Thermodynamic analysis of autothermal steam‐reforming of methane for ammonia production

Abstract

Autothermal reforming of methane is one of the most widely reported techniques for syngas production. This thermodynamic analysis discusses two aspects of autothermal reforming: first, to obtain hydrogen to nitrogen in the ratio 3:1, which is the most suitable feed ratio for ammonia production in the Haber–Bosch process, and then to find out the thermoneutral point of the process. Throughout the study, all simulations are carried out at 1 bar pressure and within the temperature range 500–1000°C. Conditions with more than 99% methane conversion and 0.1% coke deposition are considered. Other parameters taken into account for optimization are OMR (oxygen to methane ratio) in range 0.4–0.6, SMR (steam to methane ratio) in range 1.5–3.5 and oxygen enrichment in air from 25% to 40%. This study briefly discusses the water gas shift (WGS) reaction for CO removal and its conversion to H2. The best thermoneutral point for the reformer was found to be at OMR = 0.59845, SMR = 2.105, with an oxygen enrichment level of 39.4%.