氨法烟气CO_2捕集工艺二次污染控制研究

Study on the Secondary Pollution Control in CO_2 Capture by Aqueous Ammonia Process

以低温烟气CO2捕集工艺含氨废气废水污染控制为目的,提出以废水替代循环洗水的2级脱氨和分级精馏技术方案。计算绘制了低温低浓度NH3-CO2-H2O气液平衡曲线图,进行了NH3与CO2同时吸收传质分析和参数预测,结果表明不需增加精馏能耗即可同时达到尾气NH3含量<10 mg/m3和废水氨浓度<15 mg/L的污染控制标准。

Aimed at the secondary pollution control of ammonia-containing wastewater and exhaust gas from the chilled ammonia based CO2 capture process,a method was proposed to use waste water partly replacing process water for two stage ammonia washing and to remove the absorbed ammonia by two stage rectification. Referring to the low temperature and low concentration conditions involved in the process,the VLE data of NH3- CO2- H2 O system was calculated. On the basis of the VLE curves,mass transfer analysis was made to the simultaneous absorption of NH3 and CO2. The results show that the ammonia pollution control standards of 10 mg / m3 for exhaust gas and 15 mg / L for wastewater both can be satisfied without increasing energy consumption for distillation.