March 28, 2019

Vincent continues to experience high demand for screw presses for solvent and oil recovery in hemp processing. Over the past twenty-four months we’ve seen a gradual shift from Lab Size equipment to Pilot Plant operations. We are now quoting industrial scale processing facilities with 200,000 pounds per day requirements for 2020. In addition to these larger projects, we continue to be a go-to solution for the smaller operators, with over forty screw presses, capable of 100 to 350 lbs/hr, ordered in the past six weeks.

A majority of our presses are used in the CBD and THC extraction process. Many types of extraction are currently being used: “hydrocarbon” (typically butane or propane), supercritical CO2, coconut or olive oil, ethanol (alcohol), and even hexane or heptane. Hydrocarbon and supercritical CO2 are primarily used for THC production as they give a much better terpene profile and associated flavor. Ethanol extraction, which only really entered the scene two years ago, has quickly become the mainstream, cost effective strategy for processors of all sizes.

When processing hemp for CBD oil, it is first dried and then soaked in ethanol. A typical mix would be 300 gallons per 1000 pounds of biomass. In the early days Vincent screw presses were used primarily for recovering additional solvent and oil following this initial wash. Free run solvent was either allowed to drain off, or was spun out in a centrifuge. In this application an additional 20% – 30% of solvent and oils is recovered. Our screw presses quickly pay for themselves with as much as 325 gallons being recovered from every 10,000 pounds of spent hemp. Ethanol represents the largest operating expense of a processor, especially when using 200 proof (because of the Federal Excise Tax.).

Press liquor expelled by the screw press goes through a winterization or de-fatting process. This removes suspended solids, waxes, lipids, and fines. We are aware of customers doing this at -80C to as high as ambient temperature.

Traditionally this has been a batch mode process. We are currently working with apparatus innovators who have brought continuous processing de-fatting equipment to market which can handle 3K, 5K and 15K liters per hour.

Diatomaceous earth or activated charcoal filtration can be used to remove chlorophyll and other impurities.

Finally, the liquor will go through an alcohol reclamation process to recover ethanol which is re-used upstream on fresh plant material. Typical equipment used for this purpose includes Rotovaps, falling film column evaporators as well as traditional ‘stills’. In general processors should anticipate a 92% recovery rate of ethanol through this processing. The technology around these operations is evolving quickly, with much theory borrowed from the flavor and fragrance industries.

At this point of the processing cycle, Vincent equipment has done its job and has given processors their valuable crude oil. This oil contains as much as 60% of the pure CBD Oil they are going after. Typically this crude will go through a short path fractional distillation or wiped thin-film evaporators.

At the other end of the process, on the farm, in 2018 Vincent spear-headed the use of alfalfa screw presses. These were used, at harvest, for removing excess water (juice) from fresh forage chopped hemp. The results have been significant, with the removal of up to 40% by weight as press liquor, with negligible CBD oil loss. Physical volume is reduced by up to 50%, with drying time being reduced by 2.5x. Over the past month we have received multiple orders for presses capable of running up to two acres per hour for this application. The drying process represents the biggest bottleneck and capital expense at harvest.

Vincent is proud to be participating in the introduction of efficient, high throughput, continuous processing capabilities to a maturing hemp industry.

Issue #313