基于微波金属放电与介质吸波耦合强化的生物油提质机制与方法研究

As wave absorption and metal discharge are two important mechanism to strengthen microwave heating effect and promote microwave chemical reactions, a novel method for the strengthened upgrading of bio-oils was proposed based on the coupled effect of microwave metal discharge and wave absorption. However, the application of the coupled effect of metal discharge and wave absorption in the bio-oil upgrading is the cutting-edge research in the field of catalyzed cracking of bio-oils, lacking of basic research on its mechanism. In this project, the effect of microwave metal discharge and the combination of strong absorber and catalyst on the microwave cracking of bio-oils were studied separately and together with the aim to explore the detailed promotion mechanism of the metal discharge and the combination of strong absorber and catalyst on the upgrading of bio-oils, as well as their coupling mechanism in the aspects of heating effect, field effect and catalytic effect when they are co-existed. As the bio-oils are rich in water which can be used to stimulate hydrogen plasma under the microwave discharge and provide hydrogen for the cracking reaction of bio-oils, the reaction path of water under microwave metal discharge and its effect on the strengthened bio-oil conversion were also revealed. With a clear understanding of their coupling mechanism and full exploration of their superposition advantages, a new efficient microwave upgrading technology of bio-oils can be developed. The results can perfect the mechanism of microwave interacted with different medium and provide a guide for the application of strengthen microwave heating and cracking technology.

鉴于介质吸波和金属放电是强化微波热作用、促进微波化学反应的两种重要机制，本项目提出了基于微波金属放电与介质吸波耦合作用强化生物油裂解提质的构思和方法。然而，将介质吸波和金属放电耦合用于强化生物油提质的研究是生物油催化裂解领域的前沿，对其机制认知还非常欠缺。本项目拟采用由生物油代表性组分的模型化合物过渡到复杂生物油的研究路线，通过对生物油微波裂解过程中强吸波介质/催化剂和金属放电作用的剥离和叠加研究，阐明强吸波介质/催化剂和金属放电对生物油微波提质的强化促进作用机制，以及二者共同作用时在热效应、场效应和强化催化作用方面的叠加耦合机制；明确微波金属放电条件下，水蒸气作为等离子体的激发气体参与加氢反应的路径和对生物油强化转化的作用机制。研究结果不仅能促进生物油提质/精制技术的研发和发展，还能为深化认知微波场以及其它电磁场环境下不同介质的作用机制，为微波强化加热/裂解技术的拓展应用提供理论依据。

化石能源的短缺使人们日益关注可再生洁净能源和替代能源，通过直接或间接热转化的方式将生物质转化为生物燃料可降低我国对石油资源的过分依赖，环保、节能、可持续性优势显著。然而生物质直接热解液化制取的生物油品质较差，需要对其进行脱氧提质才有可能成为石油的替代燃料。本项目基于微波热作用过程的两种特性机制，金属放电和介质强化，探索生物油脱氧提质和催化转化制合成气（氢气）间接液化合成高品质生物油的新方法。通过对金属放电热效应、等离子体效应、光效应表征，发现微波诱导金属放电热效应显著，能够瞬间塑造数千摄氏度的高温热点，并伴随着等离子体形成和可见-紫外光的释放。微波金属放电热-等离子体-光催化效应的耦合释放在有机物降解和定向催化转化方面具有突出优势，有机物降解率达90%以上；通过引入水蒸气还能实现对大分子有机物的高效重整制备合成气（氢气）并有效避免积碳产生，可发展微波金属放电高效催化生物油转化制合成气（氢气）然后液化合成高品质生物油的特色技术，也可应用于生物质/煤气化过程焦油的脱除。通过对强吸波介质/催化剂组合催化生物油提质研究，发现利用微波作用SiC产生的热点效应和等离子体效应，生物油可裂解成小分子物质或基团，耦合加氢剂（甲醇、四氢萘、氢气）和催化剂的使用，可实现常压下生物油催化加氢提质，发展微波诱导生物油温和加氢脱氧提质的新技术。通过对微波金属放电和催化剂催化生物油提质耦合作用机制研究，发现微波金属辅助生物质热解，可催化水碳反应制氢和生物油原位加氢脱氧反应，实现生物油的部分脱氧提质，耦合HZSM-5催化剂二次催化提质，可实现生物油的深度脱氧提质，发展基于微波金属放电和催化剂协同作用的生物质催化转化制备高品质生物油技术。本项目研究结果不仅能促进生物油提质/精制技术的发展，还能为微波强化加热/裂解/催化转化技术的拓展应用提供理论依据。