水合物法分离乙烯裂解气的相平衡研究

对水合物法分离乙烯裂解气的气固(水合物)相平衡进行了研究,考察了系统温度、系统压力、初始气液比对分离效果的影响。实验中考察的系统温度、系统压力和初始气液体积比范围分别为268.15~276.15K,4.0~5.0M Pa,140~200。实验结果表明,分离效果随系统温度的降低或系统压力的升高而改善;随初始气液体积比的降低也有一定程度的改善,但不明显。典型的裂解气经一次水合,C2+组分在原料气中的摩尔分数可由37.39%降至4.79%,经二次水合可进一步降到1.02%,显示出良好的工业应用前景。较佳的操作条件为:系统温度268.15K,系统压力5.0M Pa,初始气液体积比140。

Study on Vapor-Hydrate Phase Equilibrium in Separation of Ethene Pyrolysis Gases by Forming Hydrates

Vapor-hydrate phase equilibrium in separation of ethylene pyrolysis gases by forming hydrates was studied.Effects of system temperature,system pressure and initial gas-liquid ratio upon separation efficiency were investigated.In experiments feed gas contacted with water and formed hydrates at given system temperature and pressure in a high-pressure sapphire cell.When vapor-hydrate phase equilibrium was established,gas phase was sampled and analyzed.The residual gas in cell was let out.The hydrate decomposed by heating the system and the obtained gas was analyzed.The result was taken as composition of hydrate phase on dry basis.Ranges of experimental temperature,pressure and initial gas-liquid volume ratio were 268.15-276.15K,4.0-5.0MPa and 140-200,respectively.The separation efficiency was obviously enhanced by lowering of system temperature or raising of system pressure,but only slightly improved by decrease of gas-liquid volume ratio.Mole fraction of C~+_2 component in feed gas could be reduced from 37.39% to 4.79% by once through hydration for a typical ethylene pyrolysis gas composition,and could be further decreased to 1.02% by another following hydrations.Separation of ethylene pyrolysis gases by forming hydrates was promising.Optimal operating conditions were:system temperature 268.15K,system pressure 5.0MPa,initial gas-liquid volume ratio 140.