摘要
利用自制恒温测量热重装置,研究了微量硫对钙基吸收剂脱碳的影响和脱碳失活剂继续用于烟气脱硫的硫酸化特性,提出用破碎法解决脱碳过程累计硫化对失活剂再脱硫的影响。结果表明：SO_2浓度增加,吸收剂脱碳能力衰减加剧,随循环增加,小粒径石灰石衰减程度比大粒径严重;再脱硫时,碳化阶段SO_2浓度增加,失活剂再脱硫效能力下降;SO_2浓度一定时,随循环增加,0.075～0.097 mm粒径的失活剂脱硫率逐渐降低,0.15～0.25 mm和0.355～0.45 mm粒径的样品5次循环后硫化率较高（接近未循环吸收剂）然后逐渐下降,BD和SD石灰石规律相似,原因是循环增加造成孔径分布改变和脱碳过程累计硫化对再脱硫影响的综合作用;失活剂破碎打破了Ca SO_4膜对未反应CaO核的包围,所以再脱硫率比直接脱硫高。
By means of a customized thermogravimetric analysis system that can measure weight change of samples at constant temperature,the effect of trace SO_2 on Ca-based sorbents cyclic CO_2 capture and the sulfation behavior of deactivated sorbents after different cycles were studied. Solution of crushing deactivated sorbents was put forward to solve the influence of accumulated sulfation product layer formed during CO_2 cupture on followed SO_2 retention. The results show that CO_2 capture ability of deactivated sorbents decreases rapidly as the SO_2 concentration increases,and the phenomenon of small particle size limestone is more obvious than that of big one with the number of cycles. During the followed SO_2 retention,sulfation conversion decreases with the concentration of SO_2 in the carbonation atmosphere increasing. The sulfation conversion of sorbents with particle size in the range of 0. 075 ～ 0. 097 mm decreases with the number of cycles,however,sorbents with particle size in the range of 0. 15 ～ 0. 25 mm and 0. 355 ～ 0. 45 mm reach a relatively higher conversion（ close to fresh sorbent） with 5 cycles,properties of BD and SD limestone are similar. Reasons are comprehensive effect of pore size distribution changes with the number of cycles and effect of sulfation behavior during carbonation on followed SO_2 retention. The crushed deactivated sorbents have higher conversion than that of direct sulfation because the unreacted CaO core is liberated from CaSO_4 film.
出处
《华北电力大学学报（自然科学版）》
CAS
北大核心
2016年第3期81-87,共7页
Journal of North China Electric Power University：Natural Science Edition
基金
国家自然科学基金资助项目(51276064)
关键词
钙基吸收剂
失活
SO2浓度
再脱硫
粒径
破碎
Ca-based sorbent
deactivation
concentration of SO2
followed SO2 retention
particle size
crush
