飞灰对单乙醇胺和二乙醇胺溶液吸收CO_2效率的影响

Effect of fly ash on CO_2 removal efficiency using MEA and DEA solution

为了掌握燃煤烟气中飞灰对单乙醇胺(MEA)和二乙醇胺(DEA)溶液吸收CO_2效率的影响,在自行设计的乱堆不锈钢θ环填料塔内,采用液相加入飞灰的方式,进行了实验研究并考察了飞灰在溶液温度、液气比、填料高度和飞灰浓度等操作条件下的影响规律。结果表明:飞灰的存在使MEA、DEA溶液吸收CO_2的效率降低且随着飞灰浓度的提高其影响有增加趋势,而飞灰对CO_2吸收效率降低的影响与其化学成分关系不大;MEA溶液、MEA-飞灰溶液、DEA溶液和DEA-飞灰溶液吸收CO_2的效率随着溶液温度、液气比和填料高度的增加均呈增加趋势;随着溶液温度或填料高度的增加,飞灰对MEA溶液吸收CO_2效率的影响变化较小,而对DEA溶液则影响显著;随着液气比的提高,飞灰对MEA、DEA溶液吸收CO_2效率的负面影响有下降的趋势。分析表明,飞灰的影响主要是通过改变吸收液初始分布而实现的。

To master the effect of fly ash in coal-fired flue gas generated from power plants on CO2absorption efficiency by using MEA and DEA as the absorbents,experiments were carried out by using a self-designed packed column filled withθ-ring packing and introducing the fly ash into the liquid phase.The effect laws of the process conditions,including the solution temperature,the packed height,the liquid gas ratio and the fly ash concentration,on the fly ash action were studied.The results showed that the present of the fly ash can significantly reduce CO2absorption efficiency,and the effect of fly ash on the CO2absorption efficiency indicated an increasing tendency with the increase of the fly ash concentration,but this effect was not related to its chemical composition.With the increase of the solution temperature,the liquid-gas ratio and the packed height,CO2absorption efficiency of MEA solution,MEA-fly ash solution,DEA solution and DEA-fly ash solution showed a gradually increased tendency.With increasing solution temperature or packed height,the inhibiting effect of the fly ash on MEA almost kept invariability,but this effect on DEA was remarkable.With the increase of liquid-gas ratio,this effect was weakened.The analysis indicated that the effect of the fly ash can be achieved by changing the initial distribution of the absorption solution.