bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactors for ethanol production using immobilised yeast cells
Authors: Qureshi Nasibuddin , Pai J. S. , Tamhane D. V. 
Published: July 2010

AbstractEthanol production by immobilised yeast cells in packed‐bed column reactors was significantly affected by the hold‐up of CO2 produced during the fermentation. Compartmentalisation of the reactor minimises CO2 hold‐up and prevents flotation of immobilised cell beads during operation and bead rupture during shut‐down conditions. In a reactor of dimensions 2·2 × 60 cm, a rate of ethanol production of 5·11 g h−1 at a dilution rate of 1·27 h−1 was achieved, when 18% (w/v) glucose solution was fed at the bottom at pH 5·5 and temperature 33–35°C. In larger reactors of sizes 4 ×; 40 cm and 8 × 80 cm the rates of ethanol production and CO2 hold‐ups were 5·11 and 5·37 g h−1 and 48·66% and 40·66% and 40·79% of the void volume at dilution rates of 1·27 h−1 and 1·67 h1, respectively. The CO2 hold‐ups in column reactors (4 × 40 cm) held in inclined (43° from horizontal) or horizontal positions were 41·33% and 46·67% of the void volume, respectively. Double and triple series reactors (each of dimensions 2·2 × 60 cm) showed better performance than a single verticle reactor (2·2 × 60 cm).
Mass transfer of sodium chloride in simulated crystallizing pond during the rainfall period
Authors: Huang Ting‐Chia , Juang Ruey‐Shin , Huang Tzung‐Huei 
Published: July 2010

AbstractThe mass transfer equation describing the transport phenomena of sodium chloride is derived for the simulated crystallizing pond during the rainfall period. According to the theoretical and experimental results, the dissolution rate of NaCl is shown to be controlled by the combination of salt transport including the diffusion and convection of solute in solution and surface dissolution reaction including the desorption and surface diffusion of solute. It is found that both the dissolution and convective mass transfer coefficients are proportional to the total rainfall quantity, and inversely proportional to the brine depth. The variation of dissolution mass transfer coefficient to the total rainfall quantity and brine depth is correlated from the experimental results. Correlation of the convective mass transfer coefficient is also obtained by using the numerical solution of the mass transfer equation.
Hydrolysis of sugar cane bagasse with hydrochloric acid, promoted by ultrasound
Authors: Schuchardt Ulf , Joekes Inés , Duarte Humberto C. 
Published: July 2010

AbstractUltrasound effectively promotes the hydrolysis of pre‐hydrolysed sugar cane bagasse using 38% concentrated hydrochloric acid. In combination with lithium chloride, ultrasonic promotions as high as 62% were observed. Of the three frequencies (25, 35 and 40 kHz) studied, the lowest promoted the hydrolysis most effectively but, when in combination with lithium chloride, reoligomerised the sugars. The higher frequencies of 35 and 40 kHz required larger concentrations of lithium chloride for complete conversion. Irradiation with 40 kHz also promoted subsequent acid hydrolysis of the sugar oligomers.
Separation of ethanol‐water mixtures using 3A molecular sieve
Authors: Cartón Angel , González Gerardo , Torre Angeles Iñiguez De La , Cabezas Jose Luis 
Published: July 2010

AbstractAn experimental study of 3A molecular sieve behavior, in order to obtain anhydrous ethanol, was developed. The adsorption of water in vapor phase was performed in an essentially isothermal fixed bed. 99·9 wt% ethanol was recovered operating with azeotropic distillation and different flow rates. A simple model in terms of a driving force and linear equilibrium was tested. Runs in liquid phase were also carried out, obtaining lower treatment capacities than when working in vapor phase.
Kinetics of naphthalene sulphonation with 96 wt % sulphuric acid
Authors: Nowicki Lech , Zarzycki Roman 
Published: July 2010

AbstractAn empirical approach to the kinetic investigation of naphthalene sulphonation with 96% sulphuric acid is presented. The best parameter estimates for the proposed kinetic model were obtained by non‐linear regression of experimental data.
Automated production scale affinity purification of monoclonal antibodies
Authors: Kenney A. C. , Chase H. A. 
Published: July 2010

