Carbon Dioxide (CO2) is used in both the growing and processing of hemp & cannabis. Let's distinguish between the two and discuss how CO2 can benefit the process.
It is a misconeption that hemp and marijuana are two different plant species. They are actually not a different species but rather different names for cannabis. Even though scientifically they are not different, legally there is a differentiation. The main difference is in the amount of tetrahydrocannabinol (THC) content in each. For a technical look at THC visit the National Center for Biotechnology Information, U.S. National Library of Medicine's website. Hemp contains 0.3 percent or less THC content by dry weight. Marijuanna, on the otherhand contains more than 0.3 percent THC by dry weight.
One other difference to note is the 2018 Farm Bill made it legal to grow hemp throughout the United States. Cannabis containing more than 0.3% THC is illegal to grow federally, although State laws vary.
Carbon dioxide (CO2) is currently used in two way:
In indoor cultivation, co2 enrichment can increase yields by 50% or more. As germination takes place and the plants move into the vegetative stage, the plant consumes relatively little CO2 but benefits from the introduction of 600 - 800ppm of CO2 enrichment. In the flowering or "bud" stage, the plants benefit from the increased introduction of CO2 at a rate of 1,200 - 1,500ppm of CO2 enrichment. The highest levels of CO2 enrichment are most important in the final two weeks before harvest.
There are a variety of CO2 disbursement methods as well as CO2 controllers that can be employed. Safety is paramount and CO2 monitoring must be used.
Another use of carbon dioxide (CO2) is in the extraction industry. Supercritical extraction is the process of separating one component from another using a supercritical fluid as the extracting solvent. Typically used in the extraction of plant flavors and fragrances, it allows the processing of plant material at low temperatures, eliminating the degradation of the extract. By using a solvent like CO2, there is no toxic residual and the true nature of the plant is retained.
We shared with permission a blog post from Michigan Hemp Solutions on the use of CO2 in cannabis extraction on our website.
Information from this post includes the following:
CO2 readily evaporates from the oil leaving no residue once the oil reaches atmospheric conditions. CO2’s evaporation and terpene preservation leads to a natural tasting product and a golden color oil. Running supercritical or liquid CO2 (subcritical) through raw material also kills most microbial contaminants. Ultimately CO2’s ability to be fluid and ever changing allows us to stay ahead of the markets needs by meeting your need for broad-spectrum, green and clean oil!
CO2 extraction is ideal for cannabis as well as food, pharmaceutical, and fragrance industries due to its ability to process in a delicate manor. Settings such as temperature, and pressure ensures that we will not damage frail trichomes when performed correctly. Cannabis concentrates are targeted for an assortment of cannabinoids, terpenes and other components of the dried cannabis plant. Our goal at MHS is to be consistent and efficent in achieving therapeutic results. Current studies have suggested that extracting terpenes can enhance the medicinal effects of CBD along with other cannabinoids. The proper extraction of terpenes from specific strains allows us to satisfy medicinal market demands. If you cultivated a variety based on the medicinal value of that plant we are able to preserve and prevent those terpenes from getting lost in the extraction method. Consumers will be able to measure the quality based on effects upon consumption.