可燃生活垃圾气化Ca-Fe复合金属氧化物的原位固硫性能

In-situ sulfur fixation performance of Ca-Fe composite metal oxides during gasification of combustible municipal solid waste

气化技术可有效缓解因可燃生活垃圾产量不断增加而衍生的环境问题,但仍需要对气化产生的HS和SO进行脱除以降低硫污染物排放风险。可燃生活垃圾组成的复杂性决定了需要开发适宜的双效固硫剂以对HS和SO一步脱除。原位固硫指将气化原料与固硫剂预先混合,气化与硫脱除同时进行且硫污染物被固定于灰渣中。本文使用聚苯乙烯颗粒、木屑等典型组分配制可燃生活垃圾作为气化原料,以CO为气化剂,采用球磨法制备了一系列Ca-Fe复合金属氧化物作为固硫剂并对其原位固硫性能进行了研究。结果表明,在600℃气化温度下,Ca-Fe复合金属氧化物中的CaO/FeO比例对固硫率产生影响,且两者质量比为1∶1时固硫性能最佳,固硫率可达82.65%。作为对比,CaO和FeO单一组分固硫率仅分别为65.57%和74.12%。BET、SEM等分析表明CaO、FeO球磨形成复合金属氧化物时产生相互作用并影响粒径分布、孔径、比表面积等物化性质,且能够改善固硫剂的烧结现象,质量比为1∶1时综合作用效果最优。

Gasification technology can effectively alleviate the environmental threat caused by the increasing combustible municipal solid waste, but the HS and SOproduced by gasification still need to be removed to reduce the sulfur emission. The complex composition of combustible municipal solid waste requires suitable sulfur fixation reagent to remove HS and SOsimultaneously. In-situ sulfur fixation refers to the co-occurrence of gasification and sulfur removal after premixing raw materials and sulfur fixation reagent, and the sulfur pollutants are fixed in the ash. In this work, the typical components such as polystyrene particles and sawdust were mixed to simulate the combustible municipal solid waste and COwas used as gasification agent. A series of Ca-Fe composite metal oxides were prepared by ball milling method and their in-situ sulfur fixation performance were further studied. The results showed that at 600℃, CaO/FeOmass ratio in Ca-Fe composite metal oxides has affected on the sulfur fixation rate. The sulfur fixation rate reached 82.65% when 1∶ 1 Ca-Fe composite metal oxides were used, better than other CaO/FeOmass ratios. In contrast, the sulfur fixation rates of using CaO and FeOsolely were only 65.57% and 74.12% respectively. BET and SEM analysis showed the interactions between CaO and FeOduring the composite metal oxides formation by ball milling, which affected the physico-chemical properties such as particle size distribution(PSD), pore size and specific surface area. Besides, the sintering phenomenon was much alleviated. Therefore, the best comprehensive performance was for the CaO/FeOmass ratio of 1∶1.