CO2 extraction, SFE build ideas?

I'm wanting to build a SFE co2 extraction "plant" home or garage unit...i am trying to use it with essential oil extraction projects...especially with cedarwood ( i have a successful steam distillation business, distilling and fractionating cedarwood oil and blending it with various carriers to provide my cedar based pesticides and lawn care products)...but i want to increase efficiency and potency, etc.

the USDA did testing with cedar and co2 SFE and had great success.

i am trying to build a unit...many ideas out there...but very few clear details, videos, pictures, etc...

i want to use for cedar, algae, kelp, bamboo, etc....various essential oil products...

the sad thing is i can find vague info from either large commercial units or from cannabis users...

IDEA's ?!?!?!?!?

FoolishSage4 years ago
I've worked with a small Supercritical CO2 unit to extract tannins out of cork. I didn't build it myself but maybe I can provide some insight into what you need.

I take it you know how supercritical extraction works so i'll focus more on the equipment itself. Keep in mind that you are working with high pressures so everything need to be properly rated. A loose bolt with 70 atmospheres behind it is not unlike a bullet. Also remember that while CO2 isn't toxic in itself it will push out oxygen and can therefore be extremely dangerous if not properly ventilated.

The unit I used had three stages:
-CO2 tank and pressure pumps
-Batch reactor under controlled temperature
-Outtake section and extraction trap

The first stage is a simple CO2 tank you can buy commercially attached to a system to bring it up to above 70 atmospheres. It is wise to have a pressure release valve on this system in case the pressure goes too high.

The second is a vessel which holds your samples and receives the CO2. Our reactor was placed inside a insulated box to keep the temperature steady (the box had its own temp regulation as well). The idea is to saturate the sample with the CO2. Once that is complete the CO2 supply is shut off and the outtake system is opened (slowly).

The outtake is done by opening the reactor to the atmosphere (slowly) past a trap. Once the CO2 drops below the critical pressure the extracted substances will drop out and drip into the trap as the CO2 returns to a gas and escapes the system. The temperature will drop strongly as the gas de-pressurises so be prepared to either do it very slowly or deal with the ice build-up.

I realise it is far from a step-by-step but maybe this information helped!