摘要:

AbstractNew vapour–liquid equilibrium data have been obtained for the systems nitric acid–water and nitric acid–sulphuric acid–water and have been applied to the design of a column for the concentration of nitric acid by extractive distillation with sulphuric acid. The new data require an increase in the number of theoretical plates, and thus explain in part the present use of larger quantities of sulphuric acid than should be necessary in a column designed according to previously publish

ISSN:0021-8871    

DOI:10.1002/jctb.5010070402

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractThe modes of condensation of steam on a cooled metal surface are discussed, and an apparatus for studying them is described. With this the effect of a number of promoters of dropwise condensation has been studied. Conclusions are drawn concerning the relation between the activity and chemical constitution of promoters. Active promoters have in the molecule an unhindered hydrocarbon chain which confers water‐repellency on the compound and an ‘anchoring’ group which is usually a divalent sulphur

ISSN:0021-8871    

DOI:10.1002/jctb.5010070403

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractAt temperatures in the range 320–450° cresols undergo rapid disproportionation and isomerization over silica–alumina, silica–zirconia–beryllia and other cracking catalysts. It is necessary to add a small amount of steam to the cresol vapour in order to reduce losses of phenols as catalyst deposit and as dehydroxylated material. Conversion to phenol and xylenols is limited, by approach to equilibrium, to values around 20%. When conditions are chosen such that conversion is low, the disproportionation ofp‐cresol on silica–zirconia–beryllia can be shown to be of zero order. These catalysts are poisoned for all the reactions by sodium ion and by small amounts of aromatic bases, indicating that the reactions, like those of hydrocarbons under similar conditions, take place on acid groups i

ISSN:0021-8871    

DOI:10.1002/jctb.5010070404

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractIn the reactions of cresols and xylenols over silica–alumina at 380°, certain isomers predominate or tend to be concentrated in the products, whether they are formed by isomerization or disproportionation, and whatever the orientation of the starting material. These preferred products arem‐cresol, 2 : 4‐ + 2 : 5‐xylenols, and 2 : 3 : 5‐trimethylphenol; the last named can be isolated with particular ease. At 380° ethylphenol loses an ethyl group to about an equal extent by disproportionation and by cracking, and is partially isomerized. Alkylphenols react with benzene over cracking catalysts, with a transfer of alkyl groups; the normal disproportionation of the alkylphenol is then largely suppressed. The equilibrium between phenol, cresols and xylenols has been approached from both sides, setting limits to the value of the equilibrium constant of the disproportionation of cresols and giving a most probable value for Kpof about 0·5 (it being assumed that the cresols and xylenols are each sets of isomers in equilibrium). The non‐phenolic material formed from phenols in small amount as a byproduct consists of a complex mixture of substances including alkylbenzenes, diaryl ethers, xanthene derivatives,

ISSN:0021-8871    

DOI:10.1002/jctb.5010070405

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractThe flow properties of polystyrene and polyvinyl chloride are measured at high pressure and high rates of shear in the temperature range 130–220°. An injection machine is provided with a capillary tube fitted in the extrusion head and the pressure applied measured by means of a steel diaphragm.The flow behaviour of the polymers is shown to be non‐Newtonian and very dependent on the pressure applied, the dependence decreasing with increasing plasticizer content. The results may not be applied directly to extrusion or injection moulding processes without taking other factors into acc

ISSN:0021-8871    

DOI:10.1002/jctb.5010070406

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractAlthough the separation of (‐)‐sec.‐butylcarbinol from fusel oil has been reported previously, in view of the utility of this substance as a source of optically‐active material, details of the methods now used, both by distillation and by crystallization of the hydrogen phthalic ester, are described. The effect of temperature on the rotatory power at various wavelengths is recorded. The pure laevorotatory alcohol, α 546125−5·654°, now obtained suggests that previous samples

ISSN:0021-8871    

DOI:10.1002/jctb.5010070407

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010070408

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractSolutions of hydrogen cyanide were heated in the presence of ammonia, ammonia and carbon dioxide, and ammonia and hydrogen sulphide, to temperatures between 60° and 110°. At high pH, the hydrogen cyanide was hydrolysed completely to ammonium formate; in less alkaline solutions some ammonium formate was formed, the remaining hydrogen cyanide polymerizing. The apparent energy of activation was about 20 kcal. per mole. Experiments in sodium carbonate/sodium bicarbonate solutions gave reaction rates similar to those in ammoniacal solution

ISSN:0021-8871    

DOI:10.1002/jctb.5010070409

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010070401

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY