Ca-Based Sorbents Modified with Humic Acid for Flue Gas Desulfurization
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- 作者：Rongfang Zhao ; Haidi Liu ; Shufeng Ye ; Yusheng Xie ; Yunfa Chen
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2006
- 出版时间：October 11, 2006
- 年：2006
- 卷：45
- 期：21
- 页码：7120 - 7125
- 全文大小：361K
- 年卷期：v.45,no.21(October 11, 2006)
- ISSN：1520-5045
文摘
With humic acid (HA) as a special additive, modified Ca(OH)2 sorbents referred to as M-Ca(OH)2-iHA,where i is the weight percentage of HA in the dry product and is in the range between 0 to 10, were preparedby hydrating CaO with water in which the expected amount of HA had been dissolved. The physicochemicalproperties of the sorbents were characterized using SEM, XRD, BET, etc., and the desulfurization activity ofthe sorbents, expressed as "Ca utilization", was investigated in a differential fixed-bed quartz reactor underisothermal conditions at 65 
C and 70% relative humidity. The experimental results indicate that both hydrationtreatment and HA modification play important roles in improving the microstructure and desulfurization activityof M-Ca(OH)2-iHA. In particular, hydration treatment is the key contribution to M-Ca(OH)2-0HA, whereasboth factors are significant for M-Ca(OH)2-iHA (i = 4, 6, 8, 10). It was also found that the microstructureand desulfurization activity of M-Ca(OH)2-iHA improves considerably as i increases from 0 to 8 and thenlevels out when i increases further to 10. That is, M-Ca(OH)2-8HA has almost the optimal microstructureamong the sorbents prepared in this study, i.e., volume mean diameter of 0.5 
m, BET surface area of 19.29m2/g, and mesopore volume of 0.084 cm3/g, as well as the highest desulfurization activity, Ca utilization of0.52 mol of SO2/mol of Ca. In addition, the mechanism of HA modification might be due to the accelerationeffect of HA on the dissolution of lime, as well as the disturbance effect of Ca2+-HA chelates on the nucleationand growth processes of Ca(OH)2 crystals.
C and 70% relative humidity. The experimental results indicate that both hydrationtreatment and HA modification play important roles in improving the microstructure and desulfurization activityof M-Ca(OH)2-iHA. In particular, hydration treatment is the key contribution to M-Ca(OH)2-0HA, whereasboth factors are significant for M-Ca(OH)2-iHA (i = 4, 6, 8, 10). It was also found that the microstructureand desulfurization activity of M-Ca(OH)2-iHA improves considerably as i increases from 0 to 8 and thenlevels out when i increases further to 10. That is, M-Ca(OH)2-8HA has almost the optimal microstructureamong the sorbents prepared in this study, i.e., volume mean diameter of 0.5 m, BET surface area of 19.29m2/g, and mesopore volume of 0.084 cm3/g, as well as the highest desulfurization activity, Ca utilization of0.52 mol of SO2/mol of Ca. In addition, the mechanism of HA modification might be due to the accelerationeffect of HA on the dissolution of lime, as well as the disturbance effect of Ca2+-HA chelates on the nucleationand growth processes of Ca(OH)2 crystals.© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |