CBD oilCBD is an abbreviation for cannabidiol. This chemical compound is derived from the cannabis plant. CBD oil is useful for the treatment of numerous medical conditions. You can find CBD oil in products such as edibles, creams, and oils. There are three main extraction methods for CBD. These are carbon dioxide extraction, steam distillation, and solvent extraction. All of these methods are described in detail below.


Carbon Dioxide Extraction


Carbon dioxide extraction is often referred to as CO2 extraction. When CO2 is at standard pressure and temperature such as places where special equipment is not required for people to survive, carbon dioxide generally behaves like a gas. It does not require a lot of effort to change this gas into a solid. The solid-state is referred to as dry ice. The machine used basically freezes the CO2 so it can be compressed into a gas. The resulting cold liquid state is referred to as supercritical. These are the two most often seen phases of carbon dioxide outside of a laboratory.

CO2 gas can be transformed into a liquid by using special equipment. The pressure is increased to 75 pounds for each square inch. The temperature must remain below -69 degrees Fahrenheit. The liquid carbon dioxide is where the process used for CO2 extraction begins. Once the CO2 is in a liquid state, the pressure and temperature are both increased past a specific point. The numbers required to make this happen are extremely complicated. The point is, once the pressure and temperature of the liquid carbon dioxide have been increased, the fluid enters the supercritical state.

This means properties can be adopted simultaneously while the CO2 is between a liquid and a gas. A container can be filled with a supercritical fluid in the same way as with a liquid or a gas at the same time. Even though the container has been filled with a supercritical fluid in exactly the same way as gas, the fluid can maintain the same density as a liquid. The supercritical property of carbon dioxide is ideal for chemical extraction. This is because CO2 is gentler than any of the other compounds. It will not cause denaturing or damage making the product unfit for consumption.

The solubility of carbon dioxide varies according to the pressure. This means only a few little adjustments are necessary for extracting selected compounds using supercritical CO2 as opposed to using a combination of numerous different compounds. The actual process begins with liquid CO2. The pressure of the liquid carbon dioxide is increased using a compressor. A heater is then used to increase the temperature. A high-grade pot is used to pass the supercritical CO2 through. The pot is contained within an extractor.

At this time, all of the essential waxes, terpene oils and trichomes are pulled out of the plant material through the carbon dioxide. The solution is the supercritical carbon dioxide containing all of the desirable materials from the plant. This is broken down by passing through a separator into all of the constituent parts. The beneficial materials including the terpenes and trichomes are then sent to a receptacle for collection. A condenser is used for passing the supercritical CO2 through to turn it back into liquid form. The liquid is sent to a tank for storage so it can be used to begin the same process again.

There is no residual carbon dioxide leftover in the extract. This is because once the process of extraction has reached completion, the pressure has been decreased on the CO2. This enables the liquid molecules of CO2 to resume the form of a gas. They can then evaporate right into the atmosphere. This is the easiest part of the entire procedure. The extracts simply need to be left at room temperature. This is the same chemical reaction resulting in your soft drink becoming flat once it has warmed up after being opened.

There are certain industrial supercritical machines capable of making the process even simpler. Once the extraction has been completed, the machine recycles, reuses and recaptures the CO2 gases. Just like with every extraction method, there are pros and cons. The pros include:

• Unlike the solvents used for the other extraction methods, CO2 is not flammable.
• When CO2 is used, the extracted CBD is not a toxic residue.
• CO2 is ideal when using substances and materials requiring a specific temperature.
• Due to the closed-loop process used for CO2, the carbon dioxide is reusable.

The cons include:

• Expensive equipment and special training are required for CO2 extraction.
• The process of CO2 extraction is unable to be consistently repeated. This is because the equipment and materials used for each extraction session must be treated and sterilized after each use.

Steam Distillation


Steam distillation begins by heating up water. Once the water is heated, the steam will move in an upward direction into the flask. This is how the oil vapors containing CBD are separated. A tube is used to capture the vapors so they can be condensed into water and oil. After being collected, the mixture of water and oil is distilled so the CBD oil can be extracted from the water. The technique used for steam distillation has been used for the extraction of essential oils for centuries. Despite, this the method is still far less efficient than CO2 extraction. The Pros for this method include:

• Anyone with access to basic chemistry equipment and a lot of hemps can use steam distillation at home.

The cons include:

• The process is completely inefficient since many of the oils are not extracted from the plant material.

• Due to the availability of high-quality commercial CBD products, steam distillation is not worth the time to perform at home.

• A lot more plant material is required to produce the same amount of CBD oil.

• The terpenes can be damaged by the high heat necessary for this method.

• Extracting specific amounts of CBD is very difficult with this method.

• Steam distillation is risky if the steam is allowed to become too hot. This can change the cannabinoid's chemical properties and cause damage to the extract.

