A multiscale approach to optimise the thermochemical conversion of lignocellulosic biomass

International audience; This poster gives an overview of current research developed at CNRS Nancy (France) on the thermochemical conversion of lignocellulosic biomass. The main studied processes are pyrolysis and gasification to produce electricity, biofuels intermediates or value-added chemicals such as aromatics. A multiscale approach is developed ranging from molecular to process scales. The studies at molecular and mesoscopic levels give insight into the mechanisms of biomass pyrolysis and are used to design reactors. Conversely, the detailed mass and energy balances of processes point out process units with low energy efficiency and/or high environmental impact and stress the improvement of reactors and the need of more fundamental knowledge. The methodology will be highlighted by examples at: 1. the molecular scale: advanced NMR studies are used for understanding primary pyrolysis of biomass. Tar are analysed by photo-ionisation mass spectrometry and tar cracking kinetics are studied. 2. the mesoscopic and particle scales: the mechanism of biomass pyrolysis are studied by in-situ rheology and H NMR. Heat and mass transfers inside biomass particles are studied by specific devices with an imposed heat flux density (W/m2) [1]. 3. the reactor scale: Fluidised bed or cyclone are designed and home built in the lab. Advanced reactor models are developed and handled hydrodynamic, transfers and chemical kinetics. 4. the process scale: Bioenergy chains are modelled under Aspen Plus [2] to provide advanced life cycle inventory: from forest growth to end products. [1] JAAP 103, 255-260, 2013. [2] Energy & Fuels 27 (12), 7398-7412, 2013.