bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absorption of carbon dioxide in ethylenediamine solutions i. absorption kinetics and equilibrium
Authors: Weiland R. H. , Trass Olev 
Published: March 2009

AbstractThe chemical absorption of carbon dioxide by a laminar jet of ethylenediamine has been studied at 25.5°C under pseudo‐first‐order kinetic conditions. The reaction was found to be second‐order with a rate constant of 1.0 x 105 1/g. mole sec. Equilibrium calculations at 18°C indicate that the partial pressure of carbon dioxide is very low, even over highly carbonated ethylenediamine solutions. The effects of amine concentration and carbonation ratio on the physical solubility and diffusivity of carbon dioxide in solution were inferred from corresponding results for nitrous oxide
Rates of reaction of SO2 with metal oxides
Authors: Deberry David W. , Sladek Karl J. 
Published: March 2009

AbstractRates of sorption of SO2 from synthetic flue gas by 14 metal oxides were determined. These oxides had been selected for their potential applicability to processes for removing SO2 from flue gas using thermal regeneration of sorbent. Measurements were performed using thermogravimetric analysis, and rates were fitted to semi‐empirical expressions; CeO2, Co3O4, Cr2O3, CuO, Fe2O3, and NiO displayed measurable rates in the range 200° to 500°C, and were converted to sulphates. Rates were immeasurably small at 25° to 800°C for Al2O3, Sb2O5, SnO2, TiO2, V2O5, WO3, ZnO, and ZrO2, CuO and CeO2 showed the highest rates
Optimisation d'un réaacteur multiéatagéa d'oxydation de l'anhydride sulfureux au moyen de trois méthodes directes (hooke et jeeves, rosenbrock, simplex).
Authors: Brusset H. , Depeyre D. , Boeda M. , Melkior R. , Staedtsbaeder J. L. 
Published: March 2009

AbstractIn the optimal design of multistage reactors for oxidation of sulfur dioxide, two important cost factors are considered: catalyst and heat exchange. The way to obtain the associated economic function is presented. A complete solution of the reactor train equation must be carried out to obtain each value of this implicit function of ten variables (injections of gas and temperatures in catalyst beds). To optimize the multistage reactor, three direct methods are adapted for a specific treatment of constraints on the variables. Two of these methods (Hooke and Jeeves, simplex) give satisfactory results and it appears possible to make a rational choice between exchangers and injections
The reduction of ferrous chloride with hydrogen
Authors: Miriyala V. R. R. , Bowen J. H. 
Published: March 2009

AbstractSingle pellet studies of the kinetics of reduction of ferrous chloride in hydrogen indicate that a significant resistance exists to diffusion of gases through the particles of which the pellets are composed. Experiments carried out at temperatures low enough for chemical reaction to be controlling enabled an activation energy of 39 k cals/g mole of ferrous chloride to be calculated
Laminar and turbulent entry flow of polymer solutions
Authors: Seyer F. A. , Catania P. J. 
Published: March 2009

AbstractEntry lengths and contraction losses have been determined for 0.01, 0.2 and 0.6% aqueous solutions of Separan AP‐30. The Reynolds numbers ranged between 102 and 105 in 1/2‐in. and 2‐in. tubes. At Reynolds numbers in excess of 2100, the entry lengths and contraction losses for the polymer solutions are significantly larger than those for Newtonian fluids. These effects are shown to be related to the transitional flow phenomena which occur with drag reducing polymer solutions.At low Reynolds number the contraction loss data show expected trends but are in quantitative disagreement with predictions based on recent studies in capillary tubes. These indicate that the analyses based on small tubes are less general than anticipated.
Drop size in power law non‐newtonian systems
Authors: Skelland A. H. P. , Raval V. K. 
Published: March 2009

AbstractDrop volume studies were made by forming non‐Newtonian pseudoplastic drops in a continuous toluene phase and chlorobenzene drops in non‐Newtonian continuous phases. Combination of results for these cases enabled development of a correlation for the prediction of non‐Newtonian drop volume in a non‐Newtonian continuous phase. The development is confined to power law fluids and provides expressions for both long and short nozzles in terms of a two‐stage drop formation process. Variables included nozzle size, formation time, and rheological properties from eight non‐Newtonian systems in a program of 144 runs.
Statistical evaluation and design of an evaporator control system
Authors: Bacon David W. , Howe Gerald L. 
Published: March 2009

