This report is an account of the pilot plant studies on cooking and thinning of corn starch with ... more This report is an account of the pilot plant studies on cooking and thinning of corn starch with free α-amylase and the conversion of the resulting dextrin to glucose with glucoamylase immobilized to porous silica. Previous pilot plant work, in which dextrin produced by acid hydrolysis was further hydrolyzed to glucose with immobilized glucoamylase, has been reported elsewhere (1). Mainly emphasized here is the effect of feed composition on the rate of intraparticle diffusion and the effect of enzyme immobilization on the reactor selectivity.
ABSTRACT Glucoamylase was covalently attached to porous silica particles and investigated for its... more ABSTRACT Glucoamylase was covalently attached to porous silica particles and investigated for its applicability as an industrial catalyst in the production of glucose from starch hydrolysates. Reactivity at various reaction conditions, as well as enzyme loading, reaction kinetics, diffusional effects, and thermal stability, were determined in laboratory scale experiments. Pilot scale tests on continuous production of glucose were performed in a 1 cubic foot packed column reactor that could produce approximately 1,000 lbs/d glucose at 40°C. The maximum glucose concentration (based on dissolved solids) varied from 87 to 93% depending on the dextrose equivalent (D.E.) and degree of retrogradation of the feed dextrin. In 80 days of continuous operation no appreciable enzyme deactivation was observed. Initial sterilization of the reactor and continuous heat sterilization of the feed stream (120°C, 3–4 min) virtually ensured operation of the immobilized enzyme reactor at low levels of contamination, typical bacteria counts of the product effluent being 30–50/ml. Occasional interruption of the system resulted in much higher levels of microorganisms but did not affect the overall enzyme reactivity.
A computational model is developed to calculate thermodynamic phase equilibria in aqueous solutio... more A computational model is developed to calculate thermodynamic phase equilibria in aqueous solutions of fluoride, phosphate, and hydroxide up to 100° C. A variety of data are used, including isopiestic and electromotive force measurements, freezing point data, ...
Mesure des coefficients de distribution et calcul des facteurs de separation pour l'ethanol e... more Mesure des coefficients de distribution et calcul des facteurs de separation pour l'ethanol et l'eau de solutions aqueuses vers divers solvants organiques
Density increases in caustic-side solvent extraction (CSSX) solvent have been observed in separat... more Density increases in caustic-side solvent extraction (CSSX) solvent have been observed in separate experimental programs performed by different groups of researchers. Such changes indicate a change in chemical composition. Increased density adversely ...
The rate of biological processes in aerobic fermentation and waste water treatment is often limit... more The rate of biological processes in aerobic fermentation and waste water treatment is often limited by the rate of dissolution of oxygen from air bubbles into the liquid. A clear understanding of interfacial resistance to oxygen transfer is thus of importance. An oxygen sensing microprobe was used to detect a stagnant film and a penetrable zone near an air-water interface contaminated with surfactants. The technique, when used in clean water, can also measure the frequency of surface renewal. A linear relationship was found between the square root of the renewal rate sO.5 and the interfacial mass transfer coefficient kL, which is predicted by the Danckwerts theory.
This report is an account of the pilot plant studies on cooking and thinning of corn starch with ... more This report is an account of the pilot plant studies on cooking and thinning of corn starch with free α-amylase and the conversion of the resulting dextrin to glucose with glucoamylase immobilized to porous silica. Previous pilot plant work, in which dextrin produced by acid hydrolysis was further hydrolyzed to glucose with immobilized glucoamylase, has been reported elsewhere (1). Mainly emphasized here is the effect of feed composition on the rate of intraparticle diffusion and the effect of enzyme immobilization on the reactor selectivity.
ABSTRACT Glucoamylase was covalently attached to porous silica particles and investigated for its... more ABSTRACT Glucoamylase was covalently attached to porous silica particles and investigated for its applicability as an industrial catalyst in the production of glucose from starch hydrolysates. Reactivity at various reaction conditions, as well as enzyme loading, reaction kinetics, diffusional effects, and thermal stability, were determined in laboratory scale experiments. Pilot scale tests on continuous production of glucose were performed in a 1 cubic foot packed column reactor that could produce approximately 1,000 lbs/d glucose at 40°C. The maximum glucose concentration (based on dissolved solids) varied from 87 to 93% depending on the dextrose equivalent (D.E.) and degree of retrogradation of the feed dextrin. In 80 days of continuous operation no appreciable enzyme deactivation was observed. Initial sterilization of the reactor and continuous heat sterilization of the feed stream (120°C, 3–4 min) virtually ensured operation of the immobilized enzyme reactor at low levels of contamination, typical bacteria counts of the product effluent being 30–50/ml. Occasional interruption of the system resulted in much higher levels of microorganisms but did not affect the overall enzyme reactivity.
A computational model is developed to calculate thermodynamic phase equilibria in aqueous solutio... more A computational model is developed to calculate thermodynamic phase equilibria in aqueous solutions of fluoride, phosphate, and hydroxide up to 100° C. A variety of data are used, including isopiestic and electromotive force measurements, freezing point data, ...
Mesure des coefficients de distribution et calcul des facteurs de separation pour l'ethanol e... more Mesure des coefficients de distribution et calcul des facteurs de separation pour l'ethanol et l'eau de solutions aqueuses vers divers solvants organiques
Density increases in caustic-side solvent extraction (CSSX) solvent have been observed in separat... more Density increases in caustic-side solvent extraction (CSSX) solvent have been observed in separate experimental programs performed by different groups of researchers. Such changes indicate a change in chemical composition. Increased density adversely ...
The rate of biological processes in aerobic fermentation and waste water treatment is often limit... more The rate of biological processes in aerobic fermentation and waste water treatment is often limited by the rate of dissolution of oxygen from air bubbles into the liquid. A clear understanding of interfacial resistance to oxygen transfer is thus of importance. An oxygen sensing microprobe was used to detect a stagnant film and a penetrable zone near an air-water interface contaminated with surfactants. The technique, when used in clean water, can also measure the frequency of surface renewal. A linear relationship was found between the square root of the renewal rate sO.5 and the interfacial mass transfer coefficient kL, which is predicted by the Danckwerts theory.
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