Performance Assessment of Tri-Reforming of Methane

There is growing interest in hydrogen (H2) as an energy carrier and fuel. Since H2 is a secondary or intermediate energy carrier, it is mainly produced from primary fossil fuels. To overcome the challenges of traditional reforming methods (such as high energy demands and CO2 emissions), this study investigates an alternative method, called tri-reforming, which combines the steam reforming of methane (SRM) and dry reforming of methane (DRM) with partial oxidation of methane (POM) in the same reactor. The energy requirement for this method is low since POM is an exothermic process that supplies the thermal energy for the endothermic SRM and DRM processes. Furthermore, the method can also potentially produce the desired quality of syngas (high H2/CO ratio) with low susceptibility to coking and high catalyst stability. A process model of a methane tri-reforming reactor is developed in Aspen Plus by employing the conservation of mass, momentum, and energy. In this study, we investigate the effect of the H2O/CO2/O2 feed ratio together with CH4 as fuel and find their optimum value to produce blue hydrogen (through an optimized H2/CO ratio) at different temperature conditions. The results present the specific O2/CH4 ratios at different temperatures (125–925°C), which would support the CO2/H2O conversion and achieve lower CO2 emissions (molCO2e/molCH4) with lower heat demand for producing hydrogen than the corresponding SRM and DRM processes.