Pros & Cons of Ethanol Extraction


Precision Team


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    Not All Solvents Are Created Equal

    In a maturing extraction industry, many companies have released new technologies promising to be the “next best thing”. What you probably won’t find alongside these tall tales of massive throughput is the story of the science, and why each method has its limitations and benefits.

    In this article, we will take a closer look at cannabis ethanol extraction vs hydrocarbon extraction for mid-scale operations (200-1000 lb of processing input material per day, in hemp or traditional cannabis).

    The Science of Cannabis Extraction

    The solvent (ethanol or hydrocarbon) is passed over the plant material in order to dissolve the active compounds in the plant, in this case the cannabinoids and terpenes, but not all solvents are equal. Because ethanol is what is called a “polar” solvent, it will be more hydrotropic, meaning it will want to bind to the water soluble components of the plant. The result is a less pure, generally less potent end product that needs more post processing (the general exception to this is when making full spectrum hemp extracts, because it has been proven that some water soluble components of the hemp plant actually have health benefits).  With hydrocarbon, the solvent is non-polar, meaning it binds to the more fat soluble components of the plant (cannabinoids and terpenes only). The result is a higher purity extract at the end of the primary extraction.

    Ethanol extraction proponents would argue that most of the water soluble plant component extraction can be circumvented by keeping very cold temps below -5 °F, and this is true, to an extent, and also herein lies the problem.

    In the developing cannabis and hemp markets, all the craze, and the hottest products are now revolving around “The Sauce” (HTFSE) and isolates/crystals. Simply put, an isolate is a crystalline structure of a single molecule, normally THC-a or CBD cannabinoids, with certain products like “The Sauce” also adding a terpene layer into the mix.

    To make such products, you generally need an initial extract purity greater than 80%, particularly in the case of CBD crystalline but this is also the case in scenarios of THC-A crystalline. Because of its polar nature of ethanol as a solvent for primary extraction almost never reaches such concentrations of purity and therefore has its limitation in making a less pure, full spectrum type hemp extract (which has a bustling market of its own).

    Ethanol Cannabis Extract

    Ethanol proponents would say that their primary extract could be crystalized by further purification or downstream processing, and they would be right. What they won’t tell you is that the purification process in order to make crystalline is labor intensive, costly, and very hard to scale. The process normally involves multiple stages of filtration, separation, chromatography, as well as solvents such as dimethalether, chloroform, and dichloromethane in some instances. However, on a large scale, such downstream processing makes perfect sense as massive amounts of hydrocarbon are hard to store, permit, or use in a continuous feed plant style operations. In addition, massive efficiencies are gained in ethanol post processing when brought to a large scale.

    There is an ongoing joke in the industry about the “Loch Ness Monster”… the ethanol extractor that has both amazing throughput and unparalleled purity. The problem: no one has ever seen it. Ethanol is a viable method of extraction and, like all other methods, it has its pros and cons.

    Pros of Ethanol Extraction

    • Storage limits are much more lenient with Ethanol allowing the facility to keep more storage in the facility while meeting fewer requirements allowing the user to extract large volumes of cannabis at once.
    • If done properly, Ethanol extraction can eliminate the need for a dewax or winterization.
    • Great for creating for full spectrum hemp extracts and tinctures.

    Cons of Ethanol Extraction

    • Ethanol is a polar solvent and will pull more water soluble components from the plant such as chlorophyll.
    • Ethanol has a much higher boiling point than Butane or Propane making the recovery process generally slower and more difficult.
    • Ethanol is limited in the products it can produce making items like shatter or “sauce” is nearly impossible.
    • Post processing for ethanol extraction is much more labor intensive than hydrocarbon and involves the use of several different methods of refinement and filtration.

    There is a solution for extraction operators who wish to utilize BOTH hydrocarbon and ethanol. At Precision, our MSE (Multi Solvent Extraction) systems can utilize butane, propane or ethanol solvents.

    For high volume, ethanol-only extraction we also offer centrifuge ethanol extractors.

    C-15E Centrifuge Ethanol Extractor
    • Designed for low to mid-scale volumes
    • Ethanol solvent only
    • Up to 15 lb per run every 10-20 minutes*
    • 98%+ cannabinoid removal
    • 97%+ ethanol solvent removal
    • Requires a single operator
    • C1D2 compliant

    View C-15E

    C-40 Centrifuge Ethanol Extractor
    • 2 configurations available – low temp & room temp
    • Ethanol solvent only
    • 98%+ cannabinoid removal
    • 97%+ ethanol solvent removal
    • Mid to large scale volumes
    • Safe to use, C1D2 compliant

    View C-40

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