The NO reducibility of semi-coke has attracted ever-increasing attention. While little previous work focused on the difference between pyrolyzed and gasified semi-cokes on NO reduction. The co-reduction of pyrolyzed and gasified semi-cokes toward NO deserves specific research to optimize the use of the low-volatile carbon-based fuels. This study focused on NO reduction by the pyrolyzed semi-coke, gasified semi-coke and their respective ash free cokes through a laboratory-scale quartz reactor. Experimental results indicated that the yield of CO2 peaked between 800 °C and 850 °C. The high conversion of CO to CO2 represented strong reaction between NO and semi-coke in NO heterogeneous reduction. The comparison of ash free cokes and their original semi-cokes demonstrated that minerals of semi-coke mainly contributed to the NO reduction below 800 °C. The kinetic analysis revealed that the apparent activation energy of blended semi-cokes increased almost linearly with the decline of pyrolyzed semi-coke fraction. The larger specific surface area benefited the NO diffusion and the adsorption capacity, which lowered the apparent activation energy in the kinetic control zone. Besides, the mixture comprised of 75% pyrolyzed and 25% gasified semi-coke showed a superior NO reduction ratio compared with pyrolyzed semi-coke beyond 750 °C.

中文翻译：

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热解气化半焦混合还原NO非均相实验及动力学研究

半焦的NO还原性越来越受到关注。虽然之前的工作很少关注热解半焦和气化半焦在 NO 还原方面的差异。热解和气化半焦向 NO 的共同还原值得特别研究以优化低挥发性碳基燃料的使用。这项研究的重点是通过实验室规模的石英反应器热解半焦、气化半焦和它们各自的无灰焦对 NO 的还原。实验结果表明，CO2 的产率在 800 °C 和 850 °C 之间达到峰值。CO 转化为 CO2 的高转化率代表 NO 异相还原中 NO 与半焦之间的强烈反应。无灰焦与原半焦的比较表明，半焦的矿物质主要是在 800 ℃以下对 NO 的还原做出贡献。动力学分析表明，混合半焦的表观活化能随着热解半焦分数的下降几乎呈线性增加。较大的比表面积有利于 NO 的扩散和吸附能力，从而降低了动力学控制区的表观活化能。此外，与超过 750 °C 的热解半焦相比，由 75% 热解半焦和 25% 气化半焦组成的混合物显示出更高的 NO 还原率。