劣质重油毫秒分级气相催化裂解制备低碳烯烃的应用基础研究

The developed heavy oil millisecond grade gas phase catalytic cracking for light olefins process, coupled the inferior heavy oil microsecond alkaline catalytic pyrolysis and pyrolysis gas direct millisecond shape selective catalytic cracking process, overcomes the "caged effect" of liquid phase reaction, increases the yield and selectivity of the target olefin while producing aromatics, is a new technology for clean and high efficiency chemical processing heavy oil. However, the relevant research is still in its infancy. This project intends to analyze the reaction process and products online by means of fast pyrolysis-catalytic pyrolysis-GC/MS experimental methods, clarify the fast catalytic pyrolysis characteristics and product distribution rules of heavy oil and its group fractions, and reveal the mechanism of radical formation, polycondensation and bond cleavage during the "thermal shock" catalytic pyrolysis process, clarify the coupling mechanism of the catalytic upgrading conditions - gas phase catalytic cracking reaction conditions - the target product yield and selectivity, so as to determine the reaction pathway, catalytic mechanism and their macroscopic kinetics of inferior heavy oil millisecond grade gas phase catalytic cracking for producing light olefins. Then the 5L / h inferior heavy oil millisecond grade gas phase catalytic cracking coupled pilot plant was used to further verify the appropriate reaction conditions and product distribution rules and selectivity of the coupling process. Finally, the conversion and control theory of heavy oil millisecond grade gas phase catalytic cracking was proposed, lay the foundation for its in-depth development and application

将劣质重油毫秒碱性催化热解改质与热解油气直接气相毫秒择形催化裂解过程耦合开发的重油毫秒分级气相催化裂解制备低碳烯烃工艺，克服了液相反应“笼蔽效应”，大幅度提高目标烯烃收率和选择性的同时副产芳烃，是一项重油清洁高效化工型加工新技术。但目前相关研究尚处于起步阶段。本项目拟通过快速热解-催化裂解-气质联用仪和实验方法，在线分析反应过程与产物，明确重油及其族组分快速催化热解特性及产物分布规律，揭示“热冲击式”催化热解过程中自由基形成、缩聚与键断裂的调控机制，阐明催化改质反应条件-气相催化裂解反应条件-目标产物收率与选择性的关联耦合机制，从而确定重油分级气相催化裂解制低碳烯烃的反应路径与催化作用机制及其宏观动力学；再利用5L/h重油毫秒分级气相催化裂解耦合中试装置，进一步验证耦合工艺的适宜反应条件及其产物分布规律与选择性，提出重油毫秒分级气相催化裂解的转化调控理论，为其深度开发和推广应用奠定基础。

世界石油资源日益重质化以及汽车电动化引起的原油炼制向化工型转型升级是必然趋势。将劣质重油毫秒碱性催化热解改质与热解油气直接气相毫秒择形催化裂解过程耦合开发的重油毫秒分级气相催化裂解制备低碳烯烃工艺，能大幅度提高目标烯烃收率和选择性的同时副产芳烃，是一项重油清洁高效化工型加工新技术。本研究从减压渣油及其族组分快速热解特性、产物分布规律及其动力学、工艺的适宜反应条件及其产物分布规律与选择性等方面开展实验研究。在此基础上采用新建的5 L/h中试装置验证了劣质重油毫秒分级气相催化裂解制备低碳烯烃的工艺可行性，并提出了重油催化裂解的自由基调控机理。研究发现，减压渣油的结构参数和热敏感组分决定其高温快速热转化以及催化反应历程和机理。从饱和分、芳香分、胶质到沥青质，热解产生的焦炭逐渐增加，结焦倾向显着增加，其中饱和分的生焦率仅为0.04%，而沥青质生焦率高达30.49%。减压渣油在500-700℃的温度范围内释放的甲烷和乙烯主要来自于渣油中饱和分和芳香分的热解反应。轻芳分和中芳分热解产生的轻质芳烃明显高于其他组分。高升温速率有利于减压渣油在气相条件下热解。以中东减压渣油为原料，验证了劣质重油毫秒分级气相催化裂解制备低碳烯烃的技术可行性。该工艺的C2-C4低碳烯烃收率达到37.54 wt%、原料S的脱除率达到65 wt%。提出的自由基调控机理能够为石油脱氢催化剂以及未来的脱氢裂解制化学品技术的开发和优化指明方向。