Psa process with reaction for reversible reactions

Abstract

A process is disclosed for the production of methanol from a synthesis gas stream comprising hydrogen and carbon dioxide in which an equilibrium reaction to methanol is achieved by conducting the reaction and the product separation in a pressure swing adsorption and reaction zone containing a uniformly distributed adsorbent for the selective adsorption of methanol and a catalyst for the equilibrium conversion of the synthesis gas to methanol. More specifically, the process achieves the production of methanol by the reaction of the hydrogen and the carbon oxide with the simultaneous adsorption of the product at the same temperature and pressure. The passing of the synthesis stream to the bed is terminated and the bed is purged and depressurized to desorb the methanol product. In one embodiment, the bed is cocurrently purged with at least a portion of an effluent stream prior to depressurizing the bed. In further embodiments, the pressure swing adsorption and reaction zone is employed in a methanol synthesis loop both with and without a secondary reforming step to provide a lean synthesis gas with a stoichiometric ratio of carbon to hydrogen. The use of the pressure swing adsorption and reaction zone results in a higher conversion of the synthesis gas to methanol and significantly reduces the capital and operation costs in the production of methanol by reducing compressor requirements.