AbstractThe utility of a statistical procedure suggested by Box and Jenkins is assessed for the evaluation and modification of an industrial evaporator control system. Results, obtained from the analysis of routine unperturbed operating data, indicate that this approach is (i) readily adaptable to the analysis of the dynamic behaviour of a full scale chemical unit process, (ii) characterized by effective model form identification, and (iii) extremely useful in deriving conventional and more novel control functions to supplement existing control schemes.
Drag reduction and turbulence modification in rigid particle suspensions
Authors: Pirih R. J. , Swanson W. M. 
Published: March 2009

AbstractTurbulent drag reductions on the order of 50% were obtained for pipe flow of submicron, rod‐like particle suspensions at weight concentrations of less than 0.5%. Wall Reynolds numbers as high as 40,000 were obtained for the suspensions. The suspended particle configuration was rigid and non‐elastic and was not affected by local strain rate fields. Longitudinal turbulence data are presented for two suspensions and for the Newtonian solvent at an average flow velocity of about 7 fps. Distinctly modified turbulence generation and dissipation were observed. The suspension exhibited smooth transitional flow behavior and increases in both macroscale and microscale. A particle length effect, or relaxation time effect, was observed with the larger relaxation time suspension exhibiting the more extreme flow and turbulence differences.
Aerosol particle collection in a vertical pneumatic transport line
Authors: Behie S. W. , Beeckmans J. M. , Knetting P. , Bulani W. 
Published: March 2009

AbstractA vertical pneumatic transport line was found to be an efficient collector for 2.4 micron magnesium sulphate particles. Glass beads of average diameter 310 microns and 514 microns, lightly coated with a non‐volatile oil, were used as collector particles. The experimental results were in satisfactory agreement with a theoretical analysis based on an idealized single collector particle model. Electrostatic charging of the aerosol prior to entry of the collector particles did not materially alter the bead collection efficiency, with or without radial electric field in the transport line.
Multi‐component reboiled absorber modeling and parametric studies
Authors: Prowse D. R. , Johnson A. I. 
Published: March 2009

AbstractThe steady state operation of an industrial multi‐feed, multi‐component reboiled absorber column which was previously investigated by Petryschuk (1964) has been simulated by two alternate mathematical models — an equilibrium stage model and a tray efficiency model based on the Murphree tray efficiency concept. Development of the models required the use of a set of physical property estimation procedures which differed from those used by the previous investigator. When subjected to parametric variation studies, both new models successfully reproduce known quantitative and qualitative behavior attributed to the column. The study results demonstrate not only the sensitivity of a simulation of a multicomponent separation process upon physical property estimation procedures, but also indicates the difficulty in model discrimination when plant data of only limited range and accuracy is available.
Momentum transfer in a horizontal liquid‐jet ejector
Authors: Bhat P. A. , Mitra A. K. , Roy A. N. 
Published: March 2009

AbstractThe performance of a horizontal liquid‐air ejector system was greatly enhanced by creating mixing shock. Principles of macroscopic momentum and energy balances were employed to define an overall loss factor which was found to be a useful correlating parameter in the case of homogeneous bubble flow. Empirical correlations are proposed to predict mass ratio as a function of different parameters.
Holdup in vertical two and three phase flow Part I: Theoretical analysis
Authors: Bhaga D. , Weber M. E. 
Published: March 2009

AbstractA general one‐dimensional theory for predicting the average holdup or column concentration in three phase flow is formulated. The analysis takes into account the local relative velocity between the phases, the non‐uniform flow and holdup distribution across the column, and the effect of the concentration of the dispersed phase on the relative velocity. The present theory is compared with the previous analyses for two phase flow reported in the literature and it is shown that all of them are special cases of the general theory proposed here.
Effect of ultrasonic waves on the activity of chromia‐alumina catalyst
Authors: Mathur Indresh , Bakhshi N. N. , Mathews J. F. 
Published: March 2009

