. It is then up to the processor to ensure that the chemicals used for denaturing the ethanol are properly removed from the extract. Most processors don’t have the equipment to properly remove them or the testing equipment to ensure that they have been properly removed from products. Hydrocarbon extraction is an even worse option as instead of 5% of the solvent being dangerous it is using 100% butane as the extraction solvent. If any residual butane is left behind in the product then it can be a health risk to consumers. The reason that most companies utilize either ethanol or hydrocarbon extraction is due to the low cost and barrier to entry of those two technologies. Supercritical CO2 extraction costs significantly more upfront but has a lower backend cost due to the low cost of CO2 and the ability to capture and reuse CO2 after each run. This high initial barrier to entry though drives most processors to choose cryo-ethanol or hydrocarbon systems for their extraction plant and the high backend costs of these methods cause them to cut corners in the quality of solvent that they are using or not testing batches of extract for residual solvents. This can cause a significant health concern for consumers of products made from extract that was extracted by either of these methods.
Dr. Ryan J. McKinnie
Chief Scientific Officer
Commonwealth Extracts LLC.
6900 Riverport Dr.
Louisville, KY 40258