基于产物结构分析的生物质/煤高温干馏过程耦合作用机制研究

The partial substitution of coking coals by biomass during coking process is one of the most effective methods of reducing coking coal consumption and CO2 emissions. However, the interaction mechanism and its effects on coke quality during biomass/coal co-carbonization are unclear. Meanwhile, the addition amount of biomass into the coking coal is limited. In this project, glucose is used as biomass model compound to study the interaction mechanism. The methods of isotope tracer coupled with nuclear magnetic resonance (NMR) spectroscopy analysis are applied to characteristic the structural parameters and element species of coking products, and then the carbon physical effect, hydrogen and oxygen transfer effect are discovered. Meanwhile, the influences of alkali metal and biomass component on the formation and evolution of coking products are also considered. Thus, the interaction mechanism during biomass/coal co-carbonization is understood. Based on the coal blending theory, biomass pretreatment and the modification of coking coal by pitch are proposed to rebuild the coal maceral’s balance, and then the variation of the maceral’s structure and its effects on coke quality are also discussed. Hence, the key parameter of influencing coke quality during biomass/coal co-carbonization is found. The study will provide a theoretical guideline for the widely application of biomass/coking coal co-carbonization.

生物质替代部分炼焦煤制备冶金焦是钢铁行业减少炼焦煤消耗和CO2排放的有效方法之一。目前国内外对生物质/炼焦煤高温干馏过程耦合作用及调控焦炭质量的机制还缺乏深入认识，同时炼焦煤中生物质掺混量受限的问题有待解决。本研究用葡萄糖作为生物质模型化合物，采用同位素示踪与核磁共振波谱（NMR）分析生物质模型化合物/炼焦煤高温干馏产物的结构参数和元素形态，获得碳的物理效应、氢和氧的传质效应，掌握生物质典型组分及碱金属对炼焦煤高温干馏产物的形成与演变的影响，揭示生物质/炼焦煤高温干馏过程耦合作用机制；利用煤沥青调质和生物质预处理等方法重建生物质/炼焦煤的“煤岩组分平衡”，研究高温干馏过程中煤岩组分的结构变化对焦炭质量的影响，阐明生物质/炼焦煤高温干馏过程调控焦炭质量的机制，为生物质/炼焦煤高温干馏制备冶金焦的推广应用夯实理论基础。

生物质替代部分炼焦煤制备冶金焦是钢铁行业减少炼焦煤消耗和CO2排放的有效方法之一。目前国内外对生物质/炼焦煤高温干馏过程耦合作用及调控焦炭质量的机制还缺乏深入认识，同时炼焦煤中生物质掺混量受限的问题有待解决。项目采用热重-质谱联用仪（TG-MS）研究了生物质/炼焦煤干馏过程的动力学和气态产物的析出特性，获得了生物质/炼焦煤高温干馏过程中碳的物理效应、氢传质效应、碱金属的催化效应的影响；借助In-situ FTIR-MS和FTIR-ATR等分析技术研究生物质/炼焦煤高温干馏过程中产物表面官能团形态与分布随着反应温度的变化规律，结合半焦和焦炭物理化学结构表征，获得了生物质对炼焦煤高温干馏过程中产物形成与演变的影响规律，进而揭示了生物质/炼焦煤高温干馏过程的耦合作用机制。采用生物质部分替代气煤/炼焦配合煤重新建立生物质/炼焦煤的“煤岩组分平衡”，在固定床反应器上进行生物质/煤高温干馏实验，通过对焦炭抗压强度及反应性与反应后强度等焦炭质量评价，并对半焦和焦炭进行FTIR,XPS,NMR,SEM和OP等表征，获得了生物质对炼焦煤高温干馏过程中产物形成与演变的影响规律；此外，发现木屑代替气煤炼焦可以将配合煤中木屑掺入量从5%提高到15%。在40kg实验焦炉和6m工业焦炉上进行了炼焦煤高温干馏制备冶金焦的实验，分析了焦炭的质量指标，获得了水分及挥发分对焦炭质量的影响规律；同传统技术相比，优化配煤后配合煤挥发份从28.3%提高至31.7%，且焦炭CRS和CRI值分别由62.2%和27.3%提高至67.1%和23.4%，实现了优化配煤定向调控焦炭质量的目标。项目组共发表期刊论文22篇，其中SCI论文9篇，EI论文3篇，申请国家发明专利1件；参加工程热物理年会4人次，其中作口头报告1次，培养毕业硕士研究生4名。