电石渣是典型的高钙工业固体废弃物,具有优异的CO2吸收性能,但是在钙循环中纯电石渣的反应活性和CO2吸收性能会随着循环次数的增加而降低.本文以电石渣为钙源,以MgO和ZnO为掺杂剂合成高效稳定的钙镁锌复合吸收剂,在固定床反应器中探究了合成工艺条件及掺杂量对复合吸收剂CO2吸收性能的影响,以及循环吸收过程中吸收剂内部结构的变化.结果表明,利用干物理混合法合成的吸收剂比湿混合法具有更丰富的孔隙结构,Mg和Zn元素在电石渣表面分散均匀,有效改善了电石渣的抗烧结性能和反应活性,改性后的复合吸收剂在循环过程中具有更高的CO2吸收性能,且20次循环后,干物理混合法合成的复合吸收剂CO2吸收量仍可达0.42 g/g.
Carbide slag is a typical high calcium industrial solid waste with excellent CO2 absorption performance,but the reaction activity and CO2 absorption performance of pure carbide slag in calcium cycling will decrease with the increase of cycling times.Efficient and stable calcium-magnesium zinc composite absorbents was synthesized using carbide slag as the calcium source,MgO and ZnO as dopants.Effects of synthesis process conditions and doping amount on the absorption performance of CO2 composite absorbent were investigated in a fixed bed reactor,as well as the changes in the internal structure of the absorbent during cyclic absorption.The results show that the absorbent synthesized by dry physical mixing method has a richer pore structure than wet mixing method.Mg and Zn elements are evenly dispersed on the surface of the carbide slag,effectively improving the anti-sintering performance and reaction activity of the carbide slag.The modified composite absorbent has higher CO2 absorption performance during the cycling process,and after 20 cycles,CO2 absorption capacity of the composite absorbent synthesized by dry physical mixing method can still reach 0.42 g/g.