01957nas a2200169   4500008004100000022001400041245011800055210006900173260007100242300001400313490000700327520126300334100001501597700002201612700002101634856013201655       2015                        eng d  a1083-616000aContinuous-flow nitration of o-xylene: effect of nitrating agent and feasibility of tubular reactors for scale-up0 aContinuousflow nitration of oxylene effect of nitrating agent an  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a1138-11470 v193 a<p>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.</p>1 aSharma, Y.1 aJoshi, Ramesh, A.1 aKulkarni, A., A.  uhttps://library.ncl.res.in/content/continuous-flow-nitration-o-xylene-effect-nitrating-agent-and-feasibility-tubular-reactors-0