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Title: Studies in the higher coal tar bases
Author: Pryde, Alan William
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1951
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The work to be described in this thesis takes the form of an investigation of the nitrogenous bases which can be extracted by sulphuric acid from the Naphthalene Oil and the Benzol Absorbing Oil fractions of coal tar, after the tar oils have been freed from phenols by extraction with caustic soda. The chief objects of the investigation were :- (1) To obtain a weight/temperature of distillation balance for both fractions of bases, thus showing the relative abundances of the more common fractions, and possibly indicating where any previously unidentified bases were liable to occur. (2) To make a closer study of the fractions boiling between 180° and 235 °, and over 265 °C /760mm.Hg, as these two fractions have not been exhaustively studied in the past, and, where possible, to isolate and identify pure bases. The nitrogenous bases which can be extracted by sulphuric acid from coal tar or coal tar oils consist mainly of pyridine, quinoline, isoquinoline, and their homologues, together with small quantities of pyrrole, aniline, toluidines, xylidines, acridine and naphthylamines. According to present industrial practice the only bases which are extensively utilised are pyridine and its lower homologues, the commercially available products being :- Pure Pyridine - This is obtained by a close fractionation of the lower tar bases and is used as an intermediate in the production of "sulpha" drugs (sulphapyridine), dyestuffs, vulcanisation accelerators and waterproofing compounds, and as a solvent and catalyst. "90 -140° or 90 -160° Bases" - These are obtained by crude fractionation of the lower tar bases and are used as denaturants, solvents, level- lers in leather dyeing, insecticides, and also in the production of pattern effects on cotton and rayon, and in lubricating oil refining. "90 -180° Bases" - These are obtained by crude fractionation of tar bases and are used as solvents, in anthracene purification, and as restrainers in metal pickling baths. In addition to these main industrial products the following are produced in smaller quantities :- Picolines - These have been produced in small quantities from time to time, but recently, owing to the great demand for nicotinic acid as an accessory dietary factor, an interest has been aroused in ß- pieoline, and considerable quantities have been produced for oxidation to nicotinic acid. I,utidines & Collidines - These have only been produced in semi-commercial and experimental quantities. It is difficult to ascertain the sources of the above products owing to the differences in works practice throughout the country, especially with respect to the temperature ranges of the oil cuts taken, but it would appear that they are produced for the most part from the lower boiling tar oils, and according to present works practice the bases are seldom removed from the Naphthalene Oil and Benzol Absorbing Oil fractions. The total United Kingdom production of "pyridine bases" amounted to 166,000 gallons in 1948 and to 167,000 gallons in 1949 (Nin. of Fuel & Power), and there are indications that more could be used if it were available. If this is the case, it is possible that the Naphthalene Oil fraction rn1 ht provide a useful auxiliary source. Very little work has been carried out on the utilisation of the tar bases boiling above 180 °C, such as are obtained from the Benzol Absorbing Oil fraction, although quinoline and isoquinoline have been isolated in semi -commercial and experimental quantities, and during the recent war the xylidines were separated for use as aviation fuel additives. It was considered, therefore, that some quantitative estimate of the constitution of the Benzol Absorbing oil base fraction would be of considerable value.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available