January 15, 2021
We completed design, building, and commissioning of a turnkey hemp oil extraction plant in 2020. This work was accomplished in Plant Works Group, a new subsidiary of Vincent Corporation. The facility was built using generally known technology, but with improvements which came to us from our experience in citrus oil extraction. Many components found in hemp oil are the same as with citrus oils. The result has been to leapfrog the cost and efficiency of competing facilities.
The Vincent plant uses a Model CP-6VT screw press as a primary extractor to process 350 pounds per hour of dried hemp. This process starts in a surge hopper which feeds and meters into a reaction conveyor ahead of the press. In the reaction conveyor the trichome oils are diffused into chilled ethanol. Vincent supplied everything including the ammonia refrigeration plant.
The solvent used is conventional 200 proof ethanol, denatured with 5% heptane added to make the alcohol unsuitable for human consumption. Normally alcohol is added to the hemp in a ratio determined by CBD content. Throughout the entire process this alcohol remains chilled to minimize the solubility of undesirable fats and waxes.
The dosing alcohol goes through a set of tubular heat exchangers where it is chilled ahead of the reaction conveyor. The oil-saturated alcohol expelled by the screw press is kept chilled. Hemp fibers are screened from the ethanol using proprietary technology which we developed. In this same process, any waxes which make it through are removed as well.
The process next uses activated carbon filtration to remove the chlorophyll.
A key part is the most expensive individual piece of equipment, a three effect, four stage steam-driven evaporator. In this evaporator we separate the cannabinoid oil from the alcohol. This alcohol is pumped to storage tanks to be re-used in the extraction process.
The next step is in the decarboxylation (decarb) reactor. Here the naturally formed acid cannabinoid oils are converted to their active forms. CBD crude oil is the finished product
A sophisticated control system was included with the project. For example, the main control cabinet held nineteen different VFD’s with ten PLC expansion cards. Multiple control loops and data logging capabilities were included.
Previously oil extraction was done in a laboratory batch fashion. Doing it on a continuous flow was the real challenge. Our familiarity with industrial processing of orange juice concentrate and essential oil recovery guided design and selection of many components.
Here is a link to a video showing the system:
HEMP OIL PRODUCTION PLANT video link – https://youtu.be/XK9czuUnqWM
There is still residual alcohol in the pressed fiber separated by the screw press. To recover this alcohol, Vincent has engineered a DT (desolventizer-toaster) unit. Steam is used to separate the alcohol, with some oils, from the fiber. These are being offered to existing hemp oil producers to meet EPA regulations covering waste disposal.
ISSUE #331