摘要:

AbstractPenetration theory solutions are provided for gas absorption with or without a (pseudo) first‐order irreversible chemical reaction in cocurrent and countercurrent flow wetted‐wall columns, taking into account a constant gas‐film resistance as well as the axial decrease in gas composition due to absorption, while assuming non‐rippling laminar flow for the liquid phase and plug flow for the gas phase. Limiting solutions are also obtained for situations when either the gas phase resistance or the axial variation of gas composition is negligible. The results are suitable for ϕ ≥ 3 and can be used for both Newtonian and non‐Newto

ISSN:0008-4034    

DOI:10.1002/cjce.5450620112

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThe pressure drop and liquid and slurry phase holdups of a cocurrent flow of gasNdashoil and gasNdashcoalNdashoil slurry mixture in cylindrical columns (1.85 and 2.85 cm‐ID) were investigated. The effect of viscosity (43.1‐315 cp) was determined using solutions of two different mineral oils and of four different concentrations of coalNdashoil mixtures.The liquid and slurry holdups increased with liquid flowrate and liquid viscosity and decreased with gas flow rate. For solid concentrations in the range 0‐35 wt% with the size of coal employed (0.07‐0.16 mm) the slurry behaved like a homogeneous Newtonian fluid. The data for frictional pressure drop and phase holdups were correlated in terms of the ratio of fluid velocity, and the Reynolds and Weber numbers of the liquid and slurry

ISSN:0008-4034    

DOI:10.1002/cjce.5450620113

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThe pressure drop and separation efficiency were measured of a hydrocyclone operating under flooded underflow or no air‐core conditions. The solids were glass spheres with a geometric number average diameter of 13 μm and a geometric standard deviation of 1.69. Water was the fluid. Other fixed variables included the solids feed concentration of 2265 mg/L, the glass hydrocarbon configuration following the optimal Rietema recommendations and the temperature. The variables were feed flowrate 0.44 to 0.63 L.s1and volume split of 2.4:1 to 6.1:1; a factorial design was used.The pressure drop, ΔPs, was 4 to 7 times larger than that expected for air core operation and was correlated in terms of the capacity ratio Q/(ΔPs)0.47. The pressure drop was relatively independent of volume split.The separation efficiency was a much stronger function of volume split than of feed flowrate. The Dp(50)diameter at a feed flowrate of 0.63 L.s−1lies between 4.3 to 9.2 μm; of the seven correlations available for predictingDp(50), the approach of Rietema (1961) gives the best results. The experimentally measured reduced efficiency was less sharp than that reported by Yoshioka and Hotta (1955) and by the theory of Uematu et al.

ISSN:0008-4034    

DOI:10.1002/cjce.5450620114

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractGas‐liquid chromatography was employed to determine the activity coefficients of NO2and SO2at infinite dilution in methanol. The infinite dilution activity coefficients at 301.2 K were found to be 15.5 ± 0.1 and 0.491 ± 0.055 for the systems NO2‐methanol and SO2‐methanol, respectively. These values were subsequently used along with the single parameter Wilson equation to predict vapor‐liquid equilibrium data for the systems NO2‐N2‐methanol and SO

ISSN:0008-4034    

DOI:10.1002/cjce.5450620115

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractA new method for the evaluation of kinetic parameters is proposed, in which differential thermal analysis (DTA) is carried out under psuedo‐isothermal conditions, that is, both sample and reference materials are not heated and the temperatures remain as isothermal as possible. The hydrolysis of acetic anhydride was used as a model of simple reaction for the DTA experiment. The kinetic parameters such as the rate constant, the heat of reaction and the activation energy, evaluated from the proposed method were in good agreement with those obtained from conventional titration measurements. Systematic errors in the rate constant evaluation are discussed in order to enable the kinetic parameters to be evaluated accuratel

ISSN:0008-4034    

DOI:10.1002/cjce.5450620116

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThe complex reaction between urea and formaldehyde is studied by the simultaneous method of DTA in pseudoisothermal state and conventional titration, and the kinetic parameters and the heat of reaction are evaluated. This reaction is technically important in the production of urea‐formaldehyde resins. The conversions were determined from both the experimental DTA data and the concentration change of formaldehyde with time. By using the available values of the heat of reaction, the rate constants then could be obtained. The experimentally determined activation energies were in good agreement with those reported in the literatur

ISSN:0008-4034    

DOI:10.1002/cjce.5450620117

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThe continuous and semi‐batch production of the antibiotic patulin by immobilizedPenicillium urticaecells in a three phase fluidized bed reactor was investigated. A key factor for the success of the process was the limitation of the nitrogen source which increased the longevity of the biocatalyst while keeping cell growth at a low level. The continuous reactor was operated for 360 h during which time the effluent concentration of patulin was maintained at 0.25 mmol/L for 192 h. The total amount of patulin produced by the continuuous run was 35% greater than that obtained in a semibatch run. The pathway efficiency was 0.35 for 192 h indicating the biosynthetic pathway was operating at a high catalytic efficienc

ISSN:0008-4034    

DOI:10.1002/cjce.5450620118

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThe longevity of the enzyme system for the production of the antibiotic patulin by immobilizedPenicillium urticaecells was studied in a three phase fluidized bed reactor. Calculation of the global rate of patulin production indicated that, if the cells were not allowed to grow, the production of patulin gradually declined and stopped at 320 h. Intermittent pulse additions of nutrients stimulated the slow growth of the cells and resulted in an extended production time of 525 h. This long term production was the result of the formation of new cells rather than the maintenance of the original ones.

ISSN:0008-4034    

DOI:10.1002/cjce.5450620119

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractAn unsteady‐state method for determination of the thermal diffusivity of a porous sphere, based on direct contact condensation of steam, was developed. A modified formula relating thermal diffusivity to porosity was proposed from theoretical considerations. Experimental measurements on known solids showed good agreement with literature values. Unknown thermal diffusivities of some metallic oxides (in powder form) were determined at 60°C, with the following results:Cr2O3: α = 1.23 (106) m2/s: CuO: α = 2.63 (106) m2/s: Fe2O3: α = 1.02 (106) m2/s; V2O5: α = 1.14 (106

ISSN:0008-4034    

DOI:10.1002/cjce.5450620120

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractA new method was developed to measure the vapor pressure of sulfur dioxide above various liquid absorbents. It was applied to pure 1‐methyl‐2‐pyrrolidone and its aqueous solution at 50°C to 91°C for SO2loadings of 3.73 × 104kg/kg to 2.16 × 10−2kg/kg. A chemical model was developed. The heat of solution was calculated from the dependence of the vapor pressure on temperature and was 3.98 × 107J/kmol (exothermic) for pure 1‐methyl‐2‐pyrrolidone. The vapor pressures disagreed with the only previously published set of results but were confirmed by independent measurements with a

ISSN:0008-4034    

DOI:10.1002/cjce.5450620121

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY