摘要:

AbstractMass transfer coefficients have been determined for transfer into a highly viscous phase in a stirred tank involving high Schmidt numbers. The results have been used to compute mass transfer coefficients in the extraction of free fatty acids from oils using alcohol and show good agreement with experimental results.

ISSN:0375-9210    

DOI:10.1002/jctb.5020230302

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe fluorination in gaseous phase of carbon tetrachloride has been investigated on aluminium fluoride with the aim of defining the mechanism of the reaction on this catalyst.The reactor and the operating conditions, were chosen in such a way as to isolate the effects of diffusion analysing the single reaction steps.While for the process in liquid phase the kinetics appears to be controlled by the formation of activated complexes between carbon tetrachloride and the catalytic support, the selective adsorption of HF on the catalyst is more probably the controlling step when the reaction is carried out in gaseous phase.

ISSN:0375-9210    

DOI:10.1002/jctb.5020230303

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe structure of three series of microcrystalline waxes has been studied using X‐ray diffraction and i.r. techniques. Their relative methylene/methyl group ratios as well as solid state parameters like size and shape of the unit cell, crystallite size and total crystalline fraction have been calculated. An attempt has been made to correlate these structural data with gross physical properties like oil content and needle penetration point. These correlations are found to hold good within any given series but varies from one series to anothe

ISSN:0375-9210    

DOI:10.1002/jctb.5020230304

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractGlycerolysis of the methyl esters of oleic and stearic acid has been investigated in presence and absence of zeolite 4A. By removing the methanol produced this zeolite improved the yields of glyceride substantially. Other factors studied which influenced the yields were temperature, reactant concentrations and proportions and catalyst.

ISSN:0375-9210    

DOI:10.1002/jctb.5020230305

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe analysis of nitric oxide, the principal nitrogen oxide in raw exhaust gas, is described by two different techniques. Concordance of analytical determinations using the Saltzman colorimetric solution method with the gas phase chemiluminescence method is demonstrated.By dilution of exhaust gas from an internal combustion engine with nitrogen it is shown that gas samples can be stored for periods of at least 30 min without significant change in sample composition with respect to nitric oxide. This procedure enables reliable estimations of nitric oxide in exhaust gas contained in a sealed transportable vessel to be performed at sites remote from the sample point, without introducing errors due to loss of nitric oxide by chemical reaction in the time between sampling and analysis.

ISSN:0375-9210    

DOI:10.1002/jctb.5020230306

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

ISSN:0375-9210    

DOI:10.1002/jctb.5020230307

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe chemistry of the solution of welding fluxes in Li2O‐B2O3melts prior to analysis has been examined using chemical thermodynamics. A chemical model describing these melts is proposed, and using it, the particular abilities of two components of the fluxes, SiO2and Al2O3, in facilitating loss of fluorine from the solutions, are describe

ISSN:0375-9210    

DOI:10.1002/jctb.5020230308

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractCrystalline α‐zirconium phosphate has been prepared by four methods. The products have been characterised by chemical and thermal analysis, X‐ray and infrared spectroscopy, surface area, porosity and particle size determinations and electron microscopy. A method is recommended for the preparation of crystalline α‐zirconium ph

ISSN:0375-9210    

DOI:10.1002/jctb.5020230309

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractAspects of fermentation dynamics are discussed, especially from the point of view of process development. Initial examples are from laboratory work in continuous culture. After this the economic and dynamic aspects of protein production by continuous culture are reviewed. In the last part the optimisation of the pencillin fermentation is considered, based on the use of a model which predicts yields, with a fermentation limited by the rate of oxygen transfer to the culture, when penicillin production falls at low growth‐rates. A process involving a sugar feed is considered, the main factors being the concentration of nitrogen in the medium, which governs initial cell production, and sugar feed rate which maintains further growth. The model predicts high yields over a wide variety of conditions. This indicates the difficulty of a pilot‐plant optimisation programme, when the maximum yield point is not critical. Other factors in the fermentation are also discus

ISSN:0375-9210    

DOI:10.1002/jctb.5020230310

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractWet air oxidation (the patented Zimmermann process) destroys organic matter in sewage sludge by bringing a sludge‐air mixture to elevated temperature (260 to 370 °C) and pressure (12.4 MPa) and holding it for a reaction time of 35 to 55 min. These conditions result in 70 to 80% COD removal with carbon dioxide, water, short chain aliphatic acids, and ash as products. Energy recovery provisions enable the process to be self‐contained at sludge concentrations of 4.5 to 5% which are difficult to obtain. An additive to the process which would enable successful oxidation to proceed with less concentrated sludge, at lower pressures and shorter times would be useful.Hydrogen peroxide in combination with several metal salts was tested as an additive. Hydrogen peroxide plus dichromate was found to destroy 70% of the COD of a glucose solution (500 mg/1 COD) at 150 °C and 5.2 MPa in 15 min. The ratio of the equivalents of the substances glucose: hydrogen peroxide: dichromate stood as 13 : 6.5 : 1.The amount of COD destroyed exceeded the oxidative equivalents of peroxide and dichromate present; hence it was concluded that molecular oxygen was incorporated in the rea

ISSN:0375-9210    

DOI:10.1002/jctb.5020230311

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY