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United States Department of Agriculture

Agricultural Research Service

Title: Isohexane As a Solvent for Extraction

Author
item Wan, Peter

Submitted to: Inform
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 1996
Publication Date: N/A

Interpretive Summary: Based on bench scale extraction results, both heptane and isohexane were recommended as potential alternate hydrocarbon solvents to replace hexane which was considered an air toxicant. A cottonseed crushing plant with a capacity of 300 tons/day decided to test both solvents supplied by Phillips Petroleum Company. Plant trials results showed that both solvents can produce oil and meal with acceptable quality. But due to the high energy demand to desolventize heptane extracted meal, the test with heptane was stopped after the third day of testing. Isohexane has a lower boiling range than hexane and permitted more than a 20% higher throughput and as much as a 40% savings in natural gas consumption at one plant. This observation has been confirmed by the same plant with an additional extended test with isohexane. A second plant operating at 50% of designed capacity tested isohexane without any retrofitting and operational difficulties. But this plant did not observe any appreciable amount of energy savings. From these plant trials, it appears that isohexane can be used to replace hexane in an existing extraction facility with minimum or no retrofit. Those plants already operating at full capacity, could also experience significant throughput rate increases and energy savings by using isohexane.

Technical Abstract: Laboratory extraction results found several hydrocarbon solvents extract nearly as well as commercial hexane. Both heptane and isohexane were recommended as potential alternate hydrocarbon solvents to replace hexane due to their cost and availability. A cottonseed crushing plant with a capacity of 300 tons/day decided to test both solvents supplied by Phillips Petroleum Company. Plant trials results showed that both solvents can produce oil and meal with acceptable quality. But the high energy demand to desolventize heptane from oil and meal forced the plant to stop the test after the third day. Isohexane has a lower boiling range than hexane and permitted more than a 20% higher throughput and as much as a 40% savings in natural gas consumption. This observation has been confirmed by the same plant with an additional extended test using isohexane. A second plant operating at 50% of designed capacity tested isohexane without any retrofiting and operational difficulties. But this plant did not observe appreciable amount of energy savings. From these plant trials, it appears that isohexane can be used to replace hexane in an existing extraction facility with minimum or no retrofit. Those plants already operating at full capacity, could also experience significant throughput rate increases and energy savings by using isohexane.

Last Modified: 9/23/2014
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