以贵州六枝高硫煤为研究对象，通过热重实验对该典型高硫煤和CuO氧载体的化学链燃烧特性及其与空气直接接触时的燃烧特性加以定性分析和定量评估。为探索煤中硫的演化及其与CuO氧载体作用对CuO氧化活性的影响，进一步采用HSC Chemistry软件，分析了氧载体过量系数Φ对煤中硫分布的影响。研究表明:相比于空气下煤直接燃烧，CuO与六枝煤化学链燃烧的着火温度高，可燃指数和综合燃烧特性指数小，显示CuO氧载体更低的反应活性；在热力学平衡状态下，当0＜Φ≤1.25及Φ＞1.25时，系统中硫组分分别以固相Cu2S和气相SO2形式存在。基于上述研究结果，提出了一种煤化学链燃烧系统中同时进行脱硫和CO2捕集的新方案。

Guizhou Liuzhi high-sulfur coal (LZ) was adopted in this study,and its chemical looping combustion characteristics with CuO oxygen carrier and direct combustion characteristics with air were qualitatively analyzed and quantitatively evaluated by thermogravimetric experiments.Furthermore,the HSC Chemistry software was used to investigate the migration and evolution of sulfur species,and their interactions with CuO.The simulations were focused on the effect of the CuO oxygen excess number Φ on the sulfur distribution.The experimental results indicated that the ignition temperature of LZCuO was higher,while the flammability index and comprehensive combustion index were smaller than those of direct combustion of LZ coal under air,meaning the lower reactivity of LZ with CuO oxygen carrier than that with air.When 0＜Φ≤1.25 and Φ＞1.25,sulfur species in the system existed as solid sulfide Cu2S and gaseous SO2,respectively.Based on the results above,a new scheme was proposed to achieve simultaneous desulfurization and CO2 capture in coalfueled chemical looping combustion system.

TK16

国家自然科学基金(51776073,51276210)；河南省科技攻关项目(162102210233)