WANG Xiaohui, XU Qiang, ZHENG Huaxing, SUN Changyu, CHEN Guangjin. Energy efficiency analysis of natural gas hydrates production method[J]. CIESC Journal, 2020, 71(12): 5754-5762
WANG Xiaohui, XU Qiang, ZHENG Huaxing, SUN Changyu, CHEN Guangjin. Energy efficiency analysis of natural gas hydrates production method[J]. CIESC Journal, 2020, 71(12): 5754-5762DOI: 10.11949/0438-1157.20200360.
Energy efficiency analysis of natural gas hydrates production method
The decomposition of natural gas hydrates is a phase change process
which involves the consumption and conversion of various forms of energy
such as electrical energy
chemical energy
and thermal energy. In order to evaluate the economy capacity of natural gas hydrates exploitation
an exergy model was established to calculate the energy efficiency ratio (EER) of hydrate production method. The CO
2
replacement method is taken as a case study to introduce the calculation equation and flow chart of energy efficiency ratio in any production period. The amount of CO
2
injection
gas production and mole fraction of methane in produced gas are three key parameters in the process of CO
2
replacement. The ratio between the amount of gas production and CO
2
injection is defined as production injection ratio to eliminate the influence of deposit size. This work studied the influence of production injection ratio and the mole fraction of methane in produced gas on EER. The results show that the EER of gas hydrates production by CO
2
replacement is between 0.31 and 6.4 under the set conditions
and it increases with the increase of production injection ratio. In addition
increasing the mole fraction of methane in produced gas can reduce the energy consumption for gas separation and increase EER. Therefore
there are two effective ways to increase EER of CO
2
replacement through controlling the amount of gas production and the mole fraction of methane in produced gas. The EER model is established to provide guidance for the optimization of gas hydrate mining process.
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references
陈光进, 孙长宇, 马庆兰. 气体水合物科学与技术[M]. 北京: 化学工业出版社, 2008.
Chen G J, Sun C Y, Ma Q L. Gas Hydrate Science and Technology [M]. Beijing: Chemical Industry Press, 2008.
Chong Z R, Yang S H B, Babu P, et al. Review of natural gas hydrates as an energy resource: prospects and challenges [J ] . Applied Energy, 2016, 162 : 1633-1652.
Boswell R, Collett T S. Current perspectives on gas hydrate resources[J ] . Energy & Environmental Science, 2010, 4 (4): 1206-1215.
Zhou S W, Chen W, Li Q P, et al. Research on the solid fluidization well testing and production for shallow non-diagenetic natural gas hydrate in deep water area[J ] . China Offshore Oil Gas, 2017, 29 (4): 1-8.
Zhao J Z, Li H T, Zhang L H, et al. Large-scale physical simulation experiment of solid fluidization exploitation of marine gas hydrate[J ] . Natural Gas Industry, 2018, 38 (10): 76-83.
Sun J, Ning F, Liu T, et al. Gas production from a silty hydrate reservoir in the South China Sea using hydraulic fracturing: a numerical simulation[J ] . Energy Science and Engineering, 2019, 7 : 1106-1122.
Wang B, Dong H S, Fan Z, et al. Numerical analysis of microwave stimulation for enhancing energy recovery from depressurized methane hydrate sediments[J ] . Applied Energy, 2020, 262 : 114559.
Sun Y F, Wang Y F, Zhong J R, et al. Gas hydrate exploitation using CO2/H2 mixture gas by semi-continuous injection-production mode[J ] . Applied Energy, 2019, 240 : 215-225.
Yang X, Sun C Y, Su K H, et al. A three-dimensional study on the formation and dissociation of methane hydrate in porous sediment by depressurization[J ] . Energy Conversion & Management, 2012, 56 (2): 1-7.
Li J, Liang Z J, Wang Z L, et al. Characterization of microscopic nature of methane hydrate decomposition by different molecular models[J ] . CIESC Journal, 2020, 71 (3): 955-964.
Li S X, Li J, Jin Y R. Depressurizing dissociation of natural gas hydrate with different saturation[J ] . CIESC Journal, 2014, 65 (4): 1411-1415.
