摘要
由于会引起蓝烟、酸沉积以及建筑腐蚀等问题,SO_(3)减排已成为当前燃煤污染物控制的热点问题。基于U型石英管在260~380℃对常见碱性吸附剂的SO_(3)脱除规律进行试验研究。试验结果表明,Mg(OH)_(2)比表面积与孔容均最大,在试验温度范围内SO_(3)脱除性能优于NaHCO_(3)、Ca(OH)_(2)和Na_(2)CO_(3)。SO_(3)脱除前期,温度升高会提高所用吸附剂的SO_(3)动态脱除效率,且Mg(OH)_(2)在380℃下第10 min时的脱除率高达84%;当SO_(3)脱除趋于饱和时,温度提高对所用吸附剂的SO_(3)动态脱除效率无明显影响。吸附动力学分析表明,Na_(2)CO_(3)对SO_(3)的吸附反应前期(0~40 min)基本符合反应控制的缩核模型,此时Na_(2)CO_(3)表面的化学反应主导SO_(3)的脱除反应,而内扩散控制的缩核模型仅在260℃时可较好的描述前40 min的脱除反应。而在吸附后期(50~100 min),表面反应控制和内扩散控制均可较好的描述该阶段的吸附过程,此时SO_(3)在产物层的内扩散与其在Na_(2)CO_(3)表面的化学反应共同主导SO_(3)的脱除反应。
Due to blue smoke,acid deposition and building corrosion,the control of SO_(3)emission has become a hot issue during the coal burning.The removal characteristics of SO_(3)by common alkaline adsorbents were studied on a U-shaped quartz tube in the range of 260-380℃.The experimental results show that Mg(OH)_(2)has the largest specific surface area and pore volume,and its removal performance of SO_(3)was better than that of NaHCO_(3),Ca(OH)_(2),and Na_(2)CO_(3).The SO_(3)dynamic removal efficiency of the adsorbent will be improved with the increase of temperature in the early stage of SO_(3)removal,and the removal rate of Mg(OH)_(2)was even up to 84%at 380℃in the first 10 min.When the adsorption of SO_(3)tended to saturation,the increase of temperature has no obvious effect on the dynamic removal efficiency of SO_(3)by used sorbents.The kinetics analysis showed that the early reaction of SO_(3)adsorption by Na_(2)CO_(3)(0-40 min)conformed to the reaction-controlled shrinking core model,which is mainly dominated by the chemical reaction on the surface of Na_(2)CO_(3).Besides,the internal diffusion-controlled shrinking core model could only describe the removal of SO_(3)for the first 40 min only at 260℃.In the latter stage of adsorption(50-100 min),the surface reaction and interfacial diffusion can both describe the adsorption process,which means the internal diffusion of SO_(3)and its chemical reaction on the surface of Na_(2)CO_(3)jointly dominate the SO_(3)removal reaction.
作者
李秋白
黄亚继
许月阳
王圣
李雨欣
李金壘
魏泽坤
LI Qiubai;HUANG Yaji;XU Yueyang;WANG Sheng;LI Yuxin;LI Jinlei;WEI Zekun(State Key Laboratory of Clean and Efficient Coal-fired Power Generation and Pollution Control,Nanjing 210023,China;School of Energy and Environment,Southeast University,Nanjing 210096,China)
出处
《洁净煤技术》
CAS
CSCD
北大核心
2023年第S02期415-421,共7页
Clean Coal Technology
作者简介
李秋白(1966—),男,江苏省镇江人,高级工程师。E-mail:12013514@chnenergy.com.cn
