Method and apparatus for extraction of oil from plants

A distillation method in a system comprising a pump, the method comprising:

• draining a solvent-oil mixture from a reaction chamber into a distillation column;
• distilling the solvent-oil mixture in the distillation column;
• triggering a dual vapor recovery process from the distillation column as a result of attaining a first pressure differential between the distillation column and any one of a plurality of solvent tanks, each of the solvent tanks coupled to provide solvent to the reaction chamber;
• the dual vapor recovery process comprising:
• (a) opening a first vapor valve between the distillation column and a condenser;
• (b) opening a first solvent valve between the condenser and a first solvent tank meeting the first pressure differential;
• (c) using the first pressure differential to move vapor out of a headspace of the distillation column into the condenser without the use of the pump;
• (d) concurrently with (c) and on condition that the pump is not already in use to pump solvent:
• selectively activating the pump and opening a second vapor valve between the distillation column and a second solvent tank;
• pumping vapor from the headspace of the distillation column into the second solvent tank with the pump;
• (e) while (c) and (d) are underway:
• selectively opening a second solvent valve between the second solvent tank and the reaction chamber, once the pressure in the second solvent tank causes a second pressure differential sufficient to move solvent from the second solvent tank into the reaction chamber.