Pyrolysis of Lignin for Bio-oil under CO2 Laser Irradiation in the "Wall-Less" reactor

从生物质代表性木质素生产能量是一个有吸引力的选择，因为提供了更高的生物油产率和减少的焦炭形成。在这项提案中，将开发一种新的工艺，将木质素转化为更高质量的生物油和化学品，几乎没有二次炭化效应，这种方法称为红外激光均质热解或IR-LPHP。PI是这种方法多样化的专家，它允许在IR CO2激光器照射下在均匀的“无壁”条件下强烈进行热解实验。该方法的主要优点是，所有化学过程仅在反应器壁的冷条件下在小的“热区”中发生。CO2激光闪光热解气相中由喷雾技术产生的木质素分散颗粒，然后快速淬火许多产物，这些产物将扩散出“热区”，避免进一步的二次过程（降解、裂解或与其它分子缩合）。这种方法被强烈认为可以提高液体产物（生物油）的产率。在相同功率的激光辐照下，由于加热速率、温度和停留时间的不同，在特定的“无壁”条件下，木质素的IR-LPHP反应将产生明显不同的产物。在获得更高产量的生物油和减少焦炭形成的过程中，焦炭和反应器壁对整个过程的有害非均相影响从未得到阐明。该项目的新奇在于利用闪蒸IR LPHP技术的优点，在最小化炭-气相相互作用的“无壁”反应器中获得更多高质量的生物油。这种特殊的反应器设计允许采用一种前瞻性的探索性研究，期望打破木质素？的大分子结构，但保持建筑单元分子的芳香性。第一次在气相木质素热解中形成的中间自由基在“无壁”反应器的条件下，将直接使用低温基质隔离（LTMI）电子顺磁共振（EPR）技术进行鉴定。与布法罗大学团队合作评估关键气相反应的动力学参数，将基于CHEMKIN - 4 Pro Combustion动力学软件包建立木质素热解的全局伪一阶集总动力学模型，以预测形成芳香族所需化合物的最佳途径。 因此，该项目代表了潜在的变革性研究，因为它将提供一个独特的，非标准方法，以生产更高质量的从生物油转化为替代运输燃料和重要化学品的角度出发，研究人员提出的假设是利用激光热解在“无壁”条件下的优势，反应器将有很大的潜力，应用于各种生物质热解过程。由于生物油的几个环境优势，从结构复杂和多样的木质素材料中有效地获得大量芳烃成为一项具有挑战性但对社会有益的工作（请注意，生物油可以通过多种方式升级为生物燃料-物理，化学和催化），而不是化石燃料作为清洁燃料：CO2/GHG（温室气体）中性，无SOx排放（因为植物生物质含有微量的硫），在燃气涡轮机中NOx排放比柴油低50%以上。该项目将促进对在“无壁”反应器条件下形成生物油的新途径的理解;因此，将在生物质转化、生物燃料和生物能源方面具有广泛的应用。开发的反应动力学全局模型将有助于了解木质素热转化为高品质生物油产品的效率，该产品既可用作能源又可用作化工生产的原料，并且可以包括在纤维素、半纤维素热解以及煤炭工业的类似模型中。几乎任何形式的生物质都可以考虑用于IR-LPHP应用。因此，满足生产高质量生物油的要求的新方法在许多应用中（包括用于发电的锅炉、熔炉、发动机和涡轮机）使用生物油作为燃料油、柴油的替代品方面可能具有经济竞争力。

The energy production from a biomass representative lignin is an attractive option given that the higher bio-oil yields and decreased char formation are provided. In this proposal a novel process will be developed to convert lignin into the more high-quality bio-oil and chemicals with virtually no secondary char effect based on a method known as Infrared Laser Powered Homogeneous Pyrolysis or IR-LPHP. The PI is an expert in diversification of this method, which allows performing the pyrolysis experiments strongly in homogeneous, "wall-less" conditions under irradiation of IR CO2 laser. The principal advantage of this method is that all chemical processes occur only in a small "hot zone" practically at cold conditions of the reactor walls.The CO2 laser flash pyrolyses the lignin dispersed particles generated by a spray technique in gas phase, followed by a rapid quenching of many products which will diffuse out of the "hot zone" avoiding further secondary processes (degradation, cleavage, or condensation with other molecules). Such an approach is strongly believed to upgrade the liquid product (bio-oil) yields. Markedly different products are expected to be produced under the IR-LPHP of lignin due to the diverse heating rates, temperature, and residence times in the specific "wall-less" condition at the same power of laser irradiation.On the way to obtain higher yields bio-oil and decrease the char formation, the detrimental heterogeneous influence of the char and reactor walls on the total process has never been elucidated. The novelty of this project is to obtain more high-quality bio-oil in a "wall-less" reactor using the advantages of the flash IR LPHP technique at minimized char - gas phase interaction. This special reactor design allows employing a perspective exploratory research expecting break up lignin?s macromolecular structure, but maintaining the aromatic nature of the building block molecules. For the first time the intermediate radicals formed in the gas-phase lignin pyrolysis in the "wall-less" reactor conditions, will be identified directly using Low Temperature Matrix Isolation (LTMI) Electron Paramagnetic Resonance (EPR) technique. Collaboration with the University at Buffalo team to evaluate kinetic parameters of the key gas-phase reactions will lead to a global, pseudo-first order lumped kinetic model for lignin pyrolysis based on the CHEMKIN - 4 Pro Combustion kinetic package to predict the optimal pathways for formation of aromatic desired compounds. Therefore, this project represents potentially transformative research because it will offer a unique, non-standard approach for producing more high-quality (upgraded) bio-oil at its high yield with the perspective of transformation of bio-oil into alternative transportation fuel and the important chemicals.The hypothesis put forward by the PI lies on the idea that utilizing the advantages of laser pyrolysis in "wall-less" reactor would have a great potential for application to various biomass pyrolysis processes. Bringing high-volume aromatics efficiently from a material as structurally complex and diverse as lignin becomes a challenging but beneficial for society due to the several environmental advantages of the bio-oil (note that the bio-oil can be upgraded to the bio-fuel in a number of ways - physically, chemically and catalytically) over fossil fuels as a clean fuel as well: CO2/GHG (greenhouse gas) neutral, no SOx emissions (because the plant biomass contains insignificant amounts of sulfur), more than 50% lower NOx emissions than diesel oil in a gas turbine. This project will advance understanding of the new pathways for formation of bio-oil in "wall-less" reactor conditions; therefore, will have broad applications across biomass conversion, biofuels and bioenergy. Developed reaction-kinetic global model will help to understand the efficiency of thermal conversion of lignin into high-quality bio-oil product used both as an energy source and a feedstock for chemical production and can be included in similar models for cellulose, hemicellulose pyrolysis as well in coal industry. Virtually any form of the biomass can be considered for IR-LPHP application. Therefore, the new methodologies satisfying requirements for producing high-quality bio-oils may be economically competitive in using bio-oils as substitute for fuel oil, diesel in many applications, including boilers, furnaces, engines, and turbines for electricity generation.