Studies on a continuous recycle reactor for a lipase-catalysed processing of ricebran oil
TL;DR: In this paper, the authors developed a continuous recycle reactor which efficiently performs emulsion type enzymatic reactions, where the reactor column is filled with immobilised lipase and the reactions are effected by pumping the pre-prepared oil-water emulsion through the bottom of the reactor.
Abstract: The authors have developed a continuous recycle reactor which efficiently performs emulsion type enzymatic reactions. The reactor column is filled with immobilised lipase and the reactions are effected by pumping the pre-prepared oil-water emulsion through the bottom of the reactor. A part of the product was recycled back and this type of recycling greatly improves the productivity of fatty acid compared to continuous once-through reactor without recycling. The recycle reactor could be continuously run for 35 days without decrease in conversions. The performance of the reactor was interpreted by a model and the theoretical conversion was compared with the experimental data.
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TL;DR: Theoretical equations were developed based on pseudo-steady state approximation and Michaelis-Menten rate expression to predict the time course of conversion due to enzyme deactivation and apparent half-life of the immobilized enzyme activity in PFR and CSTR under constant feed rate policy for no diffusion limitation and diffusion limitation of first order.
Abstract: Experiments on deactivation kinetics of immobilized lipase enzyme fromCandida cylindracea were performed in stirred batch reactor using rice bran oil as the substrate and temperature as the deactivation parameter. The data were fitted in first order deactivation model. The effect of temperature on deactivation rate was represented by Arrhenius equation. Theoretical equations were developed based on pseudo-steady state approximation and Michaelis-Menten rate expression to predict the time course of conversion due to enzyme deactivation and apparent half-life of the immobilized enzyme activity in PFR and CSTR under constant feed rate policy for no diffusion limitation and diffusion limitation of first order. Stability of enzyme in these continuous reactors was predicted and factors affecting the stability were analyzed.
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Book•
30 Jun 1972TL;DR: An overview of Chemical Reaction Engineering is presented, followed by an introduction to Reactor Design, and a discussion of the Dispersion Model.
Abstract: Partial table of contents: Overview of Chemical Reaction Engineering. HOMOGENEOUS REACTIONS IN IDEAL REACTORS. Introduction to Reactor Design. Design for Single Reactions. Design for Parallel Reactions. Potpourri of Multiple Reactions. NON IDEAL FLOW. Compartment Models. The Dispersion Model. The Tank--in--Series Model. REACTIONS CATALYZED BY SOLIDS. Solid Catalyzed Reactions. The Packed Bed Catalytic Reactor. Deactivating Catalysts. HETEROGENEOUS REACTIONS. Fluid--Fluid Reactions: Kinetics. Fluid--Particle Reactions: Design. BIOCHEMICAL REACTIONS. Enzyme Fermentation. Substrate Limiting Microbial Fermentation. Product Limiting Microbial Fermentation. Appendix. Index.
8,257 citations
"Studies on a continuous recycle rea..." refers methods in this paper
...verified by differentiating the following expressions and equating it to zero [ 9 ]:...
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...Modelling of the continuous recycle reactor Based on the performance of the reactor the proposed Levenspiel model is [ 9 ] 0.74 %...
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TL;DR: A simple and rapid colorimetric method was developed to determine the lipase activity for fat splitting by observing the color developed using cupric acetate-pyridine as a color developing reagent.
Abstract: A simple and rapid colorimetric method was developed to determine the lipase activity for fat splitting Free fatty acids produced by lipase from triacylglycerols were determined by observing the color developed using cupric acetate-pyridine as a color developing reagent This modified method requires only a few minutes to determine the free fatty acids, whereas it takes over 20 min by the conventional methods which require solvent evaporation and centrifugation steps The sensitivity and reproducibility of the method were good for caproic, caprylic, capric, lauric, myristic, palmitic, stearic and oleic acids
351 citations
01 Mar 1983
TL;DR: Lipase from Candida cylindracea was immobilized by entrapment with photo-crosslinkable resin prepolymers or urethane prepolymer, and by covalent binding or by adsorption to different types of porous inorganic or organic supports to show some activity for hydrolysis of olive oil.
Abstract: Lipase from Candida cylindracea was immobilized by entrapment with photo-crosslinkable resin prepolymers or urethane prepolymers, and by covalent binding or by adsorption to different types of porous inorganic or organic supports. All of the immobilized lipase preparations thus obtained showed some activity for hydrolysis of olive oil. Lipase entrapped with a hydrophobic photo-cross-linkable resin prepolymer exhibited the highest activity, which was about 30% of that of the free counterpart. Entrapment method enabled lipase to gain operational stability. Semicontinuous hydrolysis of olive oil using immobilized lipase was also accomplished in a packed-bed reactor with a recycling system. In this reactor, immobilized lipase was observed to have the sufficient activity and stability.
140 citations
TL;DR: In this article, a packed bed reactor containing 1 g of mycelia fed at 1 mL/min with a solution of 2.5% (w/v) olive oil in di-isopropyl ether gave a fatty acid yield of 45% at 30°C.
Abstract: Continuous hydrolysis of triglyceride in organic solvent systems using Rhizopus arrhizus mycelia as a source of insolubilized lipase has been studied in packed-bed and stirred-tank reactors. Typically a packed bed reactor containing 1 g of mycelia fed at 1 mL/min with a solution of 2.5% (w/v) olive oil in di-isopropyl ether gave a fatty acid yield of 45% at 30°C. The optimum water concentration was found to be 0.17% (w/v) except under conditions of high oil feed concentration and high yield where no optimum was established. No temperature optimum was observed over the range 20–55°C. Calculated activation energies of 13–20 kJ/mol, depending on temperature, were lower, while Km(app) values of 0.1–0.3M were higher than those for hydrolysis in conventional aqueous emulsion systems. No evidence of any significant diffusional limitation, which could account for these values, was obtained. The mycelia showed a loss of activity of 0.6–1.0%h at 30°C. The packed bed proved markedly superior to the stirred tank for this system.
70 citations
"Studies on a continuous recycle rea..." refers methods in this paper
...Liberman and Ollis [2] and also George Bell et al. [ 3 ] have studied the production of fatty acids in a continuous reactor using tributyrin and olive oil respectively....
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TL;DR: The Michaelis constant of the stainless steel–lipase was found to be equal to that of the free enzyme, suggesting that adsorption and subsequent crosslinking does not alter the enzyme–substrate affinity.
Abstract: Pancreatic lipase has been immobilized onto stainless steel beads by adsorption followed by crosslinking, and onto polyacrylamide by covalent bonding. The activities of the two types of immobilized enzyme toward the particulate substrate, tributyrin emulsion droplets, were determined experimentally, and rate constants based on Michaelis-Menten kinetics were calculated. The activity of the stainless steel-lipase was determined for various flow conditions and for various support sizes by the use of a differential fluidized bed recycle reactor. The rate constants calculated indicate that the experimental reaction rate is free from mass transfer influences, since the observed Michaelis constant does not vary with the fluidization velocity or with the support particle size. In addition, the Michaelis constant of the stainless steel-lipase was found to be equal to that of the free enzyme, suggesting that adsorption and subsequent crosslinking does not alter the enzyme-substrate affinity. The emulsion substrate mass transfer rates, calculated from the filtration theory, indicate that each substrate particle which contact the immobilized enzyme is hydrolyzed to a significant extent. The experimentally determined kinetic rate constants may be used directly to predict the size of integral fluidized bed reactors.
63 citations