AbstractIt has been found that the supported metal catalyst, chromia on alumina, prepared in the presence of ultrasonics (90 kHZ) is a more active catalyst for the decomposition of hydrogen peroxide (8N aqueous solution) than the catalyst prepared in the absence of ultrasonics. The catalyst preparation consisted of insonation for one hour during the impregnation stage and subsequent drying and calcination. The activity measurements were carried out at 25, 30, 40, 50 and 60°C in a batch reactor. The higher activity of the insonated catalyst has been explained on the basis that chromia is better dispersed on alumina in case of the insonated catalyst. The conclusion for the better dispersion of metal in the insonated case is based on BET surface areas and pore volumes and on electron microprobe analyser measurements of chromium metal distribution.
Suboptimal control of chemical engineering systems
Authors: Cormack D. E. , Luus Rein 
Published: March 2009

AbstractTo greatly simplify the two point boundary value problem encountered in optimization, the n‐dimensional state space is mapped into a scalar V‐domain by the quadratic transformation

as suggested by Schlossmacher and Lapidus. When Pontryagin's maximum principle is then applied to the system in this V‐domain, the two point boundary value problem contains only a single scalar adjoint equation.A new computational form for the adjoint equation and an efficient a priori method of determining an effective Q are presented. The two point boundary value problem is solved by choosing the initial value of the adjoint variable that minimizes the performance index. A straightforward numerical minimum seeking procedure is used to locate this adjoint.Evaluation of this suboptimal procedure with respect to the optimization of a linear gas absorber, a nonlinear CSTR and a plug flow reactor shows that such a procedure yields results close to the optimal.
Nonlinear parameter estimation and model distinguishability of physicochemical models at chemical equilibrium
Authors: Blau G. E. , Klimpel R. R. , Steiner E. C. 
Published: March 2009

AbstractThe problem of estimating parameters and distinguishing between rival mathematical models describing complex chemical equilibrium systems is formulated from first principles. Using basic statistical and optimization theory, a methodology is developed for handling these systems. To illustrate its usefulness, the technique is applied to the conductivity study of solutions of alkali metal alkoxides in dimethyl sulfoxide. The method is relatively involved and its use is warranted only in complex physical systems which do not lend themselves to simplification by standard procedures.
Friction in turbulent flow of solids‐gas systems
Authors: Peters Leonard K. , Klinzing George E. 
Published: March 2009

AbstractTwo‐phase solids‐in‐air flow was experimentally studied in a once‐through circular tube flow system using nominal 25μ and 50μ spherical glass beads. At mass flow ratios up to 1.6, the friction factor was found to be generally higher than that for air flow alone but considerably less than that for a single‐phase fluid having a density the same as that of the mixture.The pressure drop experienced by the 2 phase system of 25μ beads and air was found to show true drag reduction.A continuum mechanics analysis showed the viscous stresses and Reynolds stresses to be significantly affected by solid particle addition.
A gas chromatographic method for the determination of mass‐transfer resistances in zeolite catalysts
Authors: Macdonald W. R. , Habgood H. W. 
Published: March 2009

AbstractThe various mass‐transfer resistances that occur in a packed bed of zeolite granules contribute to the gas chromatographic “C” terms that determine the relative width (or second moment) of a gas chromatographic peak. It was assumed that mass transport in the micropores of the crystallites was independent of the nature of the carrier gas. From measurements with hydrocarbon pulses in hydrogen and nitrogen carrier gases, it was possible by the method of Giddings and Schettler to separate the gas phase resistances from the micropore resistances. Data are given for benzene, n‐octane and (in part) n‐decane on Na × zeolite at 370, 400 and 430°C. Experimental difficulties and precautions are discussed.
Salt effects in liquid‐vapor equilibrium: A new equation for the ethanol‐water system saturated with salt
Authors: Jaques D. , Furter W. F. 
Published: March 2009

AbstractA new equation for salt effect in vapor‐liquid equilibrium is presented, which correlates temperature and the liquid‐phase concentrations of all three components with equilibrium vapor composition, for isobaric systems consisting of a binary to which • salt has been added to saturation. The equation, of form

was tested successfully with literature data for 12 ethanol‐water‐salt systems, yielding a better fit for all 12 systems than the one‐constant equation of Johnson and Furter, and with the confidence level for the comparison in excess of 99.9% for six of thesystems tested.
Optimal state changeover control of a multivariable system using a minicomputer
Authors: Jarvis R. C. F. , Wright J. D. 
Published: March 2009

AbstractA study of the application of the calculation and implementation of an open loop optimal changeover policy for a multivariable system on a minicomputer has been made. If the required changeover time and control time interval have been specified, a switching policy for the controls may be calculated using standard linear programming techniques. The multivariable system was an analog computer simulation of a liquid‐liquid extraction column.By repeated use of the procedure with different overall changeover times, a “best” changeover policy could be determined. The criterion for this policy was a minimum changeover time with the restriction that the sum of squared errors between the required and actual final states was less than a specified small value. Practical as opposed to theoretical small values of this error criterion were used.
Counter‐current solid liquid extraction in a cascade of batch extractors
Authors: Plachco F. P. , Lago M. E. 
Published: March 2009

AbstractAn analytical solution and method of calculation is presented for a cascade of N perfectly mixed batch extractors operating counter‐currently, for spherical solid particles, with parameters which may vary for each extractor.The results for the case of constant and equal parameters along the complete cascade are presented in dimensionless plots; N varies from 1 through 10.The practical interest of these diagrams lies in their use in design and/or in foreseeing the behavior of a cascade when its parameters undergo variations.A sample calculation is included.
Batch separations with tails recycle
Authors: Colbert John W. 
Published: March 2009

AbstractThis study develops material balance calculation techniques for repetitive batch separation processes in which the tails stream is collected in fractions which are recycled to the next batch at appropriate intervals.Criteria for selecting the fraction sizes which minimize total separative work per unit of products are determined. In the electrolytic rectification of a D2O‐H2O mixture from 20 to 99.8% D2O at a separation factor of 11, for example, three fractions thus selected are adequate and the separative work is considerably less than that of the more conventional cascade system.
Process design considerations and steady‐state operational data for the separations of isotopes of oxygen
Authors: Wolf D. , Cohen H. 
Published: March 2009

AbstractOperational data for the separation of oxygen isotopes are given on flow rates, concentrations and concentration profiles of the isotope separation plant of the Weizmann Institute of Science which has reached steady‐state operational conditions with regard to the rare and more difficult to separate oxygen‐17 isotope. This plant consists of two sections, namely packed distillation columns and thermal diffusion columns. Data on the columns and packing characteristics are given. The concentrations reached in the distillation section are up to 98% of oxygen‐18 and up to 20% of oxygen‐17. In the thermal diffusion section, concentrations of oxygen‐18 up to 99.9% and of oxygen‐17 up to 96% have been attained.
The transient behavior of an ethane dehydrogenation furnace
Authors: Li M. C. , Johnson A. I. 
Published: March 2009

AbstractA mathematical model of the transient behavior of an existing ethane dehydrogenation furnace is discussed. The correlation of pressure drop with time has been found from the available data. The fractional carbon deposition and the multiplier coefficient of a pressure drop equation have been determined by the direct search optimization technique of Hooke and Jeeves.A considerably improved policy for the operation of the furnace was determined by considering plant temperature profile and hydrocarbon/steam ratio as parameters for maximizing average ethylene produced per day. The effect of temperature profile on the distribution of carbon deposited along the reactor was also predicted and discussed.
Identification of one phase flow processes
Authors: Malpani S. N. , Donnelly J. K. 
Published: March 2009

AbstractA method is presented for the identification of parameters in the partial differential equations describing the dynamic behaviour of a certain class of one phase flow processes. Included in this class of processes are certain types of heat exchangers and flow reactors in which axial and radial dispersion are not important. The approach employed is to reduce the partial differential equations to an extended system of ordinary differential equations with the method of characteristics. Once in this form the method of quasilinearization is employed to identify the parameters in these ordinary differential equations.
Vertical pneumatic conveying: An experimental study with particles in the intermediate and turbulent flow regimes
Authors: Capes C. E. , Nakamura K. 
Published: March 2009

