METHOD OF OXIDATIVE DEHYDROGENATION OF LOW-EMISSION FOR BUTADIENE OBTAINING Russian patent published in 2017 - IPC C07C5/48 C07C11/167 

FIELD: chemistry.

SUBSTANCE: one of the process variants includes the steps of: evaporating and superheating said butene-enriched hydrocarbon feedstock at a temperature of at least 205°C (400°F), mixing said butene-rich hydrocarbon feed with superheated steam and with oxygen-rich gas to form a reactor feed stream; Oxidative dehydrogenation of said reactor feed stream with a ferritic catalyst to form a butadiene-rich product stream in which: the butadiene-rich product stream is used to provide heat to the reactor feed stream by combining indirect heat exchange with the removal of significant heat from the butadiene-rich product stream and thermal oxidation of undesired hydrocarbon products, Separated from the butadiene-rich product stream, mentioned stream of the butadiene-rich product at a temperature of at least about 510°C (950°F) passes first through a reactor superheater in which a mixture of water vapor and butene-rich hydrocarbons entering the reactor overheats by indirect heat exchange with said stream of butadiene-rich product at a temperature of at least 345°C (650°F), the butadiene-rich product stream emerging from said reactor feed superheater is passed through a steam generator in which water evaporates and an indirect heat exchange with said stream of butadiene-rich product, the butadiene-rich product stream is then passed through a C4 absorber in which C4 compounds including butadiene are absorbed in a compatible absorption oil, the absorption oil is passed through a degassing column in which non-C4 volatiles are removed, A C4 stripping unit in which the C4 compounds, including butadiene, are stripped/stripped from said absorption oil under reduced pressure, wherein the dispersed volatile lower organic The other compounds are stripped from the aqueous liquid distilled from the butadiene-rich product stream, and the resulting aqueous stream is recycled to the steam generator so that, in the established operation, the energy content of mentioned buten-enriched feed for the oxidative dehydrogenation reactor delivers at least 40% of the energy required for: evaporating and superheating said buten-enriched hydrocarbon feed, and evaporating and superheating the water used for Feeding said superheated steam to mentioned reactor feed stream.

EFFECT: significant heat is used at high temperature in order to supply and overheating at somewhat lower temperatures in order to supply evaporation in successive locations in the process.

20 cl, 6 dwg, 3 tbl