Enhancing the Acetylene Yield from Methane by Decoupling Oxidation and Pyrolysis Reactions: A Comparison with the Partial Oxidation Process

Abstract

The partial oxidation (POX) of methane is one of the most important processes to produce acetylene and syngas. The reaction pathway analysis using a detailed chemical mechanism (modified GRI 3.0) showed that the exothermal oxidation and endothermic pyrolysis reactions were highly coupled in the original POX process, which limited the yield of acetylene. A new process that physically separated the heat supply and pyrolysis reactions was proposed to increase the acetylene yield. The maximum yield of acetylene was enhanced from 33% to 52% in the theoretical calculations assuming inert and instantaneous mixing. A jet-in-cross-flow (JICF) reactor was designed to realize this new process. The computational fluid dynamics (CFD) method coupled with the modified GRI 3.0 was applied to simulate the complex interaction between turbulent mixing and reactions. The results showed that a high acetylene yield of 41% could be obtained in the JICF reactor. The optimization of the reactor indicated that the optimum number o...