Patent ID: 9650316
Date: 2017-05-16
CPC Classifications: B01J,C07C,Y02P

Claim:
1. An improved low emissions method of converting a hydrocarbonaceous butene rich feed into butadiene, wherein the improvement comprises the steps of: vaporizing said hydrocarbonaceous butene rich feed, mixing the vaporized hydrocarbonaceous butene rich feed with steam to produce a combined stream, and superheating the combined stream to provide a reactor feed stream; oxidatively dehydrogenating said reactor feed stream with an oxygen rich gas over a ferritic catalyst, thereby forming a butadiene enriched product stream, wherein the temperature of the butadiene enriched product stream is at least about 510° C. (950° F.); passing the butadiene enriched product stream at a temperature of at least about 510° C. (950° F.) first through a reactor feed superheater in which the reactor feed stream is superheated by indirect heat exchange with said butadiene enriched product stream to at least 345° C. (650° F.); passing the butadiene enriched product stream exiting said reactor feed superheater through a steam generator in which water is vaporized by indirect heat exchange with said butadiene enriched product stream exiting said reactor feed superheater to provide vaporized and/or superheated steam; passing the butadiene enriched product stream exiting said steam generator through a C4 absorber, wherein C4 compounds including butadiene are absorbed in an absorption oil, passing the absorption oil through: (i) a degasser tower in which non-C4 volatiles are removed and (ii) a C4 stripper in which C4 compounds including butadiene are desorbed/stripped from said absorption oil under reduced pressure, passing the non-C4 volatiles to a thermal oxidizer to generate steam, wherein the steam from the thermal oxidizer is used to supply heat to the reactor feed stream, stripping aqueous liquid from the butadiene enriched product stream to provide an aqueous stream containing dispersed volatile organics, stripping the dispersed volatile organics from the aqueous stream to produce a resultant aqueous stream, wherein the resultant aqueous stream is recycled to the steam generator; such that in steady operation, the energy content of said butadiene enriched product stream supplies at least 40% of the energy needed for: vaporizing and superheating said hydrocarbonaceous butene rich feed; and vaporizing and superheating the water used to supply superheated steam in said reactor feed stream.