Patent ID: 6589422
Filing Date: 2003-07-08
Classification: B01D

Abstract:
Apparatus for extracting biomass from a liquid biomass supply, the apparatus comprising:a hollow vessel containing a liquid, liquid or liquid-entrained biomass being supplied at or near a first side of the vessel and a liquid solvent being supplied at or near a second, opposite side of the vessel such that a stream of solvent passes in one direction through the vessel and a stream of biomass passes as a countercurrent through the vessel, and such that biomass extract becomes entrained with the solvent; an outlet for biomass at or near the second side of the vessel; an outlet for solvent/extract mixture at or near the first side of the vessel; and a separator connected to the solvent/extract outlet for separating solvent and extract from one another, wherein the separator includes a rectifier for rectifying the solvent and separating therefrom the extract, a compressor, and a condenser connected in series, whereby the separator generates substantially uncontaminated solvent in liquid form; wherein the condenser includes first and second condenser stages connected in series, the second condenser stage operating at a lower temperature than the first stage and both condenser stages supplying substantially uncontaminated solvent to the hollow vessel; and wherein the second condenser stage includes a vent for venting uncondensed vapour therefrom, and wherein the vent is connected to an adsorbent filter that adsorbs solvent in the vented vapour.