四丁基溴化铵-二氧化碳-水体系半笼水合物相平衡数据的测定

Phase equilibrium data measurement of semi-clathrate hydrates for tetra-n-butyl ammonium bromide-carbon dioxide-water

水合物相平衡数据是利用水合物捕集二氧化碳的基础数据,利用定容逐步加热的方法测量了四丁基溴化铵-二氧化碳-水三元体系水合物的相平衡数据,实验测量的压力和温度分别为1.0—4.3 MPa,282.75—292.15 K,四丁基溴化铵水溶液的质量分数为5%—30%。实验结果表明:在一定的温度条件下,与纯水中二氧化碳水合物形成条件相比,添加四丁基溴化铵降低了水合物的形成压力,说明添加四丁基溴化铵利于二氧化碳水合物的形成,是二氧化碳水合物形成的促进剂。随着四丁基溴化铵水溶液质量分数的增大,水合物相平衡压力下降幅度也增大,这表明四丁基溴化铵高质量分数体系中二氧化碳水合物的稳定性好,水合物生长的推动力大。

The phase equilibrium data of carbon dioxide hydrate is fundamental data for capturing carbon dioxide with hydrates. By using isochoric step-heating method the phase equilibrium data for tetra-n-butyl ammonium bromide （TBAB）-carbon dioxide-water mixtures were experimentally studied and reported at 1.0-4.3 MPa, 282.75- 292.15 K, and with TBAB aqueous solution mass faction of 5%-30%. The experimental results indicate that the presence of TBAB decreases the formation pressure of carbon dioxide double semi-elathrate hydrate in the experimental temperature range, and TBAB is beneficial to carbon dioxide hydrate formation. It also shows that TBAB is a good promoter for carbon dioxide hydrate formation. Moreover, pressure reduction is dependent on the TBAB mass fraction. Carbon dioxide hydrate is more stable with the increase of the mass fraction of TBAB aqueous solution. It presents that the driving force of carbon dioxide hydrate growth becomes greater with the increase of the mass fraction of TBAB.