Phase equilibrium data pertaining to the extraction of cottonseed oil with ethanol and 2‐propanol

Abstract

SummaryBasic phase relation data have been obtained relative to the extraction of cottonseed oil with ethanol and 2‐propanol, especially as affected by water in the solvent. Mutual solubility diagrams have been constructed for cottonseed oil with ethanol and 2‐propanol of various aqueous concentrations. Tie‐line data at 30° C. have been obtained for the ternary ethanol‐cotton‐seed oil‐water and 2‐propanol‐cottonseed oil‐water systems. These combined data will be of assistance in the selection of the most desirable temperatures and moisture concentrations in the solvent extraction of cottonseed with these alcohols. Comparison with results previously published for soybean oil suggests that the mutual solubility data for cottonseed oil and aqueous ethanols are applicable to other vegetable oils over a wide range of iodine values.In general, the results indicate that 2‐propanol is the more desirable solvent since complete miscibility with the oil can be attained at temperatures below its normal boiling point even at moisture contents as high as 10% by weight whereas ethanol can tolerate only about 1.5% of water. High moisture contents result in more effective separation of the oil from the solvent when the miscella is cooled after extraction. Constant boiling aqueous ethanol and 2‐propanol present the disadvantage of requiring greater than atmospheric pressure during extraction in order to attain complete miscibility with the oil.

Comparison of alternative solvents for oils extraction

“…Solubility of oil in ethanol is dependent upon temperature and water content ( Fig. 1) (49)(50)(51)(52)(53). At temperatures higher than 70 C, soybean oil is miscible in all propor-…”

“…increases as water content of the mixture increases. In laboratory experiments, anhydrous ethanol extracted 1.9 times as much lipid materials from soybean flakes, and one-half as much nonlipid materials, as 90% ethanol (50).…”

“…Solubilities of a variety of oils in aqueous alcohol solutions have been determined at various temperatures (50)(51)(52)(53). The solubility of each oil in aqueous alcohol increases with temperature until the critical solution temperature is reached.…”

Performance of Nanofiltration Membranes for Solvent Purification in the Oil Industry

“…This solvent can be emitted during extraction and recovery and it has been identified as an air pollutant since it can react with other pollutants to produce ozone and photochemical oxidants [10,11]. Edible oil producers are more interested in alternative solvents less dependent on petroleum sources [12], such as ethanol [13,14], iso-propanol [15][16][17] and acetone [18].…”

Unfounded Solvent Recovery Process by Membrane Filtration

“…I also disagree with the statement that: ''Edible oil producers are more interested in alternative solvents less dependent on petroleum sources such as ethanol, isopropanol and acetone''. After all, the references quoted by the authors that refer to ethanol [11,12] date from 1955 to 1958; those referring to isopropanol [13] and [14] date from 1953 to 1957 respectively. Moreover, the article lists the first author in [15] as Kanth Rao, R instead of Rao, KR.…”