Continuous extraction of oil-containing vegetable matter with pressurized normally gaseous solvent
First Claim
1. In a continuous method for extracting oil from communited oil-containing vegetable matter in which said vegetable matter is passed through a closed extraction zone in contact with a liquid extraction solvent medium wherein said extraction solvent medium is a normally gaseous hydrocarbon under a pressure in said extraction zone sufficient to liquify the same and up to about 250 psi, the improvement of continuously introducing said vegetable matter into said extraction zone for extraction therein by the steps comprising:
- advancing said vegetable matter through an elongated tubular screw-feeding zone communicating at its discharge end with one end of said extraction zone, subjecting said vegetable matter while within said screw-feeding zone to compacting pressure to create a region of compacted vegetable matter, and introducing under pressure into the compacted matter region for admixture with the compacted matter passing therethrough an innocuous normally liquid sealing medium, which if different from said oil is capable of being separated from the extracted oil, in an amount up to about 10% by weight of said compacted matter, and sufficient when mixed with the compacted matter to form the same into a generally plastic mass capable of sustaining the pressure in said extraction zone, the magnitude of said compacting pressure in the absence of said sealing medium being insufficient either to express said oil directly from said vegetable matter or to densify said matter to a solid dam of a density sufficient to contain the pressure in said extraction zone.
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Accused Products
Abstract
The oil in comminuted oil-containing vegetable matter is extracted by passing the vegetable matter through a closed extraction zone in contact preferably in countercurrent flow relation with a liquid extraction medium, which is a normally gaseous hydrocarbon, preferably propane, under a pressure sufficient to liquify the same up to about 250 psi, a temperature from about room temperature up to about 40°-50° C. and in sufficient volume to extract substantially the oil from such matter, e.g., a solvent feed ratio of about 1-3:1 by weight, the vegetable matter being continuously introduced into the zone by the steps comprising: advancing said vegetable matter through an elongated tubular screw-feeding stage communicating at its discharge end with one end of said extraction zone, subjecting said vegetable matter while within said screw-feeding stage to compacting pressure to create a region of compacted matter, and introducing under pressure into the compacted region a discrete innocuous normally liquid sealing medium which if different from said oil is capable of being at least substantially separated from the extracted oil, in an amount up to about 10% by weight of such matter which is effective to form the matter when compacted into a generally plastic mass, the magnitude of said compacting pressure in the absence of said medium being insufficient either to express said oil directly from said matter or densify said matter to a solid density capable of containing the pressure in the extraction zone. The preferred sealing medium upstream of the extraction zone is a recycled fraction of the extracted oil, and preferably a similar compaction zone is created in a screw-feeding stage at the discharge end of the extraction zone. The solvent and extracted oil are separated and recovered, the solvent being recycled for further extraction. The solid residue is freed of solvent and is useful, e.g., as defatted bran or meal. Preferably, the solvent-oil mixture after removal from the zone is subjected to a phase separation by raising its temperature and pressure to recover a liquid solvent phase containing a small amount of oil which can be reused as a solvent and an oil-enriched phase that can be freed of solvent by controlled volatilization. The solid residue is preferably freed of solvent by reducing the pressure thereon in at least two stages with heating, the solvent vapors being removed separately and compressed for recycling and reuse.
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Citations
31 Claims
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1. In a continuous method for extracting oil from communited oil-containing vegetable matter in which said vegetable matter is passed through a closed extraction zone in contact with a liquid extraction solvent medium wherein said extraction solvent medium is a normally gaseous hydrocarbon under a pressure in said extraction zone sufficient to liquify the same and up to about 250 psi, the improvement of continuously introducing said vegetable matter into said extraction zone for extraction therein by the steps comprising:
- advancing said vegetable matter through an elongated tubular screw-feeding zone communicating at its discharge end with one end of said extraction zone, subjecting said vegetable matter while within said screw-feeding zone to compacting pressure to create a region of compacted vegetable matter, and introducing under pressure into the compacted matter region for admixture with the compacted matter passing therethrough an innocuous normally liquid sealing medium, which if different from said oil is capable of being separated from the extracted oil, in an amount up to about 10% by weight of said compacted matter, and sufficient when mixed with the compacted matter to form the same into a generally plastic mass capable of sustaining the pressure in said extraction zone, the magnitude of said compacting pressure in the absence of said sealing medium being insufficient either to express said oil directly from said vegetable matter or to densify said matter to a solid dam of a density sufficient to contain the pressure in said extraction zone.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. In a continuous method for extracting rice oil from rice bran in which said rice bran is passed through a closed extraction zone in contact with a liquid extraction solvent medium wherein said extraction medium is a normally gaseous hydrocarbon under a pressure in said zone sufficient to liquify the normally gaseous hydrocarbon, the improvement comprising continuously introducing said rice bran into said extraction zone for extraction thereby the steps of:
- advancing said rice bran through an elongated tubular screw-feeding zone communicating at its discharge end with one end of said extraction zone, subjecting said rice bran while within said screw-feeding zone to compacting pressure to create a region of compacted rice bran, and introducing under pressure into the compacted bran region for admixture with the compacted bran passing therethrough an innocuous normally liquid sealing medium, which if different from rice oil is capable of being separated from the extracted rice oil, in an amount up to about 10% by weight of said compacted rice bran and sufficient when mixed with said compacted bran to form the same into a generally plastic mass capable of sustaining the pressure in said extraction zone, the magnitude of said compacting pressure in the absence of said medium being insufficient either to express said rice oil directly from said rice bran or to densify said rice bran to a solid dam of a density sufficient to contain the pressure in said extraction chamber.
- View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
Specification