Microwave-assisted transformations of agroresources: an example of green chemistry

Faced with the inevitable depletion of fossil resources, agricultural productions have rapidly emerged as a promising renewable alternative. Alongside its traditional involvement in the agro-food, the biomass has nowadays opened new vistas in the non-food sector. Indeed, original products and structures, potentially biodegradable, are proposed as substitutes for conventional petrochemical derivatives. The steady rise of oil prices, on the one hand, and the implementation of a new European legislation (REACH: Registration, Evaluation and Authorization of Chemicals), on the other hand, have only help to boost the academic and industrial research in this area. In this context, microwave-mediated synthesis has progressively emerged as a green chemistry technology. Application of microwaves (MW) as a non conventional heating source finds a plethora of illustrations in the field of organic synthesis. Microwaves usually accelerate chemical processes, while offering improved yields and selectivities. MW heating enables reactions under solventless conditions, providing unique chemical pathways, with special advantages such as ease of manipulation and reduction (or
prevention) of pollution "at source".
Various reactions and processes can be applied to transform lignocellulosic raw materials into valuable fuels and chemicals. Selected examples of strategical modifications of renewable biomass feedstocks via activation by microwave irradiation are proposed herein.