煤矿瓦斯等离子体活化合成甲醇反应特性及其调控方法

It is important for the methanol synthesis with high efficiency by plasma activation that quantitatively obtaining the reaction characteristics and control method for mine gas conversion to methanol. The investigation is realized by the dielectric barrier discharge respectively of gas of mine gas, mine gas/steam, mine gas/inert gas in a self-made experimental system. The exploration of the effect of gas concentration, discharge parameters, water vapor and inert gas in gas activation and methanol formation. At the same time, analysis of methanol synthesis of essential functional groups by emission spectroscopy in optical emission spectrum diagnostic techniques and changes in activity groups with the gas concentration, discharge parameters, the amount of water vapor, inert gas species and the added amount. Combined with the chromatographic analysis of CH3OH, CO, CO2 and other stable molecules, the step of controlling the reaction of methanol is determined and the reaction mechanism is revealed. Based on the collision theory, plasma characteristics and reaction mechanism, the activated methanol synthesis of multi-factor kinetic equation of mine gas plasma is constructed. And the control method to promote gas conversion and methanol generation and enhance the response of gas concentration adaptability is also proposed by coordinated optimization of discharge parameters, the amount of water vapor, the type of inert gas and the added amount of additives to control the synthesis of important active methanol groups. The research will lay a foundation for further study of the mechanism of conversion of mine gas to methanol by plasma, which is quite significant to comprehensive utilization of gas in ordinary pressure and mild conditions.

煤矿瓦斯等离子体活化合成甲醇反应特性及其调控方法的获取是瓦斯等离子体法高效合成甲醇的关键。利用自制实验系统分别对瓦斯、瓦斯/水蒸气、瓦斯/惰性气体进行介质阻挡放电，研究瓦斯浓度、放电参数、水蒸气及惰性气体对瓦斯活化及甲醇生成的影响；同时，运用发射光谱原位诊断技术解析瓦斯等离子体活化合成甲醇的关键活性基团及活性基团随瓦斯浓度、放电参数、水蒸气量、惰性气体种类及添加量的变化规律；结合CH3OH、CO、CO2等稳定分子的色谱分析结果，明确合成甲醇反应的控速步骤，揭示反应机理；基于碰撞理论、等离子体特性及反应机理，构建瓦斯等离子体活化合成甲醇的多因素动力学方程，并提出通过协同优化放电参数、水蒸气量、惰性气体种类及添加量调控合成甲醇关键活性基团的方法，促进瓦斯转化和甲醇生成，增强反应对瓦斯浓度的适应性。项目研究可为等离子体转化瓦斯制甲醇的深入研究奠定基础，对常压、温和条件下综合利用瓦斯具有重要意义。

瓦斯是蕴藏在煤层中的非常规天然气，因其主要成分甲烷是优质的气态燃料和化工原料，具有极高的利用价值。然而，我国煤矿抽采瓦斯浓度不稳定、利用率不高，大部分被排入大气中，造成了严重的环境污染和资源浪费。在国家大力推行“节能减排，低碳经济”政策的背景下，加强瓦斯综合利用十分必要。采用适当的技术手段将瓦斯制成便于运输和使用的甲醇具有重要的经济价值和社会意义。本项目针对煤矿瓦斯等离子体活化合成甲醇反应特性及其调控方法进行了研究，通过石英介质反应器、刚玉介质反应器下等离子体活化瓦斯制甲醇的实验，明晰了甲烷体积分数、水蒸气及Ar、N2等惰性气体对甲烷转化率及甲醇产率的影响规律。同时，阐明了放电电压、放电频率等放电参数对甲烷转化率及甲醇产率的影响规律。运用原子发射光谱技术对CH4-H2O、CH4-O2-N2-H2O、CH4-O2-N2-Ar-H2O等不同实验体系中的活性基团进行原位诊断，解析了 、CH•、OH•、H2、Hα等自由基及其变化规律，推断了反应物分子通过电子解离和潘宁解离产生的CHx•、H•、OH•、O•、CH3O•等自由基相互碰撞形成CH3OH的反应路径；基于低温等离子体转化瓦斯制甲醇的实验结果，设计并求解了多元非线性回归模型，揭示了对甲醇产率的影响因素强弱顺序是：放电频率>水/碳比>气体总流量>放电电压，明确了提高甲醇产率的调控方向。本项目任务书拟发表学术论文8～10篇（其中SCI/EI检索3～5篇），培养硕士研究生2～3人，培养青年学术骨干2人。目前实际已发表论文8篇（其中EI收录3篇），出版专著1部，培养硕士研究生2人，培养青年学术骨干4人（1人晋升教授职称，3人晋升副教授职称，3人被认定为黑龙江省高层次人才）。