中文摘要：

本实验着重研究了纯水、质量分数为3.4%和5.0%的NaCl溶液中,甲烷-二氧化碳混合气体水合物的生长速率以及气体在水合物相中分布规律。研究结果表明水合物生成过程中对甲烷和二氧化碳的吸收存在一定的选择性。二氧化碳在水合物晶核生长初期更容易被捕获,表明二氧化碳更易于占据水合物中大笼,同时有利于稳定水合物的晶体结构。NaCl的存在提高了水合物三相平衡压力,降低了水合物的气体消耗总量。随着溶液中初始盐浓度的提高,水合物生长初期对二氧化碳的选择性吸收得到了强化。表明溶液中NaCl浓度的上升提高了水合物晶核的不稳定性同时抑制了晶核生成。因此,NaCl对水合物的生长过程具有一定的抑制作用。

英文摘要：

To study the influence of salinity on hydrate growth rates and gas distributions in hydrate phase,gas hydrates were crystallized in pure water,3.4%,5.0%sodium chloride solution respectively using CH_4-CO_2 gas mixtures.Results showed that the gases needed for crystallization were selective to methane and carbon dioxide.CO_2 molecules were easier to be captured during the growth of the nucleus of crystal,suggesting the preferential enclathration of CO_2 molecules in the large hydrate cages and better capability in stabilizing hydrate structure.The hydrate-liquid-vapor phase equilibrium pressures were elevated and the total gas consumptions were reduced due to the existence of NaCl.The preferential consumptions of CO_2 were also enhanced with the increasing NaCl concentrations.A rise in NaCl concentration would weaken the stability of hydrate structure and inhibit the formation of hydrate nucleus.Therefore,NaCl has an inhibitive effect on hydrate crystallization.