Development of a new environmentally benign cascaded ammonia fuel generating system

Abstract

Ammonia synthesis is recognized as a cornerstone of the chemical industry, yet it remains an energy-intensive process. As the demand for more efficient and sustainable production methods grows, this study designs an environmentally benign cascaded ammonia synthesis system, exploring three distinct configurations: single-stage, double-stage, and triple-stage cascaded systems. By implementing multiple reactors in series integrated with absorbent-enhanced separation (AES) technique, an effective solution is developed to eliminate the energy costs associated with gas recycling and minimize the number of recycle loops. A simplified AES model is developed using magnesium chloride (MgCl₂) absorbent and assuming 90 % recovery factor that selectively binds to ammonia while ensuring continuous separation with minimal energy loss, preserving the pressure and temperature of the feed to the subsequent reactor. Through process simulations conducted with the Aspen Plus V11, our findings reveal that multi-stage configurations outperform single-stage synthesis, achieving higher energy efficiency and ammonia yield. The production capacity of single, double, and triple stage design comes out to be 1890 kg/day, 2640 kg/day, and 2800 kg/day. Additionally, the study incorporates sensitivity analyses, which elucidate the impact of various operational parameters on performance. The findings offer valuable insights for optimizing industrial-scale ammonia production while minimizing energy consumption and environmental impact.