AbstractThis paper describes the use of automation to improve the efficiency of affinity chromatography as a production technique. The use of automation in development of affinity processes is described together with an analysis of the benefits of automating production systems. The paper considers what factors are important in achieving an efficient affinity process on a production scale. The discussion is supported with data illustrating the use of immobilised Protein A to purify large quantities of monoclonal antibody from cell culture. The paper concludes with a brief discussion of possible future developments and extensions of automation in affinity processes.
Urease immobilization on an alkylamine derivative of titanium (IV)‐porous silica: Kinetics and operational stability
Authors: Martins Maria Barbara F. , Cruz Maria Eugenia M. , Cabral Juaquim M. S. , Kennedy John F. 
Published: July 2010

AbstractFor the purpose of immobilizing urease (urea amidohydrolase, EC 3.5.1.5) for routine determination of urea, a covalent bond immobilization method on titanium (IV) chloride activated silica supports1,2 was used. Several parameters were studied in order to optimize the residual activity upon immobilization and during operation. The kinetic constants of the immobilized enzyme form (Km=92 mmol dm−3, Vmax=752 μmole min−1 mg−1) are much higher than those of the free preparation (Km=31 mmol dm−3, Vmax=128 μmole min−1 mg−1). The optimum pH of the immobilized enzyme preparation was shifted to higher values, from pH 7·4 to 8. The optimum temperatures for the immobilized and free forms were 75 and 65°C, respectively. The activation energy of the immobilized form is four times smaller than that of the free, indicating less sensitivity to temperature. It was also observed that the immobilized enzyme exhibits a higher heat stability than the free enzyme. From these studies the conditions for optimal operation and retention of stability of the immobilized enzyme were determined. The enzyme immobilized on the alkylamine derivative of porous silica can be reused at 37°C for several hours a day with 100% retention of its initial activity for at least 1200 h of total life (i. e. operating time at 37°C plus stationary time at 4°C).
Ion exchange characteristics of ceric tungstate: Kinetics of exchange
Authors: Mikhail Etidal M. , Misak Nasr Z. 
Published: July 2010

AbstractThe kinetics of exchange of Cs+, Ag+, Zn2+ and Sc3+ on ceric tungstate were studied under particle diffusion control conditions at different temperatures. At the studied temperatures, the mobility of the monovalent ions in the prepared exchanger is higher than that of the multivalent ones, presumably due to weaker electrostatic interaction with the exchange sites. The activation energy data point to a substantial or complete dehydration of the ions diffusing in the narrow pores of the exchanger. The highest activation energy is displayed by Cs+ having the largest crystallographic radius.
Optimization of sucrose phosphorylase production by Leuconostoc mesenteroides
Authors: Vandamme Erick J. , Loo Jan Van , Simkens Eric , Laporte Andre De 
Published: July 2010

AbstractEnvironmental optimization of the Leuconostoc mesenteroides ATCC 12291 sucrose phosphorylase fermentation process was undertaken. The effects of pH control, fermentation temperature and medium composition on growth, culture viscosity, sucrose utilization pattern and dynamics of enzyme fermentation were studied. Optimized fermentations were run at controlled pH 7 at 32°C yielding high enzyme levels. Applications of sucrose phosphorylase are discussed.
Development of a microcomputer‐based system for single‐stirred bioreactors and their cascade
Authors: Meyer H.‐D. , Kuhlman W. , Lübbert A. , Schügerl K. 
Published: July 2010

AbstractA computer‐aided measuring and control system for bioreactors is presented. It is suited for the automation of a wide range of different fermenters. The hardware concept as well as the newly developed software package are described. The whole system was tested thoroughly during several yeast cultivation and ethanol production experiments in a single laboratory‐scale stirred tank bioreactor and in a cascade of three stirred bioreactors.
Effect of hydrodynamic stress on dunaliella growth
Authors: Silva Humberto J. , Cortifas Teresa , Ertola Rodolfo J. 
Published: July 2010

AbstractThe effect of hydrodynamic stress derived from gas bubble dispersion and broth mixing on Dunaliella growth was examined by growing the algae in two different vessels; a Roux bottle and a miniloop reactor. It was found that Dunaliella cells were increasingly sensitive to high specific bubble rates at modified orifice Reynolds numbers between 9.9.104 to 18.8.104 and liquid motion with Reynolds numbers between 712 and 1293. The addition of carboxymethylcellulose and agar to the cultures served to protect the microorganisms from the effects of shear stress.
Molecular mechanism of calcium sulfonate redissolution by micelles
Authors: Celik M. S. , Somasundaran P. 
Published: July 2010