Solvent Extraction


There are several types of solvents used for this type of extraction including natural solvents and hydrocarbons. Propane, butane and any combination of the two are popular solvents due to their low boiling points. This enables the essence of cannabis to be captured by the extractors. This is accomplished by dissolving the resin gland heads so the plant matter and terpenes can be pulled out without the use of extreme temperatures or pressure. Propane and butane usually require between fifty and 150 PSI of pressure.

Since these solvents have a low boiling point, the extraction of the required materials can be accomplished without the risk of the terpenes or cannabinoids being damaged by the heat. The boiling point of butane is 30.2 degrees Fahrenheit where propane requires -43.6 degrees Fahrenheit. This is important because one of the common elements in cannabis is terpene. The boiling point for the terpene found in most varieties of cannabis is between 331 and 334 degrees Fahrenheit. The boiling point of delta 9-THC is 314.6 degrees Fahrenheit.

Moderate scale operators are processing fewer than 1,000 pounds of biomass each day. Just like the artisanal extractors, they use the technology of propane extraction. This yields a product with the smell of rich terpenes and a light color. The problem is using a butane system is expensive. This is because additional safety precautions are required for the larger systems to prevent the escape of flammable gases. This places the employees and facilities at risk. The location must be a class one division with standards for 1 hazardous.

The boiling point for ethanol is low just like for propane and gas. This is 173 degrees Fahrenheit. The difference is no pressure is necessary for extracting the compounds from the plant. Ethanol is less flammable than either propane or butane. Ethanol is safer to use for employees working in an urban or industrial environment. The fact the boiling point of ethanol is slightly higher means products must be distilled or decarboxylated to make certain the final product does not contain any residual solvents.

Another difference between ethanol, propane, and butane is unlike the other two, ethanal is a polar protic. This means the molecular charge is positive. This is what enables ethanol to bind so well with terpenes and cannabinoids in addition to unwanted compounds including water-soluble compounds, chlorophylls, waxes, and fats. Not only can this have a negative impact on the equipment but it can also damage the quality of the product.

The smaller scale operators have discovered a way to subvert this issue. The ethanol is simply chilled to -40 degrees Fahrenheit. This leaves the majority of the unnecessary chlorophylls, waxes, and fats behind. The pros of solvent extraction include:

• Organic solvents can be used for commercial extraction because they are safe.
• Organic solvents will not harm the environment.
• An extraction using organic solvents is an efficient method for cannabis extraction.
• The products produced with organic solvents are safe to enjoy and consume.
• Organic solvents produce a final product with a nice taste.

The cons include:

• The boiling point of ethanol is a lot higher than either propane or butane. This means the recovery process is more difficult and much slower.

• Ethanol requires a post-processing extraction process requiring a lot more labor than a hydrocarbon. This requires several different methods for filtration and refinement.

• The products that can be produced using ethanol are limited. It is almost impossible to produce items including sauce or shatter.

The Reasons CO2 Extraction is the Best Method

As more research is conducted and technology continues to advance, extracting CBD from plant material is expected to become even more efficient. The most widely used and advanced extraction method is currently CO2 extraction. This is considered the best extraction method for numerous products including CBD oil. Every mammal on the planet creates carbon dioxide every time they exhale. The type of food you eat enables you to consume energy while simply breathing the air provides you with oxygen. The energy created by your cells creates a by-product of both carbon dioxide and water.

Once you have created the essential nutrients, you exhale carbon dioxide. The two most typical forms of CO2 extraction are supercritical and subcritical. When a subcritical CO2 extraction is used to manufacture a product, you will see the method listed on the label. The supercritical CO2 extraction is also listed. This is when CO2 is used for extraction with a pressure of 1083 PSI and a temperature of 88 degrees Fahrenheit. When the pressure and temperature conditions are extreme, the molecules extracted must have a higher weight and character.

This is more efficient because it enables the extraction of molecules from the plant left behind by the other methods. Unlike some of the chemicals required for the other methods, there is more than enough CO2 available. This enabled the researchers and manufacturers to become extremely creative in the way they use CO2 for extraction purposes. Through the use of different tools, heat and CO2, very powerful and extremely pure CBD products are being produced by the manufacturers. Carbon dioxide extractions are much cleaner because they do not require any chemical solvents.

CO2 extractions result in more cannabinoids being drawn from the hemp plant. As the extraction techniques continue to improve, even more, will be harnassed from the plant. CO2 extractions have no significant drawbacks. Yes, specialized equipment is necessary because the procedure is mechanical but the oil obtained is food grade and the CO2 is safe. Due to the effectiveness of the CO2 extraction at removing oils and aromatics from the hemp plant, there is a lot less waste. The cost is less because extracting the oils requires less energy.

All of this means CO2 extraction is a lot more friendly to the environment. For anyone who cares about what is being put into their bodies and the environment, the only real choice is carbon dioxide extraction