Designing catalytic pyrolysis of biomass for green hydrogen production.

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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).