Cost-effective clean ammonia production using membrane-assisted autothermal reforming

Abstract

Ammonia is a widely produced industrial chemical, primarily for use in the fertilizer industry. Recently, interest has also grown in ammonia as a carbon-free energy carrier because it is easier to store and transport than hydrogen. However, ammonia is primarily produced from natural gas with a considerable carbon footprint if the produced CO2 is not captured and stored. This work therefore presents a new ammonia production method based on membrane-assisted autothermal reforming (MA-ATR) for hydrogen production from natural gas with integrated CO2 capture. The MA-ATR reactor offers great process intensification benefits, leading to considerable efficiency gains as well as a simpler and cheaper plant. In the base case, MA-ATR achieves 10.7% greater efficiency, 14.9% lower NH3 production costs and 16.5%-points greater CO2 avoidance than a conventional ammonia plant where captured CO2 is compressed for transport and storage. This economic advantage of MA-ATR increases with higher natural gas prices, lower electricity prices, lower membrane costs and higher CO2 prices. All elements of the proposed plant are mature technologies aside from the membranes and the oxygen carrier material. Further development and demonstration of these two elements is therefore recommended to realize the promising techno-economic performance reported in this study.