Designing catalytic pyrolysis of biomass for green hydrogen production.

该项目旨在解决设计和优化替代能源生产技术的需求，以满足到2050年的碳中和目标。本文研究的技术基于主要通过热解过程从生物质中生产氢气，即通过在高温下，在没有氧气的情况下热化学分解有机物质的过程。生物质的热解通常产生三种物质相：生物油、生物炭和热解气体。生物油是一种深棕色的液体，含有小的羰基化合物，糖基化合物和木质素基化合物，并且在提升（以降低其水分和氧含量）后具有替代传统石油燃料的潜力。生物炭是一种多孔（表面积~1400 m2/g）高含碳（C含量：65-90%）材料，由于其吸附性能，可用于过滤和有毒污染物捕获。热解气体是H2、烃类气体（C1-C4）、CO2、CO和H2S的混合物。通过改变热解工艺条件（包括反应气氛、温度、加热速率和蒸气停留时间），可以获得不同的生物油、生物炭和气态产物的产率和组成。该项目的目标是最大化气态产物流和最大浓度的氢气，这可以通过选择合适的催化剂（包括沸石基裂化催化剂）来实现。40%纤维素，28%半纤维素，20%木质素），这是一种在干旱和半干旱环境中自发生长的植物，纤维素被选为该植物的替代物，以建立对热解过程及其机制和动力学的基本理解。（i）通过反应工程建立对纤维素热解的深入了解（优化反应条件，表征产物，将底物从纤维素变为其构建片段，即葡萄糖、纤维二糖）;（ii）选择催化剂并进行纤维素的催化热解，包括条件优化以建立对催化过程的理解;（iii）研究热解气体在传统使用的Ni/Al 2 O3催化剂上经由蒸汽甲烷重整的后处理，并确定热解后气体混合物中存在的杂质对该过程的影响;（iv）对真实的生物质样品进行热解和催化热解，并比较（i）和（ii）中获得的结果。

The project aims to address the need for designing and optimizing alternative energy production technologies to meet the carbon-neutrality aims by 2050.The technology studied herein is based on production of hydrogen from biomass primarily through a pyrolysis process, i.e. through the process of thermochemical decomposition of organic matter at the elevated temperatures, in the absence of oxygen. In general, pyrolysis of biomass results in three phases of matter: bio-oil, biochar and pyrolytic gas. Bio-oil is a dark brown liquid that contains small carbonyl compounds, sugar-based compounds and lignin-based compounds, and after uplifting (to reduce its moisture and oxygen content) has a potential to replace conventional petroleum fuel. Biochar is a porous (surface area ~1400 m2/g) highly carbonaceous (C content: 65-90%) material that thanks to its adsorptive properties is used for filtration and toxic pollutant capture. Pyrolytic gases are a blend of H2, hydrocarbon gases (C1-C4), CO2, CO and H2S. By varying the pyrolysis process conditions (incl. reaction atmosphere, temperature, heating rate and vapour residence time), different yields and compositions of bio-oils, bio-chars and gaseous products can be achieved. This project targets maximisation of gaseous product stream with maximal concertation of hydrogen, and this can be potentially achieved by selecting appropriate catalysts, including zeolite based cracking catalysts.The chosen biomass feedstock is alfa plant (approx. 40% cellulose, 28% hemicellulose, 20% lignin), a spontaneously growing plant in arid and semi-arid environments, and cellulose has been selected as a proxy of this plant to build a fundamental understanding of the pyrolysis process, its mechanisms and kinetics.The project objectives are: (i) to build a robust understanding of cellulose pyrolysis through reaction engineering (optimization of reaction conditions, characterising the products, changing the substrate from cellulose to its building fragments, i.e. glucose, cellobiose); (ii) to select catalysts and perform catalytic pyrolysis of cellulose, incl. conditions optimisation to build understanding of the catalytic process; (iii) studying post processing of the pyrolytic gas via steam methane reforming on traditionally used Ni/Al2O3 catalysts and determining the effect of impurities present in the post-pyrolysis gas mixture on the process; (iv) to perform pyrolysis and catalytic pyrolysis on real biomass sample and compare the results obtained in (i) and (ii).