微富氧燃烧技术下氨法脱碳试验研究

Experimental Study on Carbon Removal by Aqueous Ammonia under Oxy-enrich Combustion

针对微富氧燃烧下烟气组分（CO2体积分数约30％～40％）,利用填料塔进行了氨法脱碳试验研究,考察了烟气CO2浓度、氨水浓度、吸收液pH值、氨水流量、烟气温度、烟气流量等因素对CO2脱除率的影响.试验结果表明：①随氨水浓度、吸收液pH值、氨水流量增加以及填料增多,CO2脱除率升高,但在pH值=10.5时出现一定波动;②烟气温度为50℃时,CO2脱除率最高;③当氨水中NH3质量分数大于4％时,烟气中CO2脱除率达90％以上,微富氧燃烧条件下,单位质量氨（1kg NH3）对烟气中CO2吸收质量为0.32 kg,脱碳效率是常规燃烧条件下的2倍多,因此采用微富氧燃烧有利于缩小吸收塔和再生塔的体积、降低能耗.

Experimental studies on carbon removal by aqueous ammonia under oxy-enrich combustion flue gas （30％～40％ v/v CO2） in a packed column were carried out.Effects of different operating and design parameters on CO2 removal efficiency,including concentration of CO2 in flue gas,concentration of aqueous ammonia,pH value of absorbent,aqueous ammonia flow rate,flue gas temperature,total flue gas flow rate and packing height,were investigated.The research results show that：① improving concentration of aqueous ammonia,improving pH value of absorbent and increasing flow rate of aqueous ammonia can increase removal efficiency of CO2 respectively; but when pH value is 10.5,a certain volatility of removal efficiency occurs; ② when gas temperature is 50 ℃,the removal efficiency is the highest; ④ when concentration of aqueous ammonia is greater than 4％,the removal efficiency is above 90％.Under oxy-enrich combustion 1 kg NH3 can absorb 0.32 kg CO2,which is twice greater than conventional combustion.Therefore using oxy-enrich combustion mode contributes to reducing the volume of the absorber and regeneration column,as well as energy consumption.