F2. Reaction kinetics of the shell air-solutizer sweetening process

✍ Scribed by H. Groothuis

• Book ID: 103005819
• Publisher: Elsevier Science
• Year: 1961
• Tongue: English
• Weight: 552 KB
• Volume: 14
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(61)85072-0

✦ Synopsis

The Shell air-solutixer sweetening process converts the malodorous mercaptans present in certain gasoline fractions into less pungent disulphides. This is accomplished by contacung the gasoline, in which oxygen has been dissolved, with an aqueous solution of potassium hydroxide and certain organic compounds. The latter may be fatty or cresylic acids, which are added to increase the solubility of the mercaptans, and are therefore known as "solutixers".

During the contacting, usually carried out in a continuously operated stirred tank reactor, mercaptans and oxygen are transferred to the alkaline solution, where the conversion into disulphides occurs.

This paper deals with results of experiments and calculations concerned with the influence of the main process variables on the rate of mercaptan conversion. The reaction between oxygen and mercaptans was found to be first order in the oxygen concentration and of the order O-25 in the mercaptan concentration. The influence of the rate of mass transfer on the over-all rate of conversion was also investigated.

It is concluded from the data that even at a stirring energy as high as 5 h.p./ms the over-all rate of conversion is still limited by the rate of oxygen transfer.