摘要:

AbstractExperiments on the separation of hydrogen isotopes were conducted using vanadium hydride in a temperature swing process. Process behavior followed trends predicted by an equilibrium theory of process operation, but was modified by a kinetic isotope effect and by finite rates of hydrogen absorption and isotope exchange.

ISSN:0001-1541    

DOI:10.1002/aic.690280102

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractTo study the effect of H2O2on NO reduction with NH3, the homogeneous gas phase reaction of NH3NOH2O2O2was investigated in a Pyrex flow reactor over the temperature range from 500°C to 600°C under one atmospheric pressure. H2O2accelerated the NO reduction by NH3and caused it to be induced at a temperature of 500°C. In the absence of O2, NOx reduction ratio of more than 90% was obtained for NH3/NO5 and H2O2/NO1 at 550°C. In the presence of O2or an excess of H2O2, two side reactions, which cause the NOx reduction ratio to decrease, occur.One of the side reactions is NO oxidation with H2O2. It was found experimentally that NO2inhibited NO reduction and that H2O2was an NO oxidizing agent, as well as an NH3decomposing agent. The other side reaction was the formation of NO and NO2, which resulted from the oxidation of NH3with O2. Under the conditions of our experiments, the amount of O2in our reaction system was extremely high compared to the amounts of NO, NH3and H2O2in the system. Thus NOxwas assumed to be produced by the oxidation of the NO reducing radicals, which were produced by the reaction of

ISSN:0001-1541    

DOI:10.1002/aic.690280103

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractA fast and accurate method was developed for the integration of large sparse systems of stiff initial value ordinary differential equations. The system is ordered, decoupled and, if necessary, torn into subsystems (also called blocks) which are then solved by orthogonal collocation on finite elements. The size of these elements, or steps, is different for each subsystem and is a function of the stiffness of the set of equations constituting the subsystem. The steps are overlapped for maximum computational efficiency.

ISSN:0001-1541    

DOI:10.1002/aic.690280104

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractThe statistical behavior of some common parameter estimation methods is investigated by simulation. The methods based on the maximum likelihood principle give the best estimates of parameters in a given model. An analysis of the possibilities for detecting systematic errors by means of the maximum likelihood method showed that this method gives at best the same information as other well known tests.

ISSN:0001-1541    

DOI:10.1002/aic.690280105

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractIn a previous paper, a theoretical model of venturi scrubber performance was presented in which the operating variables, scrubber geometry, and droplet and dust size distributions are specified. The present paper examines the roles that heat and mass transfer have in determining the particle collection efficiency. The mechanisms of inertial impaction, interception, and diffusiophoresis are analyzed simultaneously to account realistically for heat and mass transfer effects on particle collection. Operation at elevated gas temperatures can substantially reduce collection, primarily due to the increase in gas density which occurs as the gas contacts the spray liquid. Mass transfer effects are important only when condensation onto the drops occurs, such as that during the scrubbing of saturated gas streams or when using cold liquid sprays. Under these conditions, mass transfer effects increase the collection efficiency.

ISSN:0001-1541    

DOI:10.1002/aic.690280106

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractA mathematical model for simulating particulate removal in gas‐solid fluidized beds is developed based on bubble assemblage concepts and particulate collection mechanisms. The importance of fluidization mechanics on the overall fluidized bed filtration performance is emphasized in the present study. Model predictions of fluidized bed filtration efficiencies are shown to compare favorably to the experimental results of various investigations. Because of the general formulation of the proposed model, it is believed to be applicable in the design of fluidized bed filtration operation

ISSN:0001-1541    

DOI:10.1002/aic.690280107

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractAn approximate method is developed for the simulation of three‐phase, multistaged multicomponent separators in which one of the two liquid phases can be regarded as being constituted of almost one component only.Comparisons with the complete three‐phase model shows a large reduction of the required computation time and a satisfactory agreement of the obtained resu

ISSN:0001-1541    

DOI:10.1002/aic.690280108

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractThe transient thermal response of a power‐law type non‐Newtonian, laminar boundary layer flow over a wedge is investigated. Consideration is given to the case of a step change in surface temperature. Details of the transient heat flux and the temperature field are obtained and have been presented graphically. The range of Prandtl numbers investigated is from 5 to 1000 while the viscosity index was allowed to vary from 0.1 to

ISSN:0001-1541    

DOI:10.1002/aic.690280109

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper is concerned with an important aspect of process control design—synthesis of the control structure. Synthesis of control structures has long been practiced by experienced control engineers, who relied on intuition, insight and judgment to pick a feasible solution from the vast number of alternatives that were possible. This paper describes a systematic procedure to generate these alternatives based on the cause‐and‐effect representation of the process. The final product is a set of control schemes from which the final system may be selected or evolved. The work is significant in that it is the first attempt to apply non‐numerical problem‐solving techniques to the problem of synthesizing process control structures. As such, it gives a new way of studying and teaching chemical proces

ISSN:0001-1541    

DOI:10.1002/aic.690280110

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY

摘要:

AbstractA new process for purification of phenolic wastewaters by parametric pumping is presented.An equilibrium (linear) model for nonmixed dead volumes thermal direct mode parametric pumping is developed and the influence of bottom and top dead volume magnitudes on transient separation is analyzed.Analytical solutions for batch, continuous and semicontinuous operations are presented.Experimental data on the system phenol/water‐Duolite ES861 include equilibrium isotherms at 20°C and 60°C and parapump runs for the cases mentioned ab

ISSN:0001-1541    

DOI:10.1002/aic.690280111

出版商:American Institute of Chemical Engineers    

年代:1982

数据来源: WILEY