分别测定了煤气化合成气在纯水以及两种不同浓度(6%(mol)和5%(mol)的四氢呋喃(THF)水溶液中的水合物生成条件,实验结果表明THF的加入可以大大降低合成气生成水合物的压力,使合成气能够在较低的压力下通过生成水合物的方法得到分离,同时也为该分离方法应用于实际工业装置提供了可行性。研究还成功地将Chen-Guo水合物热力学模型应用到含有一氧化碳气体的水合物生成条件的预测,并对合成气在纯水中不同温度下生成水合物的压力进行了计算,与本次实验值比较,得到平均误差为8.64%,肯定了实验结果的准确性。在此基础上,选定在5%(mol)THF水溶液中,气液比为100:1,反应压力为5MPa(绝)的条件下,分别进行反应温度为279.15K、281.15K、283.15K、284.15K和285.15K的水合物法分离合成气实验,提浓其中的氢气和一氧化碳。实验结果表明,284.15K时,氢气的回收率达到79.8%,氢气和一氧化碳的总回收率为76.0%,分离后二者总的体积百分含量由原料气中的88%提高到93%,分离效果较为满意。
The formation conditions of syngas hydrates in pure water and in tetrahydrofuran(THF) solutions with different concentrations(6%(mol) and 5%(mol)) were determined respectively.The results show that the THF can reduce the formation pressure of he syngas hydrates dramatically.It ensures that the syngas can be separated via hydrate formation under low pressure,which offers the availableness of using this separation method to the real industrial device.The Chen-Guo hydrate thermodynamic model was used to calculate the formation pressure of syngas hydrates formed in pure water at different temperatures,and the average deviation from the experimental values is 8.64%,which also indicates that the accuracy of the experimental data is satisfactory.It was also found that the Chen-Guo hydrate thermodynamic model cab be successfully applied to predict the hydrate formation conditions of the CO containing gas.On this basis,a reaction system with 5%(mol) THF solution,the vapor-to-water ratio of 100:1 and the reaction pressure of 5.0 MPa was selected;the separation experiments were conducted orderly at 279.15~285.15 K,and the H2 and CO in syngas were meant to be condensed.The results show that,at 284.15 K,the recovery ratio of H2,both H2 and CO are respectively 79.8% and 76.0%,and their volume percentage after separation increases from 88%(in raw gas) to 93%,which reflects a satisfactory separation effect.