Extraction of coniferous woods with fluid carbon dioxide and other supercritical fluids
AssigneeChampion International Corporation
InventorHenry A. Fremont
Life of this patent
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Abstract
Disclosed is a process for extraction of coniferous woods, such as pine, with supercritical fluids to recover tall oil and turpentine, or components thereof. Gases such as carbon dioxide, nitrous oxide, nitrogen, and lower alkanes or lower alkenes at temperatures above critical and pressures of about 100 psi above critical; i.e., supercritical fluids, are contacted with subdivided wood. The extracted wood is suitable for pulping and subsequent papermaking. The extract-bearing fluid is preferably stripped of the extracts by reducing the pressure in stages, each pressure reduction effecting removal of extracts of a narrowly-defined molecular weight range. The fluid is recompressed and recycled.
Claims9
A process for extracting tall oil and turpentine or components thereof from a coniferous wood which comprises:
- (a) subdividing a coniferous wood;
- and
- (b) contacting the subdivided coniferous wood with carbon dioxide maintained at a temperature above its critical temperature and a pressure of from about 50 to 250 psi greater than its critical pressure, for a period of time sufficient to extract the major portion of the turpentine and tall oil or components thereof.
Dependencies are inferred from the claim text.