Continuous operation of lipase-catalyzed reactions in nonaqueous solvents: Influence of the production of hydrophilic compounds

✍ Scribed by Alain Marty; Valérie Dossat; Jean-Stéphane Condoret

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 87 KB
• Volume: 56
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(19971020)56:2<232::aid-bit12>3.0.co;2-i

✦ Synopsis

In the field of biocatalysis in nonaqueous media, water has been identified as a crucial parameter which has to be carefully controlled. This article studies the continuous operation of a water-producing enzymatic reaction, here the esterification of oleic acid by ethanol in n-hexane catalyzed by Lipozyme TM . The conversion decreased significantly over time, eventually coming to a lower steady-state level. This would be due to the accumulation of the produced water into the enzyme fixedbed reactor, n-hexane being unable to evacuate this water out of the reaction vessel, because of the low polarity of this solvent. Therefore the conversion decreased until the produced water could be eliminated by the solvent achieving a steady state with a lower conversion. In supercritical carbon dioxide, a more hydrophilic solvent, steady state is at once obtained. This approach has been extended to reaction producing a hydrophilic compound, here glycerol during the transesterification between triolein and ethanol, and similar conclusions can be made.