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

Abstract

Summary 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%.

Autothermal Reforming of Methane: A Thermodynamic Study on the Use of Air and Pure Oxygen as Oxidizing Agents in Isothermal and Adiabatic Systems

“…Other thermochemical routes can be used for this purpose, such as partial oxidation (PO) and autothermal reform (ATR). Among the cited alternatives, the autothermal reform of methane, which is of great importance for many applications related to chemical conversion for energy generation, is mainly used in large conversion units [7]. This reaction variant joins steam reforming and oxidative reforming reactions, emerging as a very promising alternative.…”

“…The costs for each technology used for hydrogen production vary in relation to efficiency, scale of production and implementation of carbon capture and storage (CCS) technologies [9], as shown in Table 1. CO 2 capture is incorporated, ATR has benefits since the most efficient separation process for this case manages to recover carbon dioxide at 3 atm, reducing the costs associated with compression to achieve pipeline transport pressures [7].…”

Numerical analysis of steam methane reforming over a novel multi‐concentric rings Ni/ Al 2 O 3 catalyst pattern

“…Therefore, a huge amount of research has been devoted to this technique. However, the SMR process requires a sustained heat supply to operate 30 ; hence, the combination of the SMR with an exothermic reaction in the autothermal reforming (ATR) process is an interesting way to provide the process with the required heat 26,31‐34 . This can also facilitate the decentralization of the SMR reaction and methane combustion stages of the hydrogen production process, thus leading to less fuel consumption 35‐38 .…”