AbstractIt has been suggested that redissolution of sulfonate/multivalent precipitates occurs by micellar solubilization. The molecular mechanism governing the redissolution process has not been identified. In this study, the solubilization constant, which is an indicator of the capacity of the micelles to solubilize the precipitate, is determined with the aim of elucidating the molecular mechanism involved in the redissolution process. The effects of ionic strength, alkyl chain length, temperature, n‐propanol and n‐dodecane on the solubilization constant are examined under a variety of conditions. In addition, counter‐ion binding to micelles and conductivity of micelles are determined for different sulfonates. Based on all these data, a mechanism involving the adsorption of Ca2+ on the micelle and the subsequent dissolution of calcium disulfonate to replenish the system is proposed to account for the precipitate redissolution.
Influence of gas distributor design on the oxygen transfer characteristics of an airlift fermenter
Authors: Bovonsombut Sittisin , Wilhelm Anne‐Marie , Riba Jean‐Pierre 
Published: July 2010

AbstractThe performances of two types of gas distributor (a perforated ring and a porous plate) in an airlift fermenter were compared in the measurement of gas holdup, overall mass transfer coefficient and mixing time, using four aqueous media containing different concentrations of four electrolytes, sugar and antifoam agent in order to simulate fermentation media.In pure water, a 50% higher kLa value was found with the porous plate; this difference was emphasized by adding salts or organic compounds so that the kLa could become two or three times higher with the porous plate. The type of sparger seemed to have very little effect on holdup ratios and mixing times.
Continuous‐flow estimation of laccase activity in rotten grape juice by a computerized electrode
Authors: Zouari Nabil , Romette Jean‐Louis , Thomas Daniel 
Published: July 2010

AbstractA continuous‐flow method for estimation of the degree of rot in grape has been developed which involves measuring the oxygen consumption in a mixture consisting of grape juice and quinol. For the automation of the system, assays were carried out with centrifuged and heated samples of grape juices. The feasibility of the system has been demonstrated.
Dissolution kinetics of ulexite in water saturated by sulphur dioxide
Authors: Alkan Mahir , Muhtar Kocakerim M. 
Published: July 2010

AbstractThe dissolution kinetics in SO2‐saturated water of ulexite, a sodium calcium borate, have been studied. The effect of particle size, gas flow rate and temperature were determined. Ulexite dissolution rates increased with decrease in particle size, with increase in temperature and were not affected by the flow rate of SO2. The activation energy for the dissolution was calculated as 58‐01 kJ mol−1.
Recovery of uranium by tannin immobilized on agarose
Authors: Nakajima Akira , Sakaguchi Takashi 
Published: July 2010

AbstractTannin, which is a ubiquitous and inexpensive material, was immobilized on agarose gel to produce an excellent adsorbent for uranium recovery from seawater. Optimal conditions for the immobilization of tannin on agarose gel by both the epichlorohydrin and cyanuric chloride coupling procedures were examined in detail. The resulting immobilized tannin has a highly selective ability to adsorb uranium and applicability in both column and batch systems. This adsorbent can recover uranium from natural seawater with high efficiency. The maximum adsorption capacities were 1850 μg uranium g−1 adsorbent for the tannin immobilized on agarose gel by the epichlorohydrin coupling procedure and 1062 μg g−1 adsorbent for that produced by the cyanuric chloride coupling procedure.
A comparison of immobilised protease activities
Authors: Jasim Munir A. , Hall George M. , Mann John , Taylor Keith D. A. 
Published: July 2010

AbstractFive proteases, bromelain, ficin, papain, pepsin and trypsin were immobilised on cellulose supports by two different techniques using cyanogen bromide or glutaraldehyde. The degree of immobilisation was determined and the activity of the immobilised enzymes compared to that of the free enzymes using egg albumin as a substrate. The stability of each immobilised enzyme was determined by repeated hydrolysis of egg albumin and the most active enzymes used in sequence—the technique of multiple hydrolysis—in order to maximise hydrolysis. In terms of the degree of immobilisation, activity and stability of the enzymes cyanogen bromide was more effective than glutaraldehyde. For the individual enzymes pepsin, trypsin, ficin, bromelain and papain were most active, stable and immobilised to the greatest extent.
Immobilization of glucoamylase in porous glass fibers
Authors: Toldrá Fidel , Jansen Norman B. , Tsao George T. 
Published: July 2010

AbstractGlucoamylase has been successfully immobilized in controlled pore glass fibers by a silane‐glutaraldehyde coupling method. Enzyme solution was continuously recycled through the glass fibers held in a fixed bed reactor. Different process parameters were tested. Reservoir volume and initial enzyme concentration both had a strong influence on final glucoamylase loading. The recycle rate affected the rate of loading but not the final amount of loaded enzyme. Glucoamylase was found to be nonuniformly distributed within the fibers with penetration depths never higher than 5.75 μm, half of the fiber radius. This factor could be important in improving the immobilized glucoamylase hydrolysis of dextrin syrups.
Scottish shale oil—production, occupational exposure and health effects
Authors: Scott Carleton B. , Irish Glenn E. 
Published: July 2010

AbstractExpansion of shale oil production to commercial scale in Colorado, USA required an investigation of potential adverse health effects that could result from exposure to raw shale oil, intermediate streams and final products. Comparison of Scottish shale oil products, operations, occupational exposures and adverse health effects with shale oil products and operations planned for Colorado showed the importance of severe hydro‐treating of raw shale oil to remove biologically active molecules (believed to be mainly aromatic heterocyclics) that apparently were responsible for most of the adverse health effects experienced by Scottish shale oil workers, neighbors and users.
A simple model for the reaction of normal octane on pt/al2o3 catalyst
Authors: Ako Churchill T. , Susu Alfred A. , Gobina Edward N. 
Published: July 2010

AbstractDesign parameters were obtained from a simple model developed for the catalytic reaction of normal octane on platinum—alumina catalyst. The relevant equations were solved analytically and graphically. The model did not involve intramolecular and intermolecular mass transfer phenomena because of the particle size (0.1–0.4 mm); it took into account kinetic phenomena and was applied in predicting conversion—temperature and conversion—reactor length profiles. Conversion—temperature profiles obtained from the model compared favourably with those obtained experimentally.
Hydrolysis of sugar cane bagasse with hydrochloric acid: Separation of the acid by pervaporation. Evaluation of the bergius process
Authors: Schuchardt Ulf , Joekes Inés , Duarte Humberto C. 
Published: July 2010

AbstractPolyester reinforced PTFE membranes with a nominal pore size of 0.02 μm are very effective in pervaporating HCl gas from hydrochloric acid solutions and cellulose hydrolysates. The efficiency of such membranes, which may be as high as 1.8x10−2 mmol HCl min−1 cm−2 at 40°C, is almost independent of the flow rate and the static pressure of the acidic solution but depends strongly on the acid concentration. At an acid concentration of 26% (w/v) the pervaporation of HCl is negligible at 40°C, but can be accelerated by increasing the temperature. A slow increase of temperature during the pervaporation process is proposed, as this promotes post‐hydrolysis of the sugars. Lithium chloride induces structural changes in the membrane which increase efficiency without compromising performance. The use of this new technology in conjunction with the original Bergius process could improve the performance of the latter and reduce its overall costs. The use of the improved process for the hydrolysis of sugar cane bagasse could double the yields of sugar or alcohol per hectare of planted sugar cane.
Fractionation of dextran using repetitive batch chromatography
Authors: Barker P. E. , England K. , Ganetsos G. 
Published: July 2010

AbstractThe fractionation of broad dextran fractions using preparative scale gel permeation chromatography has been carried out. A batch system was used, consisting of ten borosilicate columns, each of 5.1 cm i.d. and 70 cm long and packed with Spherosil XOB075 porous silica beads.The repetitive injection technique was employed and the effects of feed, charge volume and concentration on the molecular weight distribution of the products were evaluated.
Acid catalysed pressure synthesis of n‐ethylbenzylamine from benzylamine and ethanol
Authors: Deka Dibakar C. , Nandi Dilip K. , Palit Sunanda K. 
Published: July 2010

AbstractThe synthesis of N‐ethylbenzylamine from benzylamine and ethanol in the presence of an acid catalyst has been carried out under pressure. Under optimum conditions (497 K, 6.3417 MPa, residence period 1 h, benzylamine to ethanol mol ratio 1:3 and benzylamine to hydrochloric acid mol ratio 1:1), the conversion of benzylamine to N‐ethylbenzylamine is 78.39%.
Air‐lift reactors in chemical and biological technology
Authors: Merchuk Jose C. , Siegel Marc H. 
Published: July 2010

