An innovative coupled process between methane dry reforming and carbon dioxide methanation by both mass and energy integration

Carbon dioxide (CO₂) conversion technology has been estimated as a potentially practical solution for global warming, although there are still some challenging issues such as high cost and big energy consumption. Methane dry reforming (MDR) and carbon dioxide methanation (CDM) are regarded as the two interesting and attractive processes among these technologies. In this study, a novel coupled process by combining MDR with CDM was firstly proposed and investigated in detail, in order to overcome the existing drawbacks of each single process. Not only can the coupled process save natural gas and hydrogen use by mass integration, but it also can economize on energy consumption by energy integration. The simulation results indicate that hydrogen and natural gas consumption can be reduced to varying degrees according to different requirements. Moreover, in this innovative-coupled MDR-CDM process, the exothermic CDM section can provide heat input to the endothermic MDR section, thus lowering energy consumption. Under a temperature combination of 500 ℃ (MDR)-600 ℃ (CDM), the energy consumption of this coupled process can be decreased by 39.0 % and 36.5 %, respectively, compared with the conventional independent MDR process at 900 ℃ and CDM process at 300 ℃, correspondingly.