(193d) High Temperature, Pressure Swing Adsorption Process for the Production of Ammonia
Pressure swing adsorption (PSA) technology enables the energy-efficient recovery of specific compounds from a gas under pressure. In this project, an ammonia production process that incorporates PSA for the recovery of ammonia from the product gas and purification of the process reactants, nitrogen (from air) and hydrogen (from steam methane reforming, SMR) is being developed. The process converts methane, air, and water to ammonia, with carbon dioxide and a small amount of argon as byproducts. Current ammonia processes react air and syngas (gas mixture of carbon dioxide and hydrogen) to form ammonia, which is recovered via energy-intensive refrigeration and condensation. The new approach will increase ammonia yield and reduce natural gas feedstock and fuel consumption. The improved ammonia process will find application in the U.S. chemical industry, which produced 23.7 billion pounds of ammonia in 2004. Ammonia is also used at power plants in selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) systems, to reduce NOx emissions. The new process is scaleable and enables on-demand ammonia production for such applications. This presentation will provide an overview of the proposed ammonia production flow sheet and give an update on the status of the project with respect to PSA process design for ammonia purification.