Won Keehoon, Jeong Jae Cheol, Lee Sun Bok
Department of Chemical Engineering, Division of Molecular and Life Sciences, and Institute of Environmental and Energy Technology, Pohang University of Science and Technology, San 31, Hyoja-Dong, Korea.
Biotechnol Bioeng. 2002 Sep 30;79(7):795-803. doi: 10.1002/bit.10339.
Real-time conversion estimation through macroscopic balancing was investigated for enzymatic esterification reactions in a solvent-free system. In principle, the conversion of ester synthesis can be determined from the amount of water produced by the reaction because water is formed as a by-product in the same molar ratio as the product. In this study, we show that the water production rate, and thereby the reaction conversion, can be estimated on-line from measurements of the relative humidity of the inlet and outlet air and the material balances of water in the system. In order to test the performance of the real-time conversion estimation method, the lipase-catalyzed esterification reaction of n-capric acid and n-decyl alcohol in solvent-free media was conducted while controlling the water activity at various values. When the reaction conversions estimated on-line were compared with those analyzed off-line by gas chromatography, good agreement was obtained: the average mean absolute error was +/- 2.4% of the reaction conversion despite the simplicity of the method. The on-line estimation method presented here requires no expensive or complicated analytical instruments and no sampling of reaction medium. It can be used for monitoring nonaqueous enzymatic reactions where water is produced or consumed during reaction.
针对无溶剂体系中的酶促酯化反应，研究了通过宏观平衡进行实时转化率估算的方法。原则上，酯合成反应的转化率可根据反应生成水的量来确定，因为水作为副产物生成，其摩尔比与产物相同。在本研究中，我们表明，通过测量进出气的相对湿度以及系统中水的物料平衡，可以在线估算水的生成速率，进而估算反应转化率。为了测试实时转化率估算方法的性能，在无溶剂介质中进行了正癸酸与正癸醇的脂肪酶催化酯化反应，并将水活度控制在不同值。将在线估算的反应转化率与通过气相色谱离线分析得到的转化率进行比较时，结果吻合良好：尽管该方法简单，但平均平均绝对误差为反应转化率的±2.4%。本文提出的在线估算方法不需要昂贵或复杂的分析仪器，也无需对反应介质进行采样。它可用于监测在反应过程中有水生成或消耗的非水酶促反应。
