Process Modeling of an Advanced NH₃ Abatement and Recycling Technology in the Ammonia-Based CO₂ Capture Process

Abstract

An advanced NH₃ abatement and recycling process that makes great use of the waste heat in flue gas was proposed to solve the problems of ammonia slip, NH₃ makeup, and flue gas cooling in the ammonia-based CO₂ capture process. The rigorous rate-based model, RateFrac in Aspen Plus, was thermodynamically and kinetically validated by experimental data from open literature and CSIRO pilot trials at Munmorah Power Station, Australia, respectively. After a thorough sensitivity analysis and process improvement, the NH₃ recycling efficiency reached as high as 99.87%, and the NH₃ exhaust concentration was only 15.4 ppmv. Most importantly, the energy consumption of the NH₃ abatement and recycling system was only 59.34 kJ/kg CO₂ of electricity. The evaluation of mass balance and temperature steady shows that this NH₃ recovery process was technically effective and feasible. This process therefore is a promising prospect toward industrial application