AbstractVertical pneumatic conveying was studied in a 3‐inch diameter riser 30 feet in length using solids ranging in particle Reynolds number from 100 to 3500. Particle to gas mass flow ratios varied from 0 to 8 and pipeline conditions extended from dilute flow down into the choking region.Average particle hold‐up was determined by means of a series of quick‐closing valves and particle slip velocity was often found to be greater than the calculated terminal velocity. The reasons for this are examined.Frictional pressure losses in the riser were also determined and compared with literature data. The phenomenon of choking is considered briefly.
Statistical thermodynamics of group interactions in n‐alkanone pure liquids and solutions
Authors: Lee Tsung‐Wen , Greenkorn Robert A. , Chao Kwang‐Chu 
Published: March 2009

AbstractThe statistical thermodynamics of group interaction previously developed for liquids of chain molecules is extended to their mixtures. The theory is applied to pure n‐alkanone liquids, and solutions of n‐alkanone/n‐alkanone and n‐alkane/n‐alkanone systems. The interaction properties of methyl and methylene groups are taken from our previous work. The interaction properties of carbonyl group are determined and reported in this work. The calculated density and heat of vaporization of pure n‐alkanone‐2 liquids agrees with data over a wide temperature range. The calculated heats of mixing of n‐alkanone/n‐alkane and n‐alkanone/n‐alkanone solutions agree with available data.
Tracer measurements in two phase annular flow to obtain interchange and entrainment
Authors: Jagota A. K. , Rhodes E. , Scott D. S. 
Published: March 2009

AbstractExperimental methods are described which yield information on entrainment and liquid interchange in two phase annular flow by using a model based on the response of the system to a steady injection of tracer in the film. Independent measurements of entrainment are also reported. The results indicate that if care is taken to ensure uniform continuous tracer injection and correct response measurement, it is possible to obtain reasonable values of the entrainment and interchange parameters. The annular flow model presented in an earlier paper1 appears to give a useful description of the interchange process.
Influence d'une agitation rotative sur le mélange en retour dans une colonne pulsée à plateaux perforés
Authors: Barame S. , Molinier J. , Angelino H. 
Published: March 2009

AbstractSi l'on superpose une agitation rotative à l'agitation produite par la pulsation dans une coloune à plateaux perforés on obtient de meilleures efficacités surtout pour des valeurs du produit A.f assez faibles. Les auteurs ont mesuré experimentalement la rétention et le nombre de Péclet dans ce nouvel extracteur afin d'en déduire le coefficient de mélange en retour de la phase continue.En comparant leurs résultats avec ceux que l'on obtient dans une colonne pulsée standard ils montrent que l'amélioration d'efficacité doit ětre attribuée à l'augmentation de rétention et non pas, comme on pouvait le penser, à la diminution du mélange en retour.
Élements de calcul des colonnes de fractionnement par moussage continu
Authors: Rovstan M. , Roqves H. 
Published: March 2009

AbstractOn étudie le fractionnement par inoussage consider comme une operation unitaire. Une théorie basée sur l'analyse dimensionnelle, permet de calculer le fonctiomnement des colonnes en continu. On évalue numériquement le taux de reflux interne R1 résultant de l'instabilité de la mousse. On introduit les notions de productivité spécifique P* de la colonne et d'apport énergétique spécifique E*. Une relation est établie pour corréler P* et les paramètres caractérisant la géométrie (diamètre de colonne, hauteur de mousse) et son mode opératoire (débit d'air, taux de reflux externe, débit d'alimentation, concentration d'alimentation, niveau d'alimentation).
Catalytic reduction of nitric oxide in low concentration high velocity gas streams
Authors: Lamb A. , Tollefson E. L. 
Published: March 2009

AbstractA catalytic micro‐reacting system and a gas chromatographic analytical method were used to investigate the effectiveness of metal alloys in the catalytic reduction of nitric oxide by hydrogen. Oxidative pretreatment significantly increased the catalytic activity. The rate of nitric oxide removal was directly proportional to hydrogen concentration but independent of nitric oxide concentration. Temperatures were 378 — 500°C, space velocities 42,000 — 54,000 hr−1 and hydrogen and nitric oxide concentrations 400 — 55,000 ppm and 600 — 6,800 ppm, respectively. The data support a mechanism involving adsorbed nitric oxide and hydrogen molecules, the rate determining step being the collision of the latter with the catalyst surface. Some selectivity towards nitric oxide reduction in the presence of oxygen was observed.