Sun X, Luo T T, Wang L, et al. Numerical simulation of gas recovery from a low-permeability hydrate reservoir by depressurization[J ] . Applied Energy, 2019, 250 : 7-18.
Zhou X B, Liu C J, Luo J Q, et al. Microscopic measurements on methane hydrate dissociation[J ] . CIESC Journal, 2019, 70 (3): 1042-1047.
Grover T, Holditch S A, Moridis G. Analysis of reservoir performance of messoyakha gas hydrate field[C]//Proceedings of the International Offshore and Polar Engineering Conference. 2008.
Falser S, Uchida S, Palmer A C, et al. Increased gas production from hydrates by combining depressurization with heating of the wellbore[J ] . Energy & Fuels, 2012, 26 (10): 6259-6267.
Ruan X K, Li X S, Xu C G, et al. Numerical simulation of gas production from hydrate by depressurization combined with well-wall heating[J ] . CIESC Journal, 2015, 66 (4): 1544-1550.
Li S X, Zheng R Y, Xu X H, et al. Energy efficiency analysis of hydrate dissociation by thermal stimulation[J ] . Journal of Natural Gas Science & Engineering, 2016, 30 : 148-155.
Yuan Q, Sun C Y, Wang X H, et al. Experimental study of gas production from hydrate dissociation with continuous injection mode using a three-dimensional quiescent reactor[J ] . Fuel, 2013, 106 (4): 417-424.
Feng J C, Wang Y, Li X S, et al. Production performance of gas hydrate accumulation at the GMGS2-Site 16 of the Pearl River Mouth Basin in the South China Sea[J ] . Journal of Natural Gas Science & Engineering, 2015, 27 : 306-320.
Feng J C, Wang Y, Li X S, et al. Investigation into optimization condition of thermal stimulation for hydrate dissociation in the sandy reservoir[J ] . Applied Energy, 2015, 154 : 995-1003.
Feng J C, Wang Y, Li X S. Energy and entropy analyses of hydrate dissociation in different scales of hydrate simulator[J ] . Energy, 2016, 102 : 176-186.
Li S, Zheng R, Xu X, et al. Energy efficiency analysis of hydrate dissociation by thermal stimulation[J ] . Journal of Natural Gas Science and Engineering, 2016, 30 : 148-155.
Sun Y F, Zhong J R, Li W Z, et al. Methane recovery from hydrate-bearing sediments by the combination of ethylene glycol injection and depressurization[J ] . Energy & Fuels, 2018, 32 (7): 7585-7594.
Zhao J F, Xu K, Song Y C, et al. A review on replacement of CH4 in natural gas hydrates by use of CO2[J ] . Energies, 2012, 5 (2): 399-419.
Wang M, Wang X, Deng C, et al. Process modeling and energy efficiency analysis of natural gas hydrate production by CH4-CO2/H2 replacement coupling steam methane reforming[J ] . Computer Aided Chemical Engineering, 2019, 47 : 131-136.
王晓辉. 注气开采天然气水合物实验模拟与能效分析[D]. 北京: 中国石油大学, 2017.
Wang X H. Experimental simulation and energy efficiency analysis of gas hydrates production by gas injection method[D]. Beijing: China University of Petroleum (Beijing), 2017.
Teng Y F, Zhang D X. Long-term viability of carbon sequestration in deep-sea sediments[J ] . Science Advances, 2018, 4 : eaao6588.
刘玉亮. LNG公路槽车运输经济性研究评价[J ] . 时代金融, 2013, 27 : 293.
Liu Y L. Study on the economy of LNG transportation by tank car[J ] . Times Finance, 2013, 27 : 293.
Mallon W, Buit L, Wingerden J V, et al. Costs of CO2 transport ation infrastructures [J ] . Energy Procedia, 2013, 37 : 2969-2980.
Yuan Q, Sun C Y, Yang X, et al. Recovery of methane from hydrate reservoir with gaseous carbon dioxide using a three-dimensional middle-size reactor[J ] . Energy, 2012, 40 (1): 47-58.
Yuan Q, Sun C Y, Liu B, et al. Methane recovery from natural gas hydrate in porous sediment using pressurized liquid CO2[J ] . Energy Conversion and Management, 2013, 67 : 257-264.