煤制合成气低温甲醇洗吸收塔数学模拟与分析  

Analysis and mathematical simulation of absorbing tower in rectisol process for coal based syngas

作　　者：肖珍平[1,2] 马宏方[1] 应卫勇[1] 房鼎业[1] 

机构地区：[1]华东理工大学大型工业反应器工程教育部工程中心化学工程联合国家重点实验室,上海200237 [2]中国石化集团宁波工程有限公司,浙江宁波315207

出　　处：《煤炭学报》2013年第12期2247-2252,共6页Journal of China Coal Society

摘　　要：为寻求低温甲醇洗合适的热力学模型,建立了低温甲醇吸收气体的SRKH模型,通过参数回归得到低温甲醇洗体系中组分之间NRTL方程的二元交互作用参数,根据气液平衡计算验证了参数的可靠性。模拟计算了国内某厂低温甲醇洗的吸收塔,得到了CO2和H2S在吸收塔中的摩尔分数分布,计算结果表明所得到的热力学模型对低温甲醇洗系统是适宜的。考察了工业生产中操作条件对低温甲醇洗系统的影响,获得了净化气中CO2和H2S摩尔分数随操作条件的变化规律。随精洗甲醇流量的增加以及甲醇温度的降低,低温甲醇洗后净化气中酸性气体的摩尔分数降低,H2S摩尔分数快速降低到0.1×10-6以下,因此通过改变精洗甲醇的流量或改变甲醇的温度可以生产出合格的不同CO2摩尔分数的净化气。在保证净化气中酸性气体摩尔分数满足煤制气合成甲醇的要求的情况下,考察了粗煤气流量对精洗甲醇流量的影响,结果表明,随粗煤气流量的增加,精洗甲醇量增加,但增加程度逐渐减小,规模的增加有利于降低操作费用。In order to find an appropriate thermodynamic model of rectisol process,the SRKH model of low-temperature methanol absorption was established and parameter regression was used to abtain all binary interaction parameters of the NRTL equation for rectisol system. The correctness of the arguments was verified by the vapor-liquid equilibrium calculations. An industrial absorber in China was simulated and the CO2and H2S concentration distribution in the absorber was obtained. The results show that the SRKH model is suitable for rectisol system. The effects of operating conditions on rectisol system were investigated and the concentration variations of CO2and H2S in purified gas caused by the changes of operating conditions were obtained. The acidic gas concentration in purified gas decreases along with the increase of pure methanol flow or / and the decrease of methanol temperature and the concentration of H2S can be reduced to less than 0. 1 ×10-6quickly. Therefore,qualified gas with different CO2concentrations can be produced by changing the flow of pure methanol or methanol temperature. The effect of crude gas flow on pure methanol flow was also investigated when the concentration requirements of acidic gases in purufied gas of coal gasification methanol synthesis process were meet; and results show that the flow of pure methanol increased with the augment of crude gas flow and the extent of growth decreases gradually,which indicates that it is beneficial to enlarge the scale so as to reduceoperating cost in advanced coal chemical industry.

关 键 词：煤制合成气 低温甲醇洗 热力学 SRKH状态方程 NRTL方程 

分 类 号：TQ545[化学工程—煤化学工程]