基于组分交互耦合效应下大型海藻与陆生生物质共催化热解的基础研究

Abundant marine algae resources are an important supplement for terrestrial biomass. At present, the pyrolysis technology of biomass for bio-oil has become a hot topic in the research of biomass. Macroalgae and terrestrial biomass are able to complement each other through co-pyrolysis, bring synergistic coupling effect into play, reduce energy consumption, and improve the quality of bio-oil. Meanwhile, catalytic pyrolysis can also be applied to macroalgae and terrestrial biomass. As it is the components which act as the core of the synergistic effects caused by co-pyrolysis, an innovative idea of co-catalytic pyrolysis of macroalgae and terrestrial biomass based on interaction coupling effects of components was brought forward in this project. Macroscopic pyrolysis experiments mathematical model analysis and forecast, quantum chemistry calculation based on the molecular level and other multi-scale, multi-methods were combined and firstly adopted in studying the interaction coupling co-pyrsolysis mechanism of components, the influential factors of co-pyrolysis, and other important basic issues. Based on the formation of small molecular gases, acids, ketone, hydrocarbon, co-pyrolysis mechanism influenced by participating components were investigated through experiments such as TG, Py-GC-MS, etc. Properties of oil, gas, and char products produced during pyrolysis were studied through experiments such as fixed bed fast pyrolysis. Pathways and reaction mechanisms of how the components converted into oil through exchange coupling and co-pyrolysis were further revealed. Therefore, the laws and predicting models of co-pyrolysis for bio-oil based on multicomponent contents were further studied. Finally, seaweed and terrestrial biomass were selected and mixed for the co-catalytic pyrolysis experiments on multi-platform, regulations and mechanisms of co-catalytic pyrolysis for bio-oil with different microporous and mesoporous catalyst ratios were revealed. The optimal characteristics of bio-oil derived from the co-catalytic pyrolysis would be analyzed. This project is able to provide theoretical and technical basis for improving the pyrolysis utilization level of macroalgae and terrestrial biomass.

丰富的海藻资源是陆生生物质的重要补充。目前热解液化技术已成为生物质能转化利用研究的热点，对大型海藻与陆生生物质采用共热解可发挥协同效应，减少能量消耗，提高热解油品质。同时催化热解技术对大型海藻及陆生生物质热解油提质提产也行之有效。鉴于共热解产生协同作用的核心是各组分，故本项目创新性地提出基于组分交互耦合效应下，研究大型海藻与陆生生物质共催化热解的新思路。采用宏观热解实验、数学模型分析预测、基于分子层面量化计算等多手段、多尺度相结合，率先对大型海藻与陆生生物质各组分交互耦合共热解机理、共热解制油影响因素等重要基础问题展开研究。基于小分子气体及酸、酮、烃、醇类产物生成，通过热重、Py-GC-MS等研究各组分参与共热解机理；通过固定床快速热解等实验研究生成油、气、炭特性，阐释各组分交互耦合共热解成油转化途径与反应机制，进而掌握基于多组分含量的共热解制油规律与预测模型。最终优选大型海藻与陆生生物质组合在多实验平台上进行共催化热解研究，揭示不同微孔与介孔分子筛配比作用下催化热解制油规律与机制，分析最佳共催化热解产油特性。本项目可为提高大型海藻与陆生生物质热解利用水平提供理论和技术基础。

本项目基于大型海藻与陆上生物质组分间的协同耦合作用，采用热失重分析，Py-GC/MS分析，固定床快速热解及流化床快速热解等实验，分子层面量化（DFT）计算等多手段对大型海藻与陆生生物质共热解及制油机理进行了研究，明确了原料组分、温度、升温速率等关键因素对热解制油的影响机制，掌握了基于多组分特征与含量的共热解制油规律。研究表明共热解时一物料组分对另一物料具有影响作用，如条浒苔和纤维素共热解时生物油中的脱水糖比例增加，羧酸含量减少。而半纤维素的添加影响了液体产物的分布，半纤维素与条浒苔热解中间组分发生了相互作用，促进了脱水，脱羰和脱羧反应等反应的正向发生。木质素的参与共热解降低了条浒苔中呋喃类物质的产量。组分间作用也较明显，海藻多糖与纤维素共热解生物油中的酮类和醛类物质明显增加，酸类和含氮类物质明显降低。海藻焦与稻壳挥发分及海藻挥发分与稻壳焦之间的交互反应也印证了海藻与陆生生物质之间的协同作用，交互反应对呋喃和苯酚的增加以及糖类的急剧减少发挥着重要作用。海藻与稻壳共热解产生的协同作用不仅稳定了热解过程，提高了热解转化率，还降低了生物油中的酸类及含氮类组分含量，并在此基础上构建了海藻生物质与陆生生物质的共热解制油预测模型。同时优选大型海藻与陆生生物质进行微孔（ZSM-5）与介孔分子筛（MCM-41）不同比例混合共催化热解制油，最终获得最佳共催化热解产油特性，揭示了海藻与稻壳共催化热解提质规律与机理，并对海藻生物质的高值化利用提供了借鉴与参考意义。