Experimental investigation of using combined CH4/CO2 replacement and thermal stimulation methods for methane production from gas hydrate in the presence of SiO2 and ZnO nanoparticles

Abstract

A combination of thermal stimulation and CH4/CO2 replacement methods in the presence of nanoparticles was employed to enhance CH4 recovery and CO2 storage for a previously formed CH4 hydrate in a reactor. To this end, first, the effects of different CO2 injection pressures and CO2 hydrate formation temperatures were examined on the replacement process, and the optimum condition was obtained among the studied P-T conditions. In the second stage, silica and zinc oxide nanoparticles were added to the system to explore the influence of the nanomaterials on CH4 recovery and CO2 storage under the optimum conditions. The results indicated that the optimum methane recovery condition was 45 bar and 8 °C. Further, the efficiency of the combined method was enhanced significantly in the presence of nanoparticles. According to the results, the methane recoveries of 37.7% and 51.9% plus the CO2 storages of 54.6% and 68.4% were obtained in the presence of silica and zinc oxide nanoparticles, respectively. This study could be helpful to introduce a new approach for enhancing CH4 recovery from hydrate resources.