TY - JOUR
T1 - On-line conversion estimation for solvent-free enzymatic esterification systems with water activity control
AU - Won, Keehoon
AU - Lee, Sun Bok
PY - 2002
Y1 - 2002
N2 - On-line conversion estimation of enzymatic esterification reactions in solvent-free media was investigated. In principle, conversion to ester can be determined from the amount of water produced by the reaction, because water is formed as a by-product in a stoichiometric manner. In this study, we estimated the water production rate only from some measurements of relative humidity and water balances without using any analytical methods. In order to test the performance of the on-line conversion estimation, the lipase-catalyzed esterification of n-capric acid and K-decyl alcohol in solvent-free media was performed whilst controlling water activity at various values. The reaction conversions estimated on-line were similar to those determined by offline gas chromatographic analysis. However, when the water activity was controlled at higher values, discrepancies between the estimated conversion values and the measured values became significant. The deviation was found to be due to the inaccurate measurement of the water content in the reaction medium during the initial stages of the reaction. Using a digital filter, we were able to improve the accuracy of the on-line conversion estimation method considerably. Despite the simplicity of this method, the on-line estimated conversions were in good agreement with the off-line measured values.
AB - On-line conversion estimation of enzymatic esterification reactions in solvent-free media was investigated. In principle, conversion to ester can be determined from the amount of water produced by the reaction, because water is formed as a by-product in a stoichiometric manner. In this study, we estimated the water production rate only from some measurements of relative humidity and water balances without using any analytical methods. In order to test the performance of the on-line conversion estimation, the lipase-catalyzed esterification of n-capric acid and K-decyl alcohol in solvent-free media was performed whilst controlling water activity at various values. The reaction conversions estimated on-line were similar to those determined by offline gas chromatographic analysis. However, when the water activity was controlled at higher values, discrepancies between the estimated conversion values and the measured values became significant. The deviation was found to be due to the inaccurate measurement of the water content in the reaction medium during the initial stages of the reaction. Using a digital filter, we were able to improve the accuracy of the on-line conversion estimation method considerably. Despite the simplicity of this method, the on-line estimated conversions were in good agreement with the off-line measured values.
KW - Lipase-catalyzed esterification
KW - On-line conversion estimation
KW - Solvent-free media
KW - Water activity control
UR - http://www.scopus.com/inward/record.url?scp=0038541286&partnerID=8YFLogxK
U2 - 10.1007/BF02935883
DO - 10.1007/BF02935883
M3 - Article
AN - SCOPUS:0038541286
SN - 1226-8372
VL - 7
SP - 76
EP - 84
JO - Biotechnology and Bioprocess Engineering
JF - Biotechnology and Bioprocess Engineering
IS - 2
ER -