AbstractThe principle of the air‐lift reactor is finding wide application in the fields of both chemical technology and biotechnology because it offers simple and effective mixing in three‐phase processes involving gases, liquids and solids. The air‐lift principle offers advantages of no moving parts, high gas absorption efficiency, good heat transfer characteristics and rapid mixing which are applicable in a range of industrial processes. This review considers specific aspects of air‐lift reactors emphasizing their function and relevance to particular applications. The two main groups of air‐lift reactor, baffled vessels and external loop reactors, have four main component parts in common, the riser, the downcomer, the base and the gas separator, all of which have distinct characteristics. The performance of these four components with respect to flow configurations, fluidization of suspended solids and mass transfer are discussed together with methods of evaluating mass transfer coefficients.
The effects of oxygen on β‐lactam biosynthesis by alginate entrapped streptomyces clavuligerus
Authors: Scott Robert I. , Sladen Susan , Maidment Mandy , Rashid Tahira , Pratsis Christos , Perry David 
Published: July 2010

AbstractThe physiology of Streptomyces clavuligerus has been studied by investigating oxygen uptake and β‐lactam (clavulanic acid) production by free and alginate entrapped cells. The specific oxygen uptake rate of cells entrapped in strontium or calcium alginate was only about 35% of the rate in free cells. This reduction in oxygen uptake was due to reduced internal diffusion of oxygen; in addition calcium, barium and strontium ions could also cause oxygen uptake in free cells to be inhibited. Measurements of the deformation of individual gel beads showed that maximum hardness was reached after 15 min exposure to 0.14 mol dm−3 Ca2+. Exposure of cells to Ca2+ for this time caused a 15% reduction in the rate of oxygen uptake. Levels of clavulanic acid produced by free cells were higher than those produced by immobilized cells; production was dependent on the degree of aeration of the cells.
Batch alcoholic fermentation modelling by simultaneous integration of growth and fermentation equations
Authors: Gòdia F. , Casas C. , Solà C. 
Published: July 2010

AbstractThe modelling of batch growth and fermentation data presents important disadvantages when numerically calculated specific rates are used. In this paper, the results obtained using a different technique, based on the integration of the differential rate equations in the modelling of batch alcoholic fermentation with Saccharomyces cerevisiae at different temperatures and initial sugar concentrations, are presented, and the use of both techniques is discussed.
Production of protease by bacillus subtilis using simultaneous control of glucose and ammonium concentrations
Authors: Kole M. M. , Draper I. , Gerson Donald F. 
Published: July 2010

AbstractBatch, ammonium‐controlled and simultaneous glucose and ammonium controlled fermentations were compared for the production of protease by Bacillus subtilis NCIB 8054. During fermentations of B. subtilis, maximum protease production was obtained in the stationary phase. Protease production in fermentations controlled at 5 mmol dm−3 ammonium was 1.5 times greater than in uncontrolled batch fermentations. Simultaneous control of ammonium at 5 mmol dm−3 and glucose at 0.15 g dm−3 using controllers based on an ammonium electrode and an oxygen electrode, doubled protease production compared with fermentations having only an ammonium control and tripled protease production compared with uncontrolled batch fermentations. The protease yield on glucose and protease yield on ammonium was increased in fermentations with simultaneous glucose and ammonium control.
Studies on sulphatization—I. Sulphatization of manganese ore with pyrite
Authors: Nayak Binod Bihari , Parida Kulamani , Rao Sreepada Bhanojee 
Published: July 2010

AbstractThe sulphatization of low grade manganese ore with iron pyrites has been studied. The effect of reaction period, temperature, ratio of manganese to sulphur, particle size, surface area and packing density was investigated and the extent of sulphatization was reported as recovery of manganese sulphate. Under optimum heating time of 2 h at 600°C with finely powdered (−150±200 mesh BSS pyrite and −300±325 mesh manganese ore) reactants, the conversion to manganese sulphate was 82%.
A continuous‐flow method for the rapid determination of sanitary quality of grape must at industrial scales
Authors: Zouari Nabil , Romette Jean‐Louis , Thomas Daniel 
Published: July 2010

AbstractA rapid method for the continuous‐flow determination of laccase activity in grape must has been developed. The system was automated and permitted online measurement with less than 5% error.The feasibility of the system in industrial conditions was proved in vinification plants with grape musts and wines. The capacity of musts to consume oxygen during sulphur dioxide treatments was also followed.