Potential of tri-reforming process and membrane technology for improving ammonia production and CO₂ reduction

In this work, a tri-reforming process was coupled with a membrane separation unit to enhance efficiency of ammonia (NH₃) synthesis process in terms of CO₂ emission, NH₃ production, and NO_x emission. Primary and secondary reformers were replaced by a tri-reforming process, while a Perovskite membrane was applied to separate nitrogen (N₂) from oxygen (O₂). A conventional NH₃ synthesis process and the proposed process were simulated by Aspen-Hysys and compared in order to investigate the performance of the proposed sterategy. The simulation results indicated that when temperature increased and pressure decreased, conversion of hydrocarbons and H₂/CO ratio were improved from 1.73 to 2.54, which resulted in an increase in NH₃ production by 27 %, and a decrease in CO₂ emission rate from 1192 kg/h to approximately 1 kg/h. The proposed sterategy was optimized in terms of different parameters e.g., temperature and pressure. Optimum reaction pressure and temperature were determined to be between 1 and 10 bar and 500-800 °C, respectively. The results of the study revealed that the proposed strategy not only removed amine and methanol sweeteners which reduce the operational costs of the process, but also decreased the NO_x content from 8220 ppm to almost 10 ppm.