GB758768A - Improvements in or relating to processes of preparing vegetable oil bearing materialfor solvent extractions - Google Patents

Abstract

A vegetable oil-bearing material is prepared for solvent extraction by heating the material to 140-235 DEG F., adjusting the moisture content to 10-26 per cent in the early stages of the heating and reducing the moisture content in the latter stages of the heating, continuing the heating until the oil is easily extractable and the fine particles agglomerated, and finally reducing the temperature with further reduction of moisture content to cause the material to assume a crisp condition. The first stage of conditioning the material with adjustment of moisture content is effected at a temperature between 140 DEG and 210 DEG F., the succeeding reduction of moisture content is effected above this temperature at not more than 235 DEG F. In the first reduction in moisture content, the content is reduced below 18 per cent and in the final stages preferably to between 6 and 12 per cent. The moisture content may be adjusted by spraying with water, steaming, &c. The cooked materials are crisped by exposure to a cool atmosphere, conducive to evaporation of moisture, until the temperature falls below 160 DEG F. The vegetable material may comprise seeds of high oil content such as cottonseed, flaxseed and many other listed, seeds of low oil content such as soya beans and others listed, and also materials other than seeds such as rice bran, tung nuts and others listed. The vegetable material may be prepared for treatment in flake or particle form of dimension mainly not over 0.016 inches. The crisp material may be screened through no larger than a four mesh screen and the particles retained thereon are reduced in size. The so prepared material is then mixed with a solvent to form a slurry, the slurry is filtered to form a cake, the cake and further solvent are again mixed and filtered and the mixing and filtering are repeated a number of times, preferably in countercurrent using solvents containing successively small proportions of oil. The solvents specified comprise hexanes, e.g. methyl pentanes, and trichlorethylene. A continuous horizontal rotary vacuum filter with a number of spaces may be used.