1. Enhanced CH4 recovery and CO2 storage via thermal stimulation in the CH4/CO2 replacement of methane hydrate.
- Author
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Zhang, Lunxiang, Yang, Lei, Wang, Jiaqi, Zhao, Jiafei, Dong, Hongsheng, Yang, Mingjun, Liu, Yu, and Song, Yongchen
- Subjects
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CARBON dioxide adsorption , *METHANE hydrates , *DIFFUSION , *HYDRATES , *ENERGY storage , *ENERGY consumption - Abstract
The replacement of CH 4 by CO 2 in methane hydrates is a promising method for simultaneously achieving CO 2 storage and CH 4 recovery for global warming mitigation and energy production, respectively. However, gas replacement is restricted to the slow diffusion-limited transport of CO 2 caused by the formation of a mixed hydrate layer, and little attention has been paid to the storage of CO 2 . Therefore, this study proposed a combination of CH 4 /CO 2 replacement and thermal stimulation to enhance CH 4 recovery and CO 2 storage. The effects of the methane hydrate saturation level, replacement zone, and freezing point on the replacement were analyzed. The CH 4 replacement percentage and energy efficiency were obtained and compared using the replacement and combined methods. The results suggested that the combined method effectively improved CH 4 recovery, with the CH 4 replacement percentage exhibiting an upper limit of 64.63%. Moreover, In CH 4 /CO 2 replacement, the total number of moles of CO 2 stored is unequal to CH 4 recovered, because the replacement is sensitive to the free water in the pores of the hydrate sediments. In addition, the CO 2 storage efficiency was first discussed. The results proved that the CH 4 /CO 2 replacement has obvious advantages in CO 2 storage, and a maximum CO 2 storage efficiency of 96.73% was achieved by combined method. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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