| 학회 | 한국공업화학회 |
| 학술대회 | 2009년 봄 (04/15 ~ 04/17, 호텔인터불고(대구)) |
| 권호 | 13권 1호 |
| 발표분야 | 초청강연 |
| 제목 | Optimization of Semi-batch Chemical and Biochemical Reactors |
| 초록 | Optimization of a single chemical reactions through the manipulation of feed rate of reactant and withdrawal rate of reactor content reveals that the withdrawal rate takes place only at the end of reaction, not during the reaction, while the feed rate is optimally regulated to yield the optimal reactor configuration that includes a batch reactor (BR), a continuous flow reactor (CSTR), a plug flow reactor (PF) which is a spatial dual of BR, and a semi-batch reactor.The semi-batch mode of operation is known as a singular control. The optimum feed rate profile is concatenation of maximum, minimum and intermediate feed rates. The necessary condition for a single reaction to admit singular feed rate (semi-batch) is that the rate expression must be non-monotonic, i.e. it goes through a maximum with respect to reactant concentration. Thus, such single reaction as auto-catalytic, adiabatic exothermic, catalytic and reactant inhibited reactions are candidate for semi-batch operations. For multiple reactions such as series-parallel reactions, Denbigh reaction, Van de Vusse reaction, reactions with multiple catalysts can be optimally operated in semi-batch manner. Basically for series-parallel reactions, as long as the side reaction rate is more sensitive to the reactant concentration than the main reaction, the semi-batch operation may be superior. Biochemical reactions involve inductions, repressions, inhibitions and feedback regulation so that the overall rate appears to go through maximum with respect to the limiting substrate, i.e. the specific rates are non-monotonic. Thus, many industrially important products by made by cells (microbial, plant and animal) are manufactured using a semi-batch mode of reactor and the operation is known as fed-batch operation.Some examples are antibiotics, enzymes, amino acids polysaccharides, yeast and R-DNA products. When the yield coefficients are constant and the final time is free, the optimal policy maximizes the specific growth rate by maintaining the substrate concentration constant. For variable yield the singular feed rate maximizes the yield by maintaining the substrate concentration constant when the final time is free and when the final time is fixed, the singular feed rate maximize a weighted sum of the specific growth rate and the cell mass yield by varying the substrate concentration. When the yield coefficient is variable, the fed-batch operation mimics an unsteady state CSTR followed by a BR. |
| 저자 | Henry C. Lim |
| 소속 | Department of Chemical Engineering and Materials science |
| 키워드 | Semi-batch; Fed-batch; Reactions; Reactors |
