高硫煤微波辐照过程含硫物相及官能团的吸波效应与硫变迁机制

There are some potential advantages to develop microwave irradiation desulfurization technology for clean and effective utilization of high-sulfur coal. Nevertheless, all of the research results and reports show the current desulfurization rate is not ideal and satisfying, which can not transfer and desulfurate most of the sulfur-containing impurities. The key problem is that the recognition is unclear for sulfur degradation rules of sulfur-containing compositions and some in situ chemical reactions with carbon matrix in microwave field. Therefore, in this project, the dielectric response properties of coal and some sulfur-containing compositions will be researched, as well as the effect factors of some dielectric parameters, by which the differences of selective absorption on microwave energy between coal and sulfur-containing compositions can be obtained. The polarization mechanism among coal and sulfur-containing compositions will be analyzed and concluded. Then the interaction behavior between coal and sulfur-containing minerals will be studied. In this research, we will focus on the reason appeared high temperature in micro areas around pyrite, change of ionic bond both of Fe2+ and [S-S]2-, and some in situ microwave chemical reactions of pyrite with hydrogen, oxygen and carbon monoxide bonding with carbon matrix. According the results we can establish the kinetics modeling of in situ microwave chemical reaction between sulfur-containing minerals and carbon matrix in microwave irradiation heating, which can also help to analyze and grasp the transformation mechanism of inorganic sulfur in coal. Finally, some relationships of microwave irradiation conditions and bond structures of organic sulfurs would been researched by experimental and simulation methods, analyzing the response of sulfur bond breaking and sulfur degradation rules of functional groups effected by microwave energy, and further to conclude the matching relations of irradiation conditions and organic reactions in microwave field. All of the research results obtained above can provide some theoretical knowledge and technical supports for design and optimization of microwave desulfurization process in industrial scale application.

微波辐照脱硫技术在高硫煤清洁有效利用方面具备潜在优势，然而当前的研究和报道显示该技术仍未达到理想的脱硫效果，无法实现含硫杂质的高效转化和脱除，核心问题在于对微波场下含硫组分和基团的降解规律及其与煤基质的原位微波化学反应机理的认识不清。本项目拟通过研究煤及其含硫组分的介电响应特性，分析煤及其含硫组分介电系数的影响因素，探寻其对微波响应的选择性差异，掌握煤中含硫物相及官能团的微波极化机理。研究煤中含硫物相与微波的作用行为，分析FeS2物相赋存区的局部温度与Fe-S离子键变化，以及FeS2与周围H、O、CO之间进行的原位热化学反应，建立含硫矿物与煤基质的原位微波化学反应动力学，揭示煤中无机硫的转化变迁机制。研究微波辐照条件与有机硫键合构型及稳定性的变化关系，分析煤中含硫官能团结构对微波的断键响应及硫降解规律，建立微波辐照条件与有机硫作用的匹配关系，为微波脱硫工艺设计优化提供理论依据和技术支撑。

强化高硫煤的脱硫效果对缓解世界范围内的能源需求及环境压力意义重大。研究表明，微波技术能够提升高硫煤的脱硫效率。然而，高硫煤中含硫物相及官能团的转化路径及其在微波作用下的脱硫机理尚未明晰。本项目针对煤及其含硫组分的介电响应特性、微波辐照加热过程中含硫物相的吸波效应与转变行为及含硫官能团的断键响应与硫降解机制等一系列问题开展了研究。首先采用XRD和ATR-FTIR技术研究了煤中含硫矿物和有机官能团的赋存形式；通过矢量网络分析技术获取煤样、含硫物相及含硫模型化合物的微波响应特性，并进行介电参数求解，为高硫煤的微波脱硫条件选择提供理论参考。其次，将不同微波气氛、加热温度及脱硫助剂比等条件应用于高硫煤共微波脱硫，研究高硫煤中无机硫矿物和有机硫官能团的微波辐照脱硫反应行为及转变规律，分析不同条件下煤微波脱硫转化过程中含硫组分的脱除特征，并分别采用原位热力学反应及第一性原理分析法阐释了含硫相的硫迁移反应机理；分别从煤微波加热过程温度变化、气态含硫化合物生成移除和无机硫矿物新相结构转变阐述了含硫组分对微波辐照响应的选择性差异，同时，构建了煤微波脱硫宏观响应机制与微观原子活化反应行为之间的关系，实现了含硫物相-原位热化学反应-键电信息之间的协同化表征，基于此，分析微波功率及微波时间对煤脱硫效果的影响行为，优化微波脱硫的控制参数，获取微波辐照下的最佳脱硫条件，为工业微波脱硫工艺设计优化提供技术支撑。最后，模拟微波加热条件，阐释典型含硫官能团在微波场中的断键响应及有机硫降解机制，明确了微波辐照条件与有机硫化学键合及稳定性的变化特征，深化了微波过程中含硫官能团的硫降解预判机制，为高硫煤的微波高效脱硫提供科学依据。项目共计发表学术论文20篇，其中SCI检索11篇，EI检索论文6篇，获权发明专利5项。申请者荣获重庆市科技进步奖三等奖，培养研究生5名，完成了项目计划的研究内容，达到了预期目标。