Capillary Reactor Research Articles

Modeling of hollow‐fiber capillary reactor for the production of L‐Alanine with coenzyme regeneration

Continuous production of L-alanine with conjugated enzyme systems of alanine dehydrogenase (AlaDH) and lactate dehydrogenase (LDH) or alcohol dehydrogenase (ADH) was carried out with NAD regeneration in an ultrafiltration hollow-fiber capillary reactor (HFCR) which was proposed as a test bioreactor with very small scale. In the AlaDH/LDH system, pyruvate is the intermediate product for L-alanine so that an optimal point existed in pyruvate concentration for the production rate of L-alanine. NAD cycling number of 4850 and L-alanine productivity of 61.7 mmol/L h were obtained at the best condition. In the AlaDH/ADH system, however, the substrate inhibition in the AlaDH reaction by pyruvate should be considered and the best results of NAD cycling number and (L)-alanine productivity were 2700 and 13.5 mmol/L h, respectively. In consideration of concentration distribution and mixing in the axial direction on an HFCR, performance of the reactor was theoretically analyzed with a multistage stirred tank reactor model combined with the kinetic model based on all the elementary reactions involved. Although quantitative discrepancy existed in some cases, the present theoretical model could explain experimental results and is expected to be generally applicable to standard hollow fiber reactors.

Effects of temperature on the hydrolysis of lactose by immobilized β‐galactosidase in a capillary bed reactor

The effects of temperature on the hydrolysis of lactose by immobilized beta-galactosidase were studied in a continuous flow capillary bed reactor. Temperature affects the rates of enzymatic reactions in two ways. Higher temperatures increase the rate of the hydrolysis reaction, but also increase the rate of thermal deactivation of the enzyme. The effect of temperature on the kinetic parameters was studied by performing lactose hydrolysis experiments at 15, 20, 25, 30, and 40 degrees C. The kinetic parameters were observed to follow an Arrhenius-type temperature dependence. Galactose mutarotation has a significant impact on the overall rate of lactose hydrolysis. The temperature dependence of the mutarotation of galactose was effectively modelled by first-order reversible kinetics. The thermal deactivation characteristics of the immobilized enzyme reactor were investigated by performing lactose hydrolysis experiments at 52, 56, 60, and 64 degrees C. The thermal deactivation was modelled effectively as a first order decay process. Based on the estimated thermal deactivation rate constants, at an operating temperature of 40 degrees C, 10% of the enzyme activity would be lost in one year.

Lactose hydrolysis by immobilized β‐galactosidase in capillary bed reactor

The hydrolysis of lactose by immobilized beta-galactosidase was studied in a continuous-flow capillary bed reactor operating at 30 degrees C. Solutions containing 50, 100, and 150 g lactose and 0.5 g sodium acetate/L were fed to the reactor. Lactose conversions ranging from 24% to greater than 99% were achieved at reactor space times ranging from 0.06 to 6.3 min. These conversion data were successfully modeled in terms of a plug flow reactor model and a form of Michaelis-Menten kinetics which included competitive inhibition by both the alpha and beta forms of galactose.

On‐line hydrogenation in GC‐MS analysis of cyclic fatty acid monomers isolated from heated linseed oil

AbstractA simple on‐line hydrogenation method in GC‐MS analysis of unsaturated fatty acid esters is described. Using hydrogen as carrier gas, hydrogenation takes place in a capillary reactor connected to the outlet of the analytical column in the oven of the gas chromatograph. The reactor is a fused silica tube (60 cm×0.32 mm i.d.) coated with palladium acetylacetonate. Selective hydrogenation of olefinic bonds is achieved after a normal chromatographic run. Structural information (carbon‐skeleton, double bond equivalents) can thus be deduced, and structural correlations between the saturated and unsaturated components can be obtained. Structures of cyclic fatty acid esters isolated from heated linseed oil were elucidated using this simple method which was found very useful for structural investigations on unsaturated compounds by GC‐MS.

Post-capillary fluorescence detection in capillary zone electrophoresis using o-phthaldialdehyde

A post-capillary fluorescence detection scheme for capillary zone electrophoresis is described using o-phthaldialdehyde (OPA) as the tagging reagent. Use of a coaxial capillary reactor affords mixing of the OPA reagent with migrating zones without excessive zone broadening. The detector is linear over three orders of magnitude and shows detection limits for amino acids and proteins in the femtogram (attomol) range.

Capillary membrane reactors: Performance and applications

Purpose of the work is the characterization of capillary membranes with entrapped cells, from a mechanical and a kinetic point of view. Polysulphone capillary membranes have been prepared by the phase inversion technique, extruding in a specially designed apparatus the polymer solution containing lyophilized cells of thermophilic Sulfolobus solfataricus. The mechanical properties of such capillary membranes were tested and compared to those of cell-free fibres in terms of bubble formation point and outburst under pressure, and of their behaviour under a stress—strain analysis. Fibres permeability to water and to the acetate buffer (pH 5) used in kinetic experiments was determined in the range of temperatures from 25°C to 70°C. Regarding the entrapped cells kinetic behaviour, an enzyme in particular was selected in bacterial enzymatic heritage, i.e. β-galactosidase, for the conversion of lactose to glucose and galactose. Kinetic assays were performed on bundles of fibres assembled in tube and shell reactors at different substrate concentrations and transmembrane pressures.

