CAJ | 학술논문

在管式炉上进行了空气燃烧及O2/CO2燃烧下美国石灰石与宜兴石灰石的煅烧后硫化实验。分析水蒸气浓度对2种燃烧方式下石灰石钙转化率的影响，并分析硫化产物的孔结构特征、表观形貌及成分。结果表明，水蒸气在石灰石硫化反应初期对钙转化率几乎无影响，在反应后期对硫化反应有显著的促进作用。水蒸气的存在促进了产物层内固态离子扩散，且使得硫化产物粒径更大。较大粒径的晶粒降低了气固扩散阻力，在反应未充分时为硫化反应提供充足的缝隙。水蒸气的存在促进了产物层的结焦现象，空位缺陷沿着晶粒边缘发生迁移，造成反应气体逆向流动，促进了硫化反应。
재관식로상진행료공기연소급O2/CO2연소하미국석회석여의흥석회석적단소후류화실험。분석수증기농도대2충연소방식하석회석개전화솔적영향，병분석류화산물적공결구특정、표관형모급성분。결과표명，수증기재석회석류화반응초기대개전화솔궤호무영향，재반응후기대류화반응유현저적촉진작용。수증기적존재촉진료산물층내고태리자확산，차사득류화산물립경경대。교대립경적정립강저료기고확산조력，재반응미충분시위류화반응제공충족적봉극。수증기적존재촉진료산물층적결초현상，공위결함연착정립변연발생천이，조성반응기체역향류동，촉진료류화반응。
A tube furnace was employed to investigate the indirect sulfation characteristics of American and Yixing limestones during air or O2/CO2 combustion. The effects of water vapor concentration on calcium conversion of the two limestone sorbents in the two combustion atmospheres were analyzed, besides, the pore structure characteristics, morphology and ingredients of the sulfation products were analyzed. Results show that the presence of water vapor has a negligible effect on calcium conversion at the initial stage of reaction, and promotes the sulfation obviously at the later stage. The presence of water vapor promotes the solid-state diffusion in the product layer, and the crystal grain size of product in a wet atmosphere is much larger. The large-size particles reduce the resistance of gas-solid diffusion and provide more reaction sites for the reactant and the sorbents before the sulfation is sufficient. Sintering of product layer is promoted in the presence of water vapor. Vacancies in the product migrate along crystal grain boundaries and through the crystal lattice, resulting in a reverse flow of mass into the pores.