石油焦和煤的共气化协同作用机理及动力学研究

With the increasing demand and densification of petroleum, both the output of petcoke and its sulfur content have increased. How to utilize petcoke in a high efficiency and clean way becomes an urgent problem to be solved for petrochemical industry. The gasification technology is an effective way for the resourcable utilization of petcoke, but the gasification reactivity of petcoke is much low. In our previous study, it is found that the low reactivity of petcoke can be improved by co-gasified with coal. Unfortunately, the co-gasification reaction mechanism remains unclear, coupled with the lack of the universal kinetic model, the development of the petcoke gasification was severely hampered. In this application, the co-gasification synergistic reaction mechanism and kinetic of petcoke with coal will be studied by using the tube furnace and thermogravimetric analysis. The effect of organic/mineral matter on co-gasification will be clarified with the decoupling method and the constitution of coal. In order to reveal the co-gasification synergistic reaction mechanism, the effect of organic/mineral matter on the carbon structure of petcoke will be investigated. The catalytic effect of mineral matter in coal on the reaction of petcoke with gasifying agent will also be quantified in the view of gas-solid reaction mechanism. Based on our previous Boltzmann model and the co-gasification behavior, the universal kinetic model for co-gasification of petcoke with coals will be established. Results of this application will provide theoretical guidance for coal selection and gasifier design/operation for co-gasification of petcoke with coal.

随着石油需求量的增加及其重质化程度的加剧，石油焦产量及其硫含量都在增加，清洁高效的利用石油焦迫在眉睫。气化技术作为石油焦资源化利用的有效途径，其难题之一是石油焦的气化活性太低。申请人前期研究发现石油焦的低气化活性可通过与煤共气化得到改善。但石油焦和煤的共气化反应机理尚不清楚，加上普适性动力学模型的缺乏，严重阻碍了石油焦气化技术的发展。本申请拟利用管式炉和热重仪对石油焦和煤的共气化协同作用机理和动力学进行研究。采用解耦的方法，结合煤的组成特征，探究煤中有机质和无机质对石油焦气化活性的影响；从气-固反应机理着手，考察两类组分对石油焦主体碳结构的影响，量化煤中无机质对石油焦与气化剂反应的催化作用，揭示共气化的协同作用机制；基于前期构建的玻尔兹曼动力学模型，结合石油焦与煤的共气化特征，构建普适性的共气化动力学模型。本研究对石油焦共气化原料的选取、气化炉的设计和操作具有理论指导意义。

石油焦的清洁高效利用是石油化工行业亟待解决的重要问题之一。气化技术作为石油焦资源化利用的有效途径，其难题之一是石油焦的气化活性太低。石油焦与煤共气化可明显改善石油焦的气化反应性。针对石油焦和煤共气化过程中存在的问题，本项目主要对石油焦和煤共气化过程中的协同作用机理进行了探索，并分析了共气化的动力学特征。通过研究多种石油焦和煤的气化反应特性及其理化性质，全面认识了石油焦和煤气化反应性的差异及影响因素，石油焦的低气化反应性主要归因于其自身的碳结构特征和组成。通过对石油焦和煤共气化的研究，清楚了石油焦和煤的混合方式、煤中各组分及不同矿物质等对石油焦低气化反应性的影响；明确了共气化反应性主要受煤中矿物质种类的影响，其中富含铁钙等组分的煤、煤焦、煤灰和模拟煤灰均可明显改善石油焦的低气化反应性，从而揭示了石油焦和煤共气化过程中的协同作用机理。通过对比研究石油焦和煤的共气化动力学特征及石油焦气化的内在机理，借助概率统计概念，构建了适用于石油焦气化和共气化的动力学模型；与常用煤气化动力学模型相比，该模型能更好的拟合石油焦的气化过程，模拟得到的动力学数据较为准确。通过本项目的研究，不仅为石油焦和煤的气化利用提供了有价值的基础数据，更为石油焦和煤共气化原料的选取、共气化过程的模拟和气化炉的设计提供了科学依据和理论指导。