Malic enzyme immobilization in continuous capillary membrane reactors

The oxydative decarboxylation of L-malic acid is a fundamental step in malolactic fermentation, which in turn is a process of great importance in the food and wine industry for the production of fruit juices and wines of fair organoleptic properties. Experiments were carried out on L-malic acid decarboxylation catalyzed by malic enzyme (E.C.1.1.1.40) immobilized using three different techniques. A kinetic analysis was performed in order to define an enzyme reactor system suitable for development and practical applications. In this preliminary investigation, the stability of the immobilized enzyme compared with that of the native enzyme was investigated, as were the optimal operating conditions.

Characterization of an Enzymatic Capillary Membrane Reactor

Annals of the New York Academy of SciencesVolume 434, Issue 1 p. 123-126 Characterization of an Enzymatic Capillary Membrane Reactor G. IORIO, G. IORIO Department of Chemical Engineering University of Naples Piazzale Tecchio 80125 Naples, ItalySearch for more papers by this authorG. CATAPANO, G. CATAPANO Department of Chemical Engineering University of Naples Piazzale Tecchio 80125 Naples, ItalySearch for more papers by this authorE. DRIOLI, E. DRIOLI Department of Chemical Engineering University of Calabria Arcavacata di Rende (CS), ItalySearch for more papers by this authorM. ROSSI, M. ROSSI Department of Enzymology School of Science University of Naples Via Mezzocannone 16 80100 Naples, ItalySearch for more papers by this authorR. RELLA, R. RELLA International Institute of Genetics and Biophysics CNR Viale Marconi 10 80125 Naples, ItalySearch for more papers by this author G. IORIO, G. IORIO Department of Chemical Engineering University of Naples Piazzale Tecchio 80125 Naples, ItalySearch for more papers by this authorG. CATAPANO, G. CATAPANO Department of Chemical Engineering University of Naples Piazzale Tecchio 80125 Naples, ItalySearch for more papers by this authorE. DRIOLI, E. DRIOLI Department of Chemical Engineering University of Calabria Arcavacata di Rende (CS), ItalySearch for more papers by this authorM. ROSSI, M. ROSSI Department of Enzymology School of Science University of Naples Via Mezzocannone 16 80100 Naples, ItalySearch for more papers by this authorR. RELLA, R. RELLA International Institute of Genetics and Biophysics CNR Viale Marconi 10 80125 Naples, ItalySearch for more papers by this author First published: December 1984 https://doi.org/10.1111/j.1749-6632.1984.tb29812.xCitations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume434, Issue1Enzyme Engineering 7December 1984Pages 123-126 RelatedInformation

On-line hydrogenation of unsaturated and saturated sample components in capillary reactors coupled to either inlet or outlet of capillary columns

A special coupling piece for the connection of fused silica or softglass capillary hydrogenation reactors with capillary separation columns using a double oven GC instrument is described. The temperatures of reactor and column can be independently adjusted thereby. This system for on-line hydrogenation also includes two injectors to be used either before the reactor or before the column and a device for trapping the hydrogenated material inside the column. Platinum and palladium catalysts of various activities were investigated, aromatic hydrocarbons and compounds containing polar functional groups can be hydrogenated easily.

On-line hydrogenation of unsaturated and saturated sample components in capillary reactors coupled to either inlet or outlet of capillary columns

On-line hydrogenation of unsaturated and saturated sample components in capillary reactors coupled to either inlet or outlet of capillary columns

Excited state bromine atom and molecule reactions

Excitation of bromine at wavelengths near the dissociation limit of the B 3Π+0u electronic state is shown to produce substitution and extraction reactions of excited bromine with olefins. These reactions are produced by drastically shortening free-radical chains in contrast to more conventional photochemical experiments which yield addition products only. Shortening of radical chains is accomplished by irradiating a flowing gas mixture in a capillary optical reactor. Wavelength selective photochemical reactions of excited 2P1/2 bromine atoms are found to occur simultaneously with gas phase ground state 2P3/2 atom reactions and with surface reactions. Evidence for reactions of electronically excited molecules of bromine in the B 3Π+0u state is also found.

Special techniques in the combination of gas chromatography and mass spectrometry

On the basis of a new open split-type connection of a gas chromatograph and a mass spectrometer, particularly suitable for glass capillary columns, procedures are described for decreasing a peak concentration that is too high by dilution and increasing a maximum peak concentration that is too low by trapping and subsequent evaporation. On-line hydrogenation in a glass capillary reactor with palladium as catalyst and its analytical application is described. A low-cost quadrupole mass spectrometer as an independent detector has been mounted inside a mass spectrometer. The resulting possibilities and advantages are discussed.