O_2/H_2O燃烧方式下石灰石的间接硫化反应特性  

Indirect sulfation characteristics of limestone under O_2/H_2O combustion atmosphere

作　　者：吕晨[1] 刘小伟[1] 郭俊哲[1] 张鹏辉[1] 徐明厚[1] 

机构地区：[1]华中科技大学煤燃烧国家重点实验室,湖北武汉430074

出　　处：《化工学报》2017年第1期353-359,共7页CIESC Journal

基　　金：国家自然科学基金项目(51476064);国家重点基础研究发展计划项目(2013CB228501)~~

摘　　要：利用水平管式炉和热重实验台架,对O_2/H_2O、O_2/N_2和O_2/CO_2 3种不同燃烧方式下石灰石的间接硫化反应特性进行了研究。重点探究了燃烧方式、水蒸气浓度对石灰石间接硫化反应的影响规律与机理。同时,对硫化产物进行了X射线荧光光谱(XRF)、X射线衍射(XRD)、孔结构特性和扫描电镜(SEM)分析。结果表明,O_2/H_2O燃烧方式相比于相同氧浓度下的O_2/N_2和O_2/CO_2燃烧方式,石灰石间接硫化反应的钙转化率在化学反应控制阶段基本相同,在扩散控制阶段O_2/H_2O燃烧方式下的钙转化率有显著的提高。主要原因是水蒸气促进了硫化反应后期产物层内的固态离子扩散。此外,O_2/H_2O燃烧方式下,不同的水蒸气浓度对石灰石的钙转化率基本没有影响。A tube furnace（TF） and thermogravimetric analyzer（TGA） were used to investigate the indirect sulfation of limestone under O2/H2O combustion compared with O2/N2 and O2/CO2 combustion. It focused on the effects of combustion atmosphere and steam concentration on the calcium conversion ratio of the limestone. Besides, the sulfated products were collected for X-ray fluorescence（XRF）, X-ray powder diffraction（XRD）, pore structure characteristics and scanning electron microscopy（SEM） analysis. The results indicate that the indirect sulfation reaction has a negligible difference at the kinetically-controlled stage under different atmosphere but it is greatly enhanced at the diffusion-controlled stage under O2/H2O atmosphere compared with O2/N2 and O2/CO2 atmosphere. This is due to the fact that the presence of steam promotes the solid-state diffusion in the product layer. Besides, the calcium conversion ratio has no obvious increase when increasing the concentration of steam under O2/H2O atmosphere.

关 键 词：温室气体 二氧化碳捕集 O2/H2O燃烧 固定床 石灰石 间接硫化 SO2 

分 类 号：X511[环境科学与工程—环境工程]