Integrated process for preparing a carboxylic acid from an alkane

摘要

The present invention relates to an integrated process for producing unsaturated carboxylic acids from the corresponding C2-C4 alkane. The process begins with integrated catalytic reactions comprising endothermic soft oxidant conversion (SOC) and exothermic selective hydrogen combustion (SHC) which cumulatively convert a C2-C4 alkane to its corresponding C2-C4 alkene in a product stream substantially free of hydrogen. Heat from the exothermic selective hydrogen combustion reaction zone is recovered and recycled back upstream to the endothermic soft oxidant conversion reaction zone. The hydrogen-free alkene products of the thermally integrated SOC/SHC reactions are then provided to a catalytic vapor phase partial oxidation process for conversion of the alkene to the corresponding unsaturated carboxylic acid or nitrile. Unreacted alkene and carbon dioxide are recovered from the oxidation product stream and recycled back to the thermally integrated soft oxidant conversion reactions.