Vacuum equipment is critical for the extraction process. Virtually every step in the process of converting plant matter to high purity oil relies on vacuum—including running a vacuum purge oven, filtering winterized extract, concentrating extract with a rotavap, and separating out products through techniques like fractional distillation. Working with the right vacuum lets you finish steps faster, more safely, and with better purity and potency.
There are a few critical factors that are must-haves with any vacuum equipment that you use. For example, finding a reliable pump is absolutely essential in every operation. Reliability means selecting a pump that you can count on to max out your production rate and one which saves you the cost in time and money of replacing your pump on a regular basis. The value of product lost from every hour of downtime makes this vital.
A related factor is the durability of the pump you choose. By selecting a pump that is made from chemical-resistant wetted components, you will not only reduce the maintenance on the pump, but you will see that the pump lasts quite a bit longer. Reducing maintenance also helps to keep your production high.
To get the best reliability and durability, talk with your vendor about maintenance requirements and pump lifetime. Whenever possible, use a dry pump rather than an oil-sealed pump. Dry pump technologies like diaphragm pumps can be constructed from chemical resistant wetted materials like fluoropolymers which hold up when exposed to solvents like ethanol. Dry pumps also eliminate the need for frequent oil changes. In some cases, it may be necessary to use an oil pump. In these situations, make sure that you use a cold trap or pre-condenser to keep chemicals out of the pump oil.
Beyond the Basics
The basic considerations of reliability and durability apply universally. But how do you get the “right” vacuum for a specific situation?
It varies from one operation to the next, and one process to the next. Since no two extraction processes are the same, the best solution depends upon your process parameters and your goals. Finishing the extraction process as fast as possible will require different operating parameters from maximizing throughput, for example.
Some key considerations for common steps in the extraction process include:
Purge Ovens: The right vacuum for your purge oven means that you can quickly evaporate off solvents like ethanol, water, and butane rapidly, and at a relatively low temperature to preserve product integrity. Look for a pump that offers high pumping speed in the range that the relevant solvents evaporate.
Filtering Winterized Extract: Filtering winterized extract fast is critical to prevent frozen fats and waxes from thawing. To make sure your filtrations go quickly, size your pump to provide enough flow for the size of your filtration. A Buchner funnel on the bench needs a smaller pump; a larger pump is needed for process-scale filtrations.
Concentrating Extract with a Rotary Evaporator: Running a rotavap and completing an evaporation process quickly without product loss requires precise vacuum control. So, using a vacuum pump combined with vacuum control is critical when concentrating extract. You can save further time by using a pump with built-in automation capabilities. This frees up the time of staff to attend to work that requires their attention without slowing down production. It also means that you get more repeatable results with every batch.
Separating Purer Fractions: Fractional distillation separates refined cannabinoid oils using relatively deep vacuum, typically on the order of 10-3 torr (0.001 torr), called the ‘fine’ vacuum range. Combined with fine vacuum control, you can separate purer fractions. Combining the deep vacuum with fine vacuum control yields purer, more potent products.
Don’t Forget Support and Service
Finding the right vacuum equipment that will optimize your process and maximize your profits is important. But equally important is having support when you need it. When you select a vendor, make sure that they have a product expert at the ready to help you. And be certain that they can provide you with repair and preventative maintenance service when you need it.
Each step in the extraction process has unique requirements. In order to reliably get the highest quality product at the highest production rate, vacuum equipment must be specified which accounts for these requirements. By using advanced control capabilities, vacuum parameters can be fine-tuned to further accelerate production and enhance yields. By working with a knowledgeable vendor, you will get high-quality, reliable equipment that will get the most out of your extraction process and enhance your profitability.
About the Author
Scott Leahy from VACUUBRAND has been helping clients optimize their processes by specifying the best vacuum equipment for their work. Scott works with a team of factory-trained experts who cover scientific vacuum applications that range from benchtop R&D to pilot production. VACUUBRAND has an array of chemical-resistant diaphragm pumps, compact rotary vane pumps, and intuitive controls for each step in the extraction process.