Patent attributes
A process and apparatus for extracting plant oil from plant material by cooling an alcohol solvent to a temperature of −40° C. or lower, contacting the plant material with the cold solvent to extract plant oil to provide a solvent and plant oil mixture, heating the mixture to convert the solvent to a gaseous state to thereby separate the solvent from the plant oil, and cooling the separated gaseous solvent to a liquid to recover the solvent. The apparatus may include a heat exchanger to cool the alcohol solvent, a centrifuge configured to receive and contact a batch of plant material with the cold solvent to extract oil from the plant material to provide a solvent and oil mixture, and a programmable logic controller to monitor and control the temperature of the cold solvent, and control the centrifuge to agitate the solvent in contact with the plant material.