“Catalytic conversion of biomass and wastes”

The use of biomass is a promising alternative to partially replace fossil resources and provide chemicals and fuels in a near future. Many thermochemical methods have been proposed so far to convert nonedible biomass, however, the adequate pathway must be carefully chosen in order to be appropriate with the biomass type and targeted products, and answer to environmental concerns and sustainability. In this period of human over-consumption, biomass wastes are more and more numerous and represent a great and variable feedstock. The use of heterogeneous catalysis should play a great role in the biomass conversion as well-chosen catalysts might bring higher selectivity and performances. In our group we undertook several type of catalytic conversion on lignin, on micro-algae residues and wastes of wood by three different catalytic routes. In this talk, we will explain our choice and the impact of the catalyst on biomass conversion. For instance, catalytic hydroconversion of lignin is a possible choice for many kinds of lignin and lead to high liquid yield. However, the selectivity is often an issue that can be partially solved by the presence of a catalyst . Hydrothermal liquefaction can provide easily algal oil from micro-algae or algal residues and the addition of a catalyst may drastically impact the rheological properties, as for instance to target a bitumen. If the targets are biofuels, the catalytic hydroconversion of algal oil must be performed with well-chosen resistant catalysts due to the presence of nitrogen and oxygenated compounds. The catalytic conversion of wood pyrolytic vapours is a relevant step to obtain a stabilized and partially deoxygenated bio-oil, however carbon must be preserved and the catalyst must have a moderate cracking activity. For all those catalytic processes, besides the design of resistant, performant and selective catalysts, a huge analytic development is always needed to follow the chemical transformations in the complex mixtures. We will present the different analytical tools used and their limit, and also, different examples of biomass (or wastes) catalytic conversion and the role of the catalyst will be discussed.