We receive questions on a variety of subjects within the field of cannabis extraction, even a few outside of the topic. That’s why we created our popular Ask Vitalis series, but sometimes we just can’t quite fit them all in. Here are the most common questions we’ve been asked about our Q-Series Dual Solvent System and R-Series Dual Solvent System (formerly known as the Cosolvent Injection System or Vitalis CIS).

What is dual solvent extraction?

Dual solvent extraction allows you to use the best of what CO2-only extraction and ethanol-only extraction have to offer. Combined, they create a new extraction solvent that has better selectivity and faster extraction rates while retaining the quality of CO2 extraction.

How does the dual solvent extraction system work?

The CO2 solvent stream has 190-200 proof ethanol injected into it, altering the solvent environment to be more inviting from the perspective of the target compounds, which provides a more efficient extraction process. The extract, of which the ethanol is now a component, is then automatically moved from the cyclones to a dedicated collection vessel. The extract is then drained into the extract transfer tanks and moved to the winterization process where the waxes and ethanol are removed.

What are the process benefits of the dual solvent extraction system?

The benefits of the dual solvent extraction system are decreased extraction times, improved winterization processes, and lower overall operating pressures. The new process also gives you a more repeatable and accurate process of extraction, a reduction in operating costs due to the increase in throughput in a much shorter time, and a reduction in overall use of ethanol as less is required in the winterization process.

How long did it take to design and engineer the dual solvent extraction system?

The Vitalis team, comprised of engineers and scientists, worked hard for over 12 months to bring the new system to the market.

What was the most memorable experience you had developing the dual solvent extraction system?

When the science team was testing the in-house Alpha prototype, they received the first analytical results from the HPLC (High Performance Liquid Chromatography) instrument. Kiran, R&D team lead, got very excited.

Do you need a Vitalis Extraction System to use the dual solvent innovation?

Yes. The dual solvent extraction configuration has been specifically designed to be an optional part of Vitalis Extraction Systems, both the Q-series and the R-series.

What are the benefits of choosing the dual solvent configuration for a Vitalis Extraction System?

One advantage of the dual solvent option is that it’s designed to go with an already operational Vitalis Extraction system. For new systems, it’s a simple configuration option for our award-winning solutions. Other benefits of dual solvent extraction include increased throughput while maintaining extract quality.

What are the benefits of choosing dual solvent extraction if increased throughput is not the goal?

Greater throughput is not the only benefit of using dual solvent extraction. It can also help increase your overall business ROI by reducing production hours. Instead of running a 24/7 operation, you could run two 8-hour shifts, reducing labour costs and a variety of operational costs such as electricity. Another benefit of reducing your operational hours is no longer having to run overnight shifts, which could increase the overall mental health of your employees.

Will dual solvent extraction change the quality of the end product?

No. The advantage of using the dual solvent option with a Vitalis Extraction System is you can still run CO2 extraction only. Or, you can use the CO2 to get your terpenes and then use the cosolvent to grab your cannabinoids. Typically, you are adding ethanol when winterizing the oil after a CO2-only extraction, so you are still producing the same end product.

What is the approximate volume of ethanol use with a Vitalis Q90?

The ethanol volume required in dual solvent extraction depends on the biomass characteristics and extraction parameters. The more cannabinoids that need to be extracted, the larger the volume of ethanol that is required.

How many different industries does Vitalis currently work with?

Vitalis works in a variety of industries such as food and beverage and pharmaceuticals and many more coming in the future. However, to date, our dual solvent extraction field trials have been conducted for cannabis and hemp extraction only.

How long does a typical dual solvent extraction run take?

The average run-time for a Q-Series Dual Solvent System is 60 minutes, with a 24-hour throughput of 240 kg (529.1 lb). For an R-Series Dual Solvent System, the average run-time is 120 minutes, with a 24-hour throughput of 360 kg (793.6 lb). Those numbers are based on 80% cannabinoid recovery from a starting biomass of 10% potency. But throughput and run-times depend on a number of factors, and optimizing these is the key ingredient in achieving a good extraction:

  • Biomass characteristics
  • Mill size
  • Extraction pressure
  • Extraction temperature
  • Solvent flowrate
  • Recovery goals
  • Standard operating procedures (SOPs)

What would a typical extraction cycle look like with the dual solvent extraction system?

The dual solvent extraction process retains the benefits of CO2 (capturing terpenes, targeting desired cannabinoids) while leveraging the benefits of ethanol (increased speed). As well, winterization is improved since unwanted compounds usually found with conventional ethanol extractions remain in the raw material. In addition, instead of an alteration to the CO2 extraction operation, the system allows the flexibility to bypass ethanol injection when desired and allow for extractions using CO2 alone, as before.

Here is a simple outline of the extraction process:

  • An extraction vessel is filled with biomass.
  • Pressurized liquid or supercritical carbon dioxide is pushed into the extraction vessel.
  • Ethanol is injected into the CO2 solvent stream prior to the extraction vessel.
  • The carbon dioxide and ethanol dissolve the cannabinoids.
  • The cannabinoids are carried to a cyclonic separator.
  • The cannabinoids and ethanol are separated from the carbon dioxide.
  • The system is closed-loop, so the carbon dioxide rises out of the cyclonic separator to be re-used.
  • The cannabis extract descends to the bottom of the cyclonic separator.
  • The extract is automatically moved to a collection vessel and drained into transfer tanks to be taken for post-processing.
  • Following post-processing the extract can then be used in a number of end products.

What was the biggest roadblock when it came to bringing the dual solvent extraction system to market?

Time is always a factor when we carry out research and development. Science takes time, but with an industry need as great as this, it was important to get the dual solvent extraction system out into the market as soon as we could. Another challenge was the logistics during a global pandemic, particularly in obtaining materials for the research and development process, in shipping the products, and in safely sending our personnel to site for current installs.

What steps have been taken to ensure compatibility with hazard classifications?

The dual solvent extraction system has been designed to avoid the need to alter the room hazard classification, thereby allowing you to use this system in ‘non-hazardous’ areas.

To learn more about the process of dual solvent extraction, contact our team today.