Novel technology for coal mine methane utilization, process simulation and catalyst development

Abstract

AbstractGlobal methane emission from coal mines were estimated to be approximately 584 MMTCO2 E in 2010, which is a huge waste of energy resources and is an important source of greenhouse gas (GHG) emission. Coal mine methane (CMM) whose methane content is 30∼60% with the rest of air is difficult to use directly. A novel process for CMM utilization is developed in this work. CMM is used as the feedstock for urea synthesis. This process does not require separation or further purification of CMM, but converts the methane into hydrogen through the oxygen in it and by adding steam. The reformate can be further processed into a mixture of hydrogen and nitrogen with a molar ratio of H2:N2 = 3:1, which can then be used for urea synthesis. This process has been analyzed by Aspen Plus. It is found that the optimal CMM composition for urea production is 42% of methane in the air system, with water added at an H2O/CH4 ratio of 3.26. Reforming catalyst has been developed and tested in a simulated industrial reactor, with CMM simulated by mixing civil use grade methane and air. The reformate composition was analyzed by gas chromatography (GC) and the results match the simulation very well. A 10‐day test showed high stability of the catalyst. In addition, the reforming catalyst after 10 days of operation was characterized using XRD and Laser Raman. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.