变参数对深冷烟气脱硫效果的影响

Influence of varying parameters on desulfurization effect of cryogenic flue gas

为了减少烟气中SO2的排放,提出了对烟气中的SO2进行深冷液化分离的脱硫方法。基于Aspen plus建立了一种深冷脱硫流程,选用SRK(Soave Redich-Kwong)物性方法对流程进行稳态模拟,研究了深冷温度、深冷压力和SO2浓度对深冷液化分离效果的影响规律。搭建了深冷脱硫试验台,进行了试验验证。研究发现,对于SO2质量浓度为1 000 mg/m3的烟气,深冷压力为500 kPa时,深冷温度从-15℃降至-45℃过程中,SO2脱除效率从40.2%增加到73.2%;深冷温度在-45℃时,从500 kPa增加到4 000 kPa过程中,脱除效率从73.2%提高到92.9%;提高SO2浓度有利于提高脱除效率。综合结果表明,深冷液化分离系统具有较好的液化和分离效果。若SO2脱除效率在80%以上时,其工艺参数范围为:深冷温度低于-35℃,深冷压力高于2 000 kPa。

To reduce the emissions of sulfur dioxide(SO2), a desulfurization method which was based on liquefaction and separation of SO2 by chilling the flue gas was put forward. The cryogenic desulfurization process was designed based on Aspen plus. The steady state process was simulated using SRK(Soave-Redich-Kwong) method, and the effects of temperature, pressure and concentration of SO2 on the separation efficiency of cryogenic desulfurization were analyzed. A cryogenic desulfurization test bench was built and the verification experiments were carried out. It was found that when the mass concentration of SO2 was 1 000 mg/m3, SO2 removal efficiency increased from 40.2% to 73.2% when the temperature of fuel gas decreased from-15 ℃ to-45 ℃ at 500 kPa;the removal efficiency can be improved by increasing SO2 concentration. The comprehensive results show that cryogenic desulfurization system has good liquefaction and separation efficiency. To keep the SO2 removal efficiency above 80%, the process parameter range for the system should be under-35 ℃ and above2 000 kPa.