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Petroleum‐free extraction of oil from soybeans with supercritical CO 2
Author(s) -
Friedrich J. P.,
List G. R.,
Heakin A. J.
Publication year - 1982
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02662228
Subject(s) - hexane , chemistry , extraction (chemistry) , supercritical fluid extraction , supercritical fluid , supercritical carbon dioxide , carbon dioxide , solubility , solvent , chromatography , refining (metallurgy) , toluene , organic chemistry
Full‐fat soyflakes are readily extracted with supercritical carbon dioxide (SC‐CO 2 ) at pressures of 3,000~10,000 psig and 50 C. Under these conditions, SC‐CO 2 has the density of a liquid and the diffusivity of a gas. Therefore, equilibrium solubility is readily achieved in a short‐path batch extractor which permits high gas flow rates. Soybean oil extracted with SC‐CO 2 is lighter in color and contains less iron and about one‐tenth the phosphorus of hexane‐extracted crude oil from the same beans. The lower phosphorus content is reflected in a chromatographic refining loss of 0.6% compared to 1.9% for hexane crude. Refined oils from hexane and SC‐CO 2 extraction had equivalent odor and flavor scores initially and after 4 days' storage at 60 C. Carbon dioxide, an ideal solvent for extraction of food products, is low‐cost and readily available from fermentation processes and could free over 20 million gallons of costly hexane per year for essential energy uses.