This paper first describes an empirical model to characterize the deactivation of a catalyst used in the production of a specialty chemical based on actual plant data. This model is then used in a novel multiperiod MINLP optimization formulation that incorporates the empirical model in order to determine the optimal catalyst replacement policy and meet time varying product demand.

Thc natural flavin of lactate oxidase, FMN, was removed and replaced by the synthetic flavin 2-thioriboflavin 5’phosphate (Zthio FMN). Despite the differences in properties of the flavins, including an oxidation-reduction potential some 80 mV more positive than that of normal flavin the 2-thio-FMN enzyme behaves in practically all respects like the native enzyme. It catalyzes the oxidative deca...

Introduction Immobilization (heterogenization) of catalysts aims to obtain catalysts which combine the advantages of homogeneous catalysts (high activity, selectivity) and heterogeneous ones (stability, ease of separation from the reaction medium and the possibility of re-use in subsequent reaction cycles). One of the most promising directions of research in this field is the use of polymers as...

THE oxidation in animal tissues of metabolites such as lactate, malate, :hydroxybutyrate, triosephosphate etc., can be resolved into at least three consecutive reactions: (1) Metabolite +coenzyme I-* oxidized metabolite +reduced coenzyme I. (2) Reduced coenzyme I+ carrier -coenzyme I+ reduced carrier. (3) Reduced carrier +02-+ carrier. The first reaction is catalysed by a family of enzymes, eac...

We employed the overexpressed catalytic domains of wild-type Syrian hamster 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase, EC 1.1.1.34) and of mutant enzymes E558Q, H865Q, and D766N to investigate the roles of Glu558, His865, and Asp786 in catalysis. Five reactions were studied: reductive deacylation of HMG-CoA or of mevaldyl-CoA to mevalonate, reduction of mevaldehyde to m...

The key to obtaining an optimum performance of an enzyme is often a question of devising an effective method for its immobilization. In the present review, we describe a novel, versatile and effective methodology for enzyme immobilization as CLEAs (cross-linked enzyme aggregates). The method is exquisitely simple (involving precipitation of the enzyme from aqueous buffer followed by cross-linki...

Enzyme immobilization is necessary process to improve the bioactivity and stability of biocatalyst. In this study, glucose oxidase (GOx) enzyme was immobilized on plasma-treated fibrous carbon felt as a textile carrier produce heterogeneous catalyst. Genipin, naturally occurring crosslinker, that has less cytotoxicity than conventional crosslinkers, used in process. UV-Vis FTIR spectra confirme...