微富氧燃烧技术下氨法脱碳试验研究

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（1 kg 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 Study on Carbon Removal by Aqueous Ammonia under Oxy-enrich Combustion

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; ③ 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.