摘要:

AbstractSolubility data expressed as mole ratio,xRH(moles of RH per mole of liquidS) have been measured for propane andn‐butane in a number of type‐representative organic liquids,S, at different temperatures,t°C, and pressures,pRH≤ 760 mm. These data, and those for methane, ethane and radon, afford support in the development of the essential pattern of data for all gases,A, and all liquids,S.This pattern indicates that the first factor determining the solubility of any gas,A, in any liquid,S, is its tendency to condense to a liquid at the operational temperature,t°C (e.g. 0 °C to 25 °C), shown by its vapour pressurep°Aover liquidA(or its equivalent for a gas above the critical temperature) att°C. Sincep°Aemerges from the b.p. ofAat 1 atm, and b.p. data are readily seen in text‐books, the b.p. may be taken as an initial index of the first factor. In theNA–pAdiagram for a given gasAand different liquids,S, at a fixedt°C,NAbeing the mole fraction ofA, the straight line joiningp°AwithpA= 0 is herein called the reference line, theR‐line, ofA; it is a real property ofA, and it represents the plot ofNA–pAfor a hypothetical liquid,S, having in effect an overall inter‐molecular structure equivalent to liquidA, in imagination,Aitself. TheNA–pAplot for another liquid,S, involves a second and a third factor, the second being the intermolecular structure ofS, in a dynamic sense, and the third, theinevitableinteraction ofAwithS.These factors are deemed to emerge from changes in electron density, designated for the present as acid‐base functions. The spread ofxRHvalues is indicated byxPrH= 0.322,xBuH= 5.25, for di‐n‐octyl ether;xPrH= about 0.000042,xBuH= about 0.000040, for

ISSN:0375-9210    

DOI:10.1002/jctb.5020230102

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA single multilayer curve was arrived at for the adsorption of nitrogen on silica gel. An empirical equation, fitted to the curve, proved to be suitable in the pore size analysis of 26 samples of silica gels; specific surface areas from 178 to 814 m2/g, mean pore radii of 12.6 up to 74.4 Å, and total pore volumes of 0.5126 to 0.8613 ml/g. Cumulative surface areas were evaluated by the procedures of BJH, Cranston and Inkley, and Roberts; the values obtained were generally in agreement with specific surface areas obtained by the BET equation,SBET, within ± 5%. The empirical equation is completely independent of the structural characteristics of the material. Comparison was made with data obtained by the use of the method of Mingle and Smith, for evaluating multilayer thickness, and which depends on both mean pore radius, and BET‐Cvalue, for each single solid. Good concordance appears between the cumulative surface areas, as well as the pore size distributions, calculated by employing either this lattert‐estimate or the empirical equ

ISSN:0375-9210    

DOI:10.1002/jctb.5020230103

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA detailed study has been made on the preparation and consequent heat treatment of various active nickel oxide—alumina catalysts. The techniques used in this study were surface area measurements, pore size analysis and density determinations. Three methods were employed for catalyst preparation, these being impregnation; co‐precipitation and bulk fusion of the metal nitrates. The results indicate that the catalyst prepared by co‐precipitation was the most suitable. By following surface area changes with temperature and time as variables two modes of sintering were noted, one occurring in the temperature range 1100 to 1164 K giving an activation energy of 98 kJ mol−1, and the other occurring in the temperature range 1182 to 1200 K giving an activation energy of 460 kJ mol−1. It is thought that the mechanism controlling the sintering in the first case is a direct result of surface diffusion, whilst that occurring in the second range is governed by volume diffusion. The decrease in the number of particles as a trend in sintering is calculated for the sample sintered at 1182 K using surface area and den

ISSN:0375-9210    

DOI:10.1002/jctb.5020230104

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe phosphonic cation exchanger in its free acid form is able to remove multivalent cations even from neutral and medium acidic solutions of salts of strong acids completely, and is regenerated by a stoichiometric amount of a regenerating agent. It is therefore possible to separate multivalent cations from univalent cations in a simple way by means of a phosphonic cation exchanger, followed by a weakly basic anion exchange resin. This results in a selective or partial de‐ionisation of solutions with an eventual recovery of multivalent cations using an economical regeneration dosage and with a minimum of wast

ISSN:0375-9210    

DOI:10.1002/jctb.5020230105

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractMagnesium oxalate dihydrate was used as a “generator” to produce active magnesium oxide by heating bothin vacuoand in presence of constant water vapour pressure. Results indicate that sintering is accelerated in presence of water vapour and probably takes place by a different mechanism than by heatingin vacuo.Sinteringin vacuois accompanied by widening of pores, whereas in presence of water vapour it is accompanied by narrowing of pores. The role played by water vapour in accelerating the sintering of magnesia is discussed and possible explanations are offered. Dual effects of water vapour might lead to the sintering acceleration of magnesia; chemisorption of OH groups which create cation vacancy on the surface leading to activated surface diffusion, and oxygen bridging between two adjacent/or opposite OH groups, particularly in narrow pores, leading to their narrow

ISSN:0375-9210    

DOI:10.1002/jctb.5020230106

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractAn empirical thermodynamic model for the NH3–H2OCO2system at equilibrium at urea synthesis conditions (140 ≤T≤ 200 °C, 50 ≤P≤ 250 atm, 2.4 ≤ NH3/CO2≤ 6, H2O/CO2≤ 0.5) is presented. This model can quantitatively or semi‐quantitatively describe a number of important phenomena in the urea synthesis, such as the bubble‐point and gas—liquid equilibrium conditions and the effect of excess ammonia and water on the conversion to urea in the liquid phase. The model also sheds light on the problem of the conversion to urea at high tem

ISSN:0375-9210    

DOI:10.1002/jctb.5020230107

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA thermal analysis study of the one‐stage decomposition of small (mg) quantities of carnallite, KCl. MgCl2, 6H2O → KCl + MgO + 5H2O ↑ + 2HCl ↓, showed that dehydration and hydrolysis require temperatures above 300 °C. Decomposition of greater amounts, and analysis of the products, showed that at 450 °C, 88 to 90% of the magnesium occurs as chloride‐free high‐purity periclase. At higher temperatures increasing amounts of chlorides remain in the periclase and are difficult to separate. Unglazed porcelain is a suitable material for the decompo

ISSN:0375-9210    

DOI:10.1002/jctb.5020230108

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

ISSN:0375-9210    

DOI:10.1002/jctb.5020230101

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY