【摘要】 【目的】燃煤电厂是中国最主要的人为汞排放源，利用廉价高碳生物质原料制备碳基脱汞吸附剂成为研究热点。【方法】本文以木屑为原料，利用熔盐热解一步碳化和活化制备多孔碳，利用扫描电子显微镜、X射线光电子能谱（X-ray photoelectron,XPS）和比表面积分析测试研究了多孔碳的微观结构和表面化学特性，在固定床实验平台上测试了多孔碳的烟气脱汞性能，通过程序升温脱附实验和XPS表征识别了多孔碳上汞的吸附产物，以揭示多孔碳对Hg⁰的吸附机理；运用Aspen Plus对热解过程进行仿真模拟，为建立生物质熔盐热解产碳工艺提供基础数据。【结果】熔盐多孔碳上具有大孔-介孔-微孔骨架，其表面具有丰富的含氧官能团，在50～150℃温度区间内表现出良好脱汞性能；在LiCl-KCl熔盐体系中添加Fe（NO₃）₃可显著提高多孔碳的脱汞性能，脱汞效率达90%以上；多孔碳表面丰富的C==O基团将气态Hg⁰氧化并进一步转化为有机结合汞（Hg-OM）固定，同时C==O还原为C—O。熔盐可循环使用3次以上，且循环后制备的多孔碳仍保持高效脱汞性能。Aspen Plus模拟表明，木屑在700℃热解时碳产率约为31%，与实验结果吻合。【结论】熔盐热解工艺可实现生物质的同步碳化和活化，获得的多孔碳具有优异的烟气脱汞性能，为燃煤烟气汞污染治理提供了新思路。更多还原

【Abstract】 [Objective] Coal-fired power plants are one of the largest mercury emission sources. The development of carbon-based mercury adsorbents by using low-cost biomass materials with high carbon content has become a research hotspot. [Methods] This study utilizes molten salt pyrolysis to realize one-step carbonization and activation of wood chips to produce porous carbon materials. Scanning electron microscopy, Bruneian-EmmettTeller and X-ray photoelectron spectroscopy（XPS） was adopted to determine the microstructure and surface chemistry of as-prepared porous carbon. Programmed temperature desorption experiment was conducted to identify the mercury adsorption products, and the involved mechanism for Hg⁰ adsorption on porous carbon was excluded. The pyrolysis process was simulated by Aspen Plus to provide basis results for building molten salten pyrolysis technology.[Results] Molten salt porous carbon has a macroporous-mesoporous-microporous skeleton, and its surface has abundant oxygen-containing functional groups, showing good mercury removal performance in the temperature range of 50-150 ℃. The addition of Fe（NO₃）₃ in LiCl-KCl molten salt system can significantly improve the mercury removal performance of porous carbon, and the mercury removal efficiency is more than 90%. The abundant C== O groups on the surface of porous carbon oxidize gaseous Hg⁰ and further convert it into organically bound mercury（Hg-OM）, while C== O is reduced to C—O. The molten salt can be recycled more than three times, and the porous carbon prepared after the cycle still maintains high mercury removal performance. Aspen Plus simulation shows that the carbon yield of sawdust pyrolysis at 700 ℃ is about 31%, which is consistent with the experimental results. [Conclusion] An one-step pyrolysis and activation strategy within molten salt system was developed to prepare porous carbon, which exhibited superior mercury adsorption performance from coal-fired flue gases. This work provided a new idea for mercury abatement from coal-fired power plants.更多还原