电石渣改性制备高效CO_(2)复合吸收剂

High Efficiency CO_(2)Composite Absorbent Prepared by Modification of Carbide Slag

电石渣是典型的高钙工业固体废弃物,具有优异的CO_(2)吸收性能,但是在钙循环中纯电石渣的反应活性和CO_(2)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CO_(2)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CO_(2)吸收性能,且20次循环后,干物理混合法合成的复合吸收剂CO_(2)吸收量仍可达0.42 g/g。

Carbide slag is a typical high calcium industrial solid waste with excellent CO_(2)absorption performance,but the reaction activity and CO_(2)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 CO_(2)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 CO_(2)absorption performance during the cycling process,and after 20 cycles,CO_(2)absorption capacity of the composite absorbent synthesized by dry physical mixing method can still reach 0.42 g/g.