燃煤电厂氨法联合脱硫脱碳研究

摘要

利用氨法同时进行CO2捕集和SO2脱除是一种比较有潜力的污染物减排技术.本文以填料塔为反应器,研究氨水的质量分数、氨水温度、吸收液体积流量、模拟烟气体积流量和不同添加剂等因素对氨法联合脱除CO2/SO2的效率和吸收量的影响.结果表明:在SO2浓度较低的情况下,脱硫效率接近100％;氨水浓度的增加能够显著提高CO2脱除率和吸收量,氨质量分数为10％时可以达到近90％的CO2脱除率;氨水温度的升高会降低CO2脱除率和吸收量;增加吸收液流量和减少烟气流量均会增大脱碳率,即较高的液气比可以实现较高的脱碳率;在氨水中加入乙醇、聚乙二醇二甲醚(NHD)和乙醇胺(MEA)等添加剂会显著提高CO2脱除率和吸收量.通过分析某燃煤电厂1 000 MW超低排放机组烟气参数可以看出,在超低排放和降低碳排放强度的双重要求下,氨法联合脱硫脱碳在燃煤电厂中应用的可行性较高.%Combined capture of CO2 and SO2 by using ammonia aqueous is a relatively potential pollutant reduction technology.A packed tower was chosen as the reactor,in which CO2 and SO2 in simulated flue gas were absorbed by ammonia aqueous,and the simulated flue gas was mainly comprised of pure CO2,SO2 and compressed air.The effects of several factors on CO2 and SO2 removal efficiency and absorption rate were studied,such as mass fraction of the ammonia,temperature of the ammonia aqueous,flow rates of the absorbent and simulated flue gas,and additives.The results show that,the SO2 removal efficiency reached nearly 100％ when its inlet concentration was low.The increase of ammonia mass fraction can obviously improve the CO2 removal efficiency and absorption rate,and the CO2 removal efficiency can reach nearly 90％ when the ammonia mass fraction was 10％.The experimental results also indicated that the increasing ammonia aqueous temperature can distinctly decrease the CO2 removal efficiency and absorption rate,and a pretty high CO2 removal efficiency can be obtained when flow rate of the absorbent was high and that of the simulated flue gas was low.Adding ethanol,polyethyleneglycol dimethyl ether (NHD) and monoethanolamine (MEA) can effectively enhance the CO2 removal efficiency and absorption rate.Taking the flue gas parameters of a 1 000 MW ultra-low emission unit as a reference,the combined capture of SO2 and CO2 in coal-fired power plant has pretty feasibility,especially with the two requirements of ultra-low emission and decreasing carbon emission intensity.