US EPA

4940629 

Journal Article 

Exploiting the pressure effect on lipase-catalyzed wax ester synthesis in dense carbon dioxide 

Knez, Z; Laudani, CG; Habulin, M; Reverchon, E 

2007 

Yes 

Biotechnology and Bioengineering
ISSN: 0006-3592
EISSN: 1097-0290 

John Wiley & Sons, Inc., 111 River Street Hoboken NJ 07030 USA, [mailto:custserv@wiley.com], [URL:http://www.wiley.com/] 

97 

6 

1366-1375 

English 

17221889 

10.1002/bit.21331 

The present work focuses on the thermodynamic interpretation of the lauryl oleate biosynthesis in high-pressure carbon dioxide. Lipase-catalyzed lauryl oleate production by oleic acid esterification with 1-dodecanol over immobilized lipase from Rhizomucor miehei (Lipozyme RM IM) was successfully performed in a sapphire window batch stirred tank reactor (BSTR) using dense CO(2) as reaction medium. The experiments were planned to elucidate the pressure effect on the reaction performance. With increasing the pressure up to 10 MPa, the catalytic efficiency of the studied enzyme improved rising up to a maximum and decreased at higher pressure values. Kinetic observations, exhibiting that dense CO(2) expanded reaction mixture in subcritical conditions led to higher performance than when diluted in a single supercritical phase, were elucidated by phase-equilibrium arguments. The experimental results were justified with emphasis on thermodynamic interpretation of the studied system. Particularly, the different reaction performances obtained were related to the position of the operating point with respect to the location of liquid-vapor phase boundaries of the reactant fatty acid/alcohol/CO(2) ternary system. The outlook for exploitation of CO(2) expanded phase at lower pressure compared to supercritical phase, with heterogeneous system in which the solid catalyst particles are exposed to dense CO(2) expanded reaction mixture, in developing new biotransformation schemes is promising. 

Rhizomucor miehei; Carbon dioxide; Pressure; Thermodynamics; Fatty acids; Esters; biotransformation; alcohols; Kinetics; Enzymes; Triacylglycerol lipase; Catalysts; Oleic acid; Esterification