赵建涛, 黄戒介, 卫小芳, 房倚天, 王 洋. 钛酸锌高温煤气脱硫剂再生行为的研究[J]. 燃料化学学报(中英文), 2007, 35(01): 66-71.
引用本文: 赵建涛, 黄戒介, 卫小芳, 房倚天, 王 洋. 钛酸锌高温煤气脱硫剂再生行为的研究[J]. 燃料化学学报(中英文), 2007, 35(01): 66-71.
ZHAO Jiantao, HUANG Jiejie, WEI Xiaofang, FANG Yitian, WANG Yang. 钛酸锌高温煤气脱硫剂再生行为的研究[J]. Journal of Fuel Chemistry and Technology, 2007, 35(01): 66-71.
Citation: ZHAO Jiantao, HUANG Jiejie, WEI Xiaofang, FANG Yitian, WANG Yang. 钛酸锌高温煤气脱硫剂再生行为的研究[J]. Journal of Fuel Chemistry and Technology, 2007, 35(01): 66-71.

钛酸锌高温煤气脱硫剂再生行为的研究

钛酸锌高温煤气脱硫剂再生行为的研究

  • 摘要: 在热天平装置上研究了再生反应温度、反应气体中氧气体积分数、脱硫剂颗粒粒径对钛酸锌高温煤气脱硫剂再生行为的影响。实验结果表明,较高的反应温度和氧气体积分数,较小的颗粒粒径有利于提高脱硫剂的再生反应速率。由于二次反应的影响,脱硫剂再生过程中有硫酸盐生成,提高反应温度或降低反应气体的氧气体积分数可以减少硫酸盐的生成。利用收缩核模型对其动力学行为进行了分析,结果表明,脱硫剂的再生过程存在动力学控制步骤的转移。脱硫剂再生转化率较低(<65%)时,再生过程主要受化学反应控制;再生转化率较高(>75%)时,再生过程主要受颗粒内扩散控制。表观化学反应速率常数的指前因子为8.01×10-2 m/s,活化能为19.11 kJ/mol;有效扩散系数的指前因子为3.12×10-4 m2/s,扩散活化能为48.84 kJ/mol。

     

    Abstract: The Regenerable Zinc titanate sorbent is one of the leading candidates for hot coal-derived gas desulfurization. The effect of the regeneration temperature, O2 concentration and sorbent granular size on the regeneration reactivity of Zn2TiO4 sorbent were investigated by using the thermogravimetric analyzer. Zinc sulfate formed through side reactions was inferred from TGA curves and was confirmed by the XRD analysis when the sorbent was regenerated at higher concentration of the oxygen and lower temperature(<750℃). The reasonable regeneration conditions should avoid the sulfate formation. Regeneration kinetic studies were also performed at regeneration temperature from 725℃ to 800℃. Higher regeneration temperature and O2 concentration, smaller granular size can increase the regeneration rate. The order of O2 in the reaction can reasonably be assume to be 1. Kinetic model tests show that the regeneration process can be well fitted by the shrinking core model. The kinetic controlling steps transfer with the sorbent conversion. The chemical reaction rate is the controlling step at the early regenerating stage (<65%), while the inner diffusion through the product layer play a dominant role at the latter regenerating stage (>75%). The reaction rate constants and the effective diffusivities were calculated according the model. The apparent activation energy of chemical reaction and corresponding frequency factor are 19.11kJ/mol and 8.01×10-2m/s, respectively. While the diffusion activation energy and corresponding frequency factor are 48.84kJ/mol and 3.12×10-4m2/s, respectively.

     

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