CO2 and Butane (BHO) Cannabinoid Extraction Technology for Medical Cannabis Concentrates

CO2 and Butane (BHO) Cannabinoid Extraction Technology for Medical Cannabis Concentrates

Cannabinoid extraction using CO2 technology

Cannabinoid extraction method using CO2 begins with Cannabis resin glands (trichomes) freezing, to make them easy to loosen from foliage and reserve glands/trichomes potency levels or in milled cannabis material. One of the unique things about the CO2 method, is that other plant material such as leaves can be used in the process.

Except for high initial costs for system purchasing and set up, the CO2 extraction method leaves no solvent residuals in the final product.  A proper set up CO2 extraction is considered to be very important in order to achieve an efficient extraction process. Every Cannabis strain includes different content of Cannabinoids and therefore require a different CO2 extraction program. Large CO2 scale extraction system function under high pressure and have precision tolerance to get the most out of the separation process.

CO2 extraction technology is considered to be a controlled, robust, scalable one and complies with GMP requirements and standards.

Two types of CO2 extraction methods- Supercritical Fluid and Dry Ice.

Supercritical CO2 extraction technology is characterized with high diffusion rate which allow faster solids penetration than a liquid solvent. Naturally occurring carbon dioxide that is being evaporated spontaneously from the final product and residuals solvents are not contained in the final product. In modern CO2 systems, the CO2 gas in being recirculated and used in the following extraction cycles.

Supercritical CO2 system:

The process begins with placing milled cannabis (flowers and/or leaves) into the extractor chamber. CO2is applied from gas tank/cylinders which flows in to the extractor.  A compressor is used in order to raise the pressure of the liquid CO2 and turn it in to supercritical CO2. Supercritical CO2 physical state is both liquid and gas and therefore is able to extract the essential cannabinoids, trichomes and terpene oils and/or waxes out of the plant material. The extracted substance is then passed to a separator. The heavy extract sinks to the bottom of the extractor while the supercritical CO2 is passed through a condenser back into the liquid phase. The liquid CO2 is then pumped to the storage tank where it can be reused.

CO2 extraction method Pros:

  • Clean, less risk of residual solvents
  • Safe
  • Controlled and GMP compliant
  • Easy to put the final product in vapor pens
  • Often considered “solventless” and non-toxic (though CO2 is a solvent, it evaporates entirely)
  • More environmentally friendly (not a petroleum product)
  • Non-flammable material
  • Low running cost (electricity, gas etc.)

CO2 extraction method Cons:

  • Less terpenes concentration in the final product
  • High initial costs
  • Often considered as low product strength
  • Prolonged cycle time
  • Leaves extraction product contain high concentration of waxes

Cannabinoid extraction using Butane (BHO) Technology

Butane extraction technology is considered to be relatively inexpensive, easy to find, and very fast acting.

Butane extraction technology leaves heavy metal residues in the extracted resin.

Butane extraction technology is considered severely hazardous, especially if being used in non-industrial facilities and forbidden to be used in several states such as California. In order to use the BHO extraction technology, an explosion proof facility and equipment should be used.

Butane is very flammable and highly explosive (boiling point 0.5oC, flash point 60oC).

The Butane extraction method is considered non-GMP due to health risks associated with the solvent residuals, which may be present in the final product.

BHO system:


The process begins by placing milled material into the butane extraction tube. Butane, which is applied from gas tank/cylinders (is sprayed into the extractor chamber.  The extract cannabinoids, trichomes and terpene oils and/or waxes will drop out of the plant material to the bottom of the extractor. The bottom of this double boiler chamber is filled with water and is heated in order to evaporate the butane. A vacuum pump is used in order to evaporate the remaining butane.

Butane extraction method Pros: 

  • Greater terpene expression, truer to the strain
  • Wide variety of products available, with differing tastes, aroma and effects
  • Often considered as high product strength
  • Cost effective
  • Short cycle time

Butane extraction method Cons: 

  • Potentially more risk of residual solvents
  • Heavy metals
  • Most systems are non-GMP
  • Unsafe, flammable and explosive solvent
  • Less environmentally friendly (petroleum product)

Additionally the CO2 extraction method is a better extraction method for terpene extraction in cardamom (Beta-pinine, Cineole, linalool, alpha-terpinol and bornelole).

Using Propane at high pressure will enable an increase in the yield of the CO2 extraction process.

Butane is a “strong” solvent for extraction and can easily be incubated with the Cannabis plant material for too long, it can continue to pull out more and more polar compounds like chlorophyll. With some fine-tuning of the CO2 extraction process it can be avoided / eliminated in case process parameters were validated.

So fast extractions are possible with butane but little control of all the material is present, while CO2 can be tunable and therefore is able to collect all of the same material, just through a segmented process.

About Cannabis GxP consultancy

Cannabis GXP is an Israel-based consultancy firm working within the cannabis industry.

We are currently engaged in revolutionizing the world of cannabis and hemp cultivation, production and regulation, and are reaching out to growers and manufacturers across the world who wants to join this amazing ride.

We are proud to stand at the forefront of the GMP standards and regulation fields in Israel and worldwide.

Our team is compelled to spread the message of the importance of cannabis regulation and standardization as the world enters a new era of cannabis legislation.

We aim to position our clients with their best foot forward when it comes to anything and everything cannabis related.

We assist companies and growers with facility design, Quality Assurance, Good Practices (GAP/GMP/GLP/GDP), training, and dealing with local and global regulation. Cannabis GXP strives to assist our clients with the development, manufacture and distribution of pharma-grade cannabis products, with a strong emphasis on safety, efficacy, and professionalism.

Cannabis GXP is a subsidiary company of Bio-Chem Ltd. (2007) – a consultancy company for Pharmaceutical, Medical Devices, Cosmetics, and Supplements, based in Israel (

Some of our esteemed clients: Teva, Tikun Olam, J&J, Weizmann Institute of Science, BOL pharma, Seach, Nuuvera, Gamma-Cert, Cannabillis, Monsanto, Evogene, Collplant, Sigma-Aldrich, and many more.

Our Cannabis consultancy services include:

  •  Investigational Cannabis product development and clinical trials
  •  Cannabis growing & manufacturing facilities design
  •  Cannabis Quality Assurance & Good practices (GxP)
  •  Cannabis product manufacturing technology
  •  Cannabis product regulation & FDA/EU submission
  •  Novel Cannabis APIs and product delivery systems

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