CBD – cannabidiol is usually produced by extraction from CBD-rich hemp plants. Extraction is a common separation process for getting valuable substance from any material. Solvent (usually liquid) is needed for any type of extraction.
Mostly used a solvent for extraction of CBD from hemp plants is some type of alcohol. However, there are also other solvents available. For example extraction by supercritical carbon dioxide - CO2.
Alcohol versus CO2
It is necessary to mention the basic differences between these two solvents. Let's start with alcohol. Alcohol has an origin in an organic material since it is mostly produced by the fermentation of plants. Contrary to CO2 which is a poisonous gas. 8-10% concentration of CO2 in the air causes nausea, unconsciousness and eventually death.
These are just the most obvious facts. More important for extraction is that CO2 extracts non-polar chemical bonds, while alcohol extracts both polar and non-polar chemical bonds.
Simply speaking, alcohol extracts more substances than CO2. And it applies to hemp plants as well. Alcohol is a solvent made from plants for plants.
CBD from alcohol extraction is better
As stated above (and in the resources bellow), alcohol extraction provides more complex extracts. And this is important especially for hemp plants since they contain a very broad range of various substances some of which are even unknown till today. Particularly substances are soluble in water, various oils, polysaccharides, acids, etc.
Water soluble substances are very important since the human organism is made from 70% of water and it makes these substances easier to absorb. CO2 extraction thus misses many valuable compounds that are hidden in hemp.
CBD and its absorption
Another important thing about alcohol extraction is the esterification of organic acids. Esterification happens when organic acids (for example CBDa and other acid forms of cannabinoids) react with alcohol. Produced esters are soluble in water, making extract easier to absorb into the human body.
In other words, CBD extracted by alcohol is more bioavailable and thus has greater medical potential.
Resources:
http://www.cbd-hemp-oil-drops.com/
http://www.cbd-hanfol.eu/
http://www.evolvedalchemy.com/co2-vs-alcohol-extractions/
https://en.wikipedia.org/wiki/Chemical_polarity
https://en.wikipedia.org/wiki/Carboxylic_acid
