Chromatography is one of the most popular methods for removing THC from hemp. Ultrafast chromatography is the most commonly used type, and it can achieve a 99.9% elimination of THC. However, it is expensive, which can be a deterrent for some. Dry screening, water extraction, and press extraction with rosin are all solvent-free methods that have been around for a while.
These processes are simple, but they lack coverage in the literature due to their outdated techniques and difficulty scaling. Dry sieve extraction produces a Kief powder with a potency of around 35-50% THC. This process begins by hitting the dried cannabis against a mesh to separate and detach the trichomes. The final product can be further pressed to make hashish or mixed with dried flowers.
This procedure is time- and labor-intensive, so it is not popular on an industrial level. Water extraction produces a similar THC potency as dry sieving, but it depends on the strength of the starting material. This process starts by placing the cannabis plant in a mesh bag, submerging it in ice water, and then removing it to remove the trichomes. The trichomes are then filtered through several filters before being allowed to sit and collect and dry the final product, which is commonly known as water hashish or bubble hashish.
When it comes to THC remediation, dilution and chromatography techniques can produce up to 99% CBD concentrations. Prolonged high temperatures can accentuate the degradation pathway from THCA to THC and eventually to CBN, resulting in high levels of THC and CBN. Chemical conversions enter an almost legal space since THC is illegal and CBN can be considered an “illegal analog” of THC in the United States. For hemp processors who want to manufacture CBD products with undetectable levels of THC, THC remediation technology ensures that hemp extract complies with federal and state laws.
New techniques are being developed that use the natural degradation process of THC to convert intoxicating cannabinoids into valuable ones. Since THC and CBD have similar boiling points, it can be difficult to separate them from each other. However, with the right techniques and processes, it is possible to remove THC from hemp without compromising its quality.