Carbon dioxide is an ideal chemical. It’s readily available, stable, low-cost, non-toxic and non-flammable. Its properties are easy to manipulate. Breathed out by humans, breathed in by plants and considered safe by the FDA, carbon dioxide (CO2) gets used in a variety of processes and products.

In the food industry, carbon dioxide extends the shelf-life of grocery items. It acts asa preservative, inhibiting the growth of yeast, bacteria and mold. CO2 provides the pleasant fizz in soft drinks, beers and hard ciders. There are also a variety of ways in which carbon dioxide is useful to the hemp industry.

Hemp crude oil extracted by carbon dioxide is fit for human consumption. This is because carbon dioxide does not denature the terpenes or cannabinoids. It’s also accessible for further refinement.

Chemical extraction is a good option for commercial-scale production of crude hemp oil. The process allows companies to maintain quality over time. It also helps produce higher volumes of product. CO2 extraction involves injecting carbon dioxide into large quantities of hemp biomass.

Supercritical extraction

Since it is a good solvent, liquid CO2 can safely remove caffeine from coffee. It can also remove cannabinoids and terpenes from hemp. Liquid carbon dioxide is only created at high pressures. This is why supercritical CO2 extraction is a job for commercial-scale machinery.

Carbon dioxide hits supercritical at a specific pressure and temperature. At a certain point past CO2’s critical point, you get supercritical carbon dioxide. In this phase, carbon dioxide can expand to fill a container, acting like a gas. Yet, it still has density, like a liquid. This mix of properties allows supercritical carbon dioxide to reach small pores liquids can’t.

Even as an extractor, supercritical carbon dioxide can mix with hemp biomass in a way that pulls out essential compounds. To prevent this, the carbon dioxide gets boiled out of the hemp biomass. It’s then condensed into liquid carbon dioxide for reuse in later extractions.

Subcritical extraction

Subcritical extraction uses pressure to keep carbon dioxide in its liquid form. This lets it act as a solvent above its boiling point. The process is also called accelerated solvent extraction (ASE) or pressurized solvent extraction (PSE).

Subcritical extraction of hemp crude oil produces a lighter-colored extract. It contains more volatile oils, but fewer resins and waxes. This process produces a lower yield. It takes longer to complete than a supercritical extraction process.

Subcritical extraction is able to remove terpenes and essential oils without damage. However, this method is not able to extract larger compounds, such as omega-3, omega-6 and chlorophyll.

Mid-critical extraction

Mid-critical extraction is less commonly discussed; it occurs between supercritical and subcritical states. This form of extraction is gentler, especially when compared to supercritical extraction. It doesn’t pull out some of the larger molecules that go unused. You can use oil created from this process to create an amalgamated, “full-spectrum,” oil. This occurs when you combine oils from different extraction
processes. The CBD created contains other cannabinoids.

Refinement options

Hemp crude oil has a large range of plant compounds in it. This includes essential oils along with various cannabinoids. You sometimes even get low levels of THC. Once CO2 extraction is complete, crude oil can get refined even further into products such as:

• CBD Distillate, with a typical CBD content of 80 percent. Trace levels of THC may also be present, along with CBC, CBG and CBN. CBD distillate often
  presents as a viscous liquid. It can also crystalize into a rock-like consistency.
• CBD Crude Isolate, with a typical CBD content of 99.9 percent. It does not contain any THC or extra cannabinoids. This is Cannabidiol in its purest form, and is most often used in vape juice.

Superior extraction services

For all your extraction needs, it’s best to work with a knowledgeable and reputable company. At Arbor Vita8, we pride ourselves on having the highest-quality extraction equipment. Our attention to detail, process and safety make us an excellent partner. We look forward to working with you in extracting the valuable materials from your hemp biomass. Contact us today to learn more.