Continuous-flow nitration of o-xylene: effect of nitrating agent and feasibility of tubular reactors for scale-up

TitleContinuous-flow nitration of o-xylene: effect of nitrating agent and feasibility of tubular reactors for scale-up
Publication TypeJournal Article
Year of Publication2015
AuthorsSharma, Y, Joshi, RA, Kulkarni, AA
JournalOrganic Process Research & Development
Volume19
Issue9
Pagination1138-1147
Date PublishedSEP
ISSN1083-6160
Abstract

Continuous-flow nitration of o-xylene has been studied with different nitrating agents over a wide range of conditions for different parameters such as temperature, residence time, and concentrations. A nitrating mixture comprising sulfuric acid and fuming nitric acid was seen to yield higher selectivity for the isomer 1,2-dimethyl-3-nitrobenzene over the isomer 1,2-dimethyl-4-nitrobenzene and also a non-negligible quantity of dinitro derivatives of o-xylene. With only fuming nitric acid as the nitrating agent, the reaction was selective for 1,2-dimethyl-4-nitrobenzene over 1,2-dimethyl-3-nitrobenzene. Impurities mainly come from nitration of mononitro derivatives, and this occurs more from nitration of the 3-nitro isomer because of its higher reactivity with nitric acid. An economic analysis of the continuous-flow reactor for the production of 1,2-dimethyl-4-nitrobenzene at 100 and 500 kg/h in a jacketed tubular reactor showed that numbering-up is a more economical approach for higher production capacity. A combination of large- and small-sized tubes depending upon the relative rates of heat generation during a reaction will achieve more profit and a shorter payback period than having the entire reactor made of a single tube size.

DOI10.1021/acs.oprd.5b00064
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)2.922
Divison category: 
Chemical Engineering & Process Development