摘要:

AbstractThe purpose of this investigation was to study a method for estimating the influence of the mass transfer conditions in gas—liquid reactions studied by the gasometric method. Theoretically it is shown, that when a reaction is taking place in the slow reaction regime, the initial gas absorption rate is higher than later on in the reaction, since an accumulation of the gaseous reactant, dissolved in the liquid phase, must occur immediately after the contact between the gas and the liquid. This effect is typical for the slow reaction regime. The rate of the initial gas absorption can be used to calculate the degree of saturation of the liquid at any moment. Furthermore, the error in gasometric measurements due to changes in the rate of reaction is discussed and a formula is derived, which permits calculation of this error from the absorption curve. In the experimental part the use of this method is demonstrated on the liquid‐phase oxidation of benzaldehyde in acetic acid solut

ISSN:0375-9210    

DOI:10.1002/jctb.2720240102

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractAfter establishing that high yields (up to 80% w/w on carbon basis) of acetylene could be obtained by electron‐activated cracking of methane in anomalous glow‐discharges at reduced (∼ 60–100 torr) pressure, the laboratory tests were scaled up and a 201 spherical reactor was used. The effects of electrode geometry, gas flow rate and high power inputs on the yield and production rate of acetylene and on specific energy consumption were studied and conditions for the economic production of acetylene were established. The applicability of the “electro‐cracking” technique to the production of acetylene from propane has also been

ISSN:0375-9210    

DOI:10.1002/jctb.2720240103

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractA method which allows the rapid and accurate determination of specific surface area for materials from a single point on the nitrogen adsorption isotherm is described. The calculation is made from a single adsorption point which can lie almost anywhere on the isotherm. The method does not suffer from the theoretical errors involved when the single point BET method is used and so is found to give accurate values over a larger pressure range.

ISSN:0375-9210    

DOI:10.1002/jctb.2720240104

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractPotassium chlorate, which is used mainly in the manufacture of matches, was prepared by the electrolytic oxidation of potassium chloride in an 800 A cell using graphite substrate lead dioxide anode and stainless steel cathode. The cell was operated at an anode current density of 5 A/dm2, a temperature of 55 to 60 °C and a pH of 6.0 to 7.0. A current efficiency of 82 to 85% was obtained and an assay yield of 77% was realised for the recrystallised product. The cell voltage was 3.2 to 3.3 V with an energy consumption of 6.3 to 6.5 kWh (d.c.)/kg of potassium chlorate produced.The cell effluent, being clear and free from suspended impurities, could be processed further without filtration and pure potassium chlorate (>99%) was obtained by recrystallisation

ISSN:0375-9210    

DOI:10.1002/jctb.2720240105

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe formation of C6Cl6(bz), CCl4and C2Cl6by the sealed‐tube pyrolysis of chlorocarbons, has been confirmed. The chlorinolysis of C6Cl6(bz), C4Cl6(1,3 diene) and C2Cl4yields CCl

ISSN:0375-9210    

DOI:10.1002/jctb.2720240106

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractBromination of some aromatic compounds is carried out using bromine in tetrachloroethane medium in the presence of iodine as a halogen carrier. The compounds investigated here are classified into: (i) compounds which yield pentabromophenol, (ii) compounds which yield other polybromoderivatives, and (iii) those which do not react with the brominating agent.

ISSN:0375-9210    

DOI:10.1002/jctb.2720240107

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractAn experimental investigation has been made of the regeneration of phenol and caustic soda simultaneously by the electrolysis of aqueous sodium phenoxide in a cell using a cation exchange membrane as diaphragm. Current efficiencies close to 100% for both anodic and cathodic processes have been obtained for short periods of electrolysis but with prolonged operation considerable inefficiency arises due to adsorption and oxidation of phenol and loss of ion selectivity of the diaphragm. The presence of solid manganese dioxide in the electrolyte has been found to be useful in partially inhibiting the adsorption or oxidation of phenol at the anode.

ISSN:0375-9210    

DOI:10.1002/jctb.2720240108

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe non‐oxidative decomposition of heated sodium dithionite was shown by thermal and i.r. spectroscopic analyses to proceed by two routes depending on sample configuration. The previously postulated reaction\documentclass{article}\pagestyle{empty}\begin{document}$$ 2{\rm Na}_2 {\rm S}_2 {\rm O}_4 \to {\rm Na}_2 {\rm S}_2 {\rm O}_3 + {\rm Na}_2 {\rm SO}_3 + {\rm SO}_2 $$\end{document}predominated when the heaped substance was heated at 16 °C/min giving a sudden exotherm of 47 kJ mol−1at 205 °C. In other conditions, particularly when heated in thin layers, two exotherms were found. The major exotherm at 210 °C yielded 63 kJ mol−1the main products being thiosulphate, trithionate, sulphate and sulphite. A subsequent exotherm at 250 °C appeared to arise from phase changes in this material, coincident with the endothermic decomposition of sodium tr

ISSN:0375-9210    

DOI:10.1002/jctb.2720240109

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe method used to measure conductivity consisted of embedding resistance wire, around which thermocouple wire had been wound, in the wax. An electric current was passed through the wire and temperature rise was recorded as a function of time. The determination was repeated at various temperatures from 20 to 120 °C, i.e. in the solid and liquid states.The resulting conductivity‐temperature curve has an S shape, like the curves for specific volume and most other physical properties of substances that are crystalline in the solid state. Equations for reduced thermal conductivity were applied. For the solid state external degrees of freedom could be calculated and the partially crystalline nature was confirmed. Experimental and predicted values for reduced conductivity of molten wax differed somewhat, probably because of persisting order in the liquid state. There is a retrograde tendency in conductivity above the melting point. According to the literature measurements on alkanes are likely to be subject to errors due to convection unless extreme precautions are taken. This effect could cause the retrogressi

ISSN:0375-9210    

DOI:10.1002/jctb.2720240110

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe simultaneous production of α‐amylase, β‐glucanase and proteolytic enzymes byBacillus subtilishas been studied. The effect of culturing conditions on the simultaneous production of these enzymes has also been investigated. Two known strains were used as standards, the other strains having been isolated and selected in this laboratory for their high enzyme production properties. Of the newly isolated strains three had better enzyme production properties than the standard strains. Selective inhibition was employed to separate total proteolytic activity into two fractions. The strainK160, which was the best strain for enzyme production, produced very few heat stable (100 °C) spores in the culturing conditions used. Enzyme production was correlated with sporulation, which reached its maximum value after about 30 h cultivation. α‐Amylase reached its maximum activity at the same time as sporulation, as did alkaline protease. The maximum for neutral protease activity, however, occurred at an earlier stage, whilst β‐glucanase activity usually continued to increase till the end of the cultivation (48 h). The optimum temperature, agitation and aeration values were determined for the production of enzymes in fermentor cultivation. β‐Glucanase showed remarkably little susceptibility to altered culturing conditions, as did alkaline protease. Sporulation level was always low (5 to 10%) in those cultivations in which enzyme activities reached their

ISSN:0375-9210    

DOI:10.1002/jctb.2720240111

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY