Production of acrolein or acrylic acid from propane, involves partial gas-phase dehydrogenation, removal of hydrogen and partial gas-phase oxidation of propene with nitrogen as diluent, and recycling of unreacted propane

摘要

Molecular nitrogen is used as a diluent gas in the partial oxidation stage of a 3-stage method for the production of acrolein and acrylic acid from propane by: (A) partial gas-phase dehydrogenation; (B) removal of hydrogen and partial gas-phase oxidation of propene; and (C) separation of product and recycling of unreacted propane to stage (A). Acrolein and acrylic acid are produced from propane by: (A) partial gas-phase dehydrogenation of propane in presence of a heterogeneous catalyst to form a mixture (A) containing molecular hydrogen, propene and unreacted propane; (B) removing at least some of the hydrogen from the components other than propane and propene to give a mixture (A'), feeding (A') into oxidation reactor(s) and subjecting the propylene to selective, gas-phase partial oxidation in presence of heterogeneous catalyst to give a gas mixture (B) containing acrolein and acrylic acid; and (C) separating the required product and recycling unreacted propane (at least) to stage (A). In this process, molecular nitrogen is used as diluent gas in the partial oxidation stage (B).