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International audience; The aim of the present work is to simulate the segregation and interaction between the two kinds of particles involved. Thesimulation is made using the Discrete Elements Method (Ref 1) implemented in the Open Software LIGGGHTS (Ref 2). The wood chips are represented using either a multisphere approximation or a single sphere model. In both approximations, the model particles have the same volume and the same dynamic properties as the wood chips.The following differences differences between the two approximations are observed:- The transient behaviour of mixing is slower with the single sphere approximation than with the multisphere one. Differences are specially notable at low rotation speed.- The multisphere approximations shows that the orientation of the wood chips is approximately anisotropic except near the walls or the baffles- At given values of the number of steel balls and wood chips and of the rotating speed, the average porosity of the bed is smaller with the multisphere approximation than with the single sphere one.With both approximations, the final (stationary) value of the segregation index is independent of the rotating speed (in therange investigated); however, the values of this final segregation index is slightly larger with the single sphere model.This kind of simulations can be extended to the investigation of heat transfer between the two kinds of particles and to thefragmentation of the wood particles.

LORVER project: production chain of biomass for industrial purposes from former sites and materials. . Contaminated Site Management in Europe (CSME) & Sustainable Approaches to Remediation of Contaminated Land in Europe (SARCLE)

International audience; The talk will give an overview of current research developed at CNRS-LRGP 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 methodology is developed ranging from molecular to bioenergy chain 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 some examples: 1. At the mesoscopic and particle scales, the mechanism of biomass pyrolysis are studied by "slow" conventional setups (TGA, DSC) & by original "fast" setups (image furnace [1], micro fluidized bed). The extent of softening during biomass pyrolysis and interactions in the polymer network are revealed by in-situ analyses: NMR and rheology [2]. Advanced mass spectrometry is also used to analyse tar with Pr. F. Qi's group (Hefei) [3]. 2. At the reactor scale, a 3 kg/h pilot plant has been constructed to study fluidized bed pyrolysis or gasification (syngas quality, but also bed agglomeration). 3. At the process scale, models of thermochemical processes are developed under Aspen Plus [4]. Detailed mass and energy balances are obtained including pollutant emissions (trace species such as tar, NOx, minerals, etc.). The effect of catalysts and reactor operating conditions are modelled [5]. These models point out the key process units and parameters detrimental to the energy and environmental efficiency. References [1] Christodoulou M., Mauviel G., Lédé J,(...), Billaud F., Novel vertical image furnace for fast pyrolysis studies, Journal of Analytical and Applied Pyrolysis (2013), vol. 103, p. 255-260 [2] Dufour, A., Castro-Diaz, M., (...) Snape, C., In situ analysis of biomass pyrolysis by high temperature rheology in relations with 1H NMR, Energy Fuels 26 (10), 6432-6441, 2012. [3] Dufour, A., (...) Billaud F., Mauviel, G., Qi, F. Revealing the chemistry of biomass pyrolysis by means of tunable synchrotron photoionisation - mass spectrometry, RSC Advances 3(14), 4786-4792, 2013. [4] Abdelouahed, L., Authier, O., Mauviel, G., (...) Dufour, A., Detailed modeling of biomass gasification in dual fluidized bed reactors under Aspen Plus, Energy Fuels 26 (6), 3840-3855, 2012. [5] Olcese, R.N., Francois, J., Bettahar, M.M., Petitjean, D., Dufour, A., Hydrodeoxygenation of guaiacol, a surrogate of lignin pyrolysis vapors, over iron based catalysts: Kinetics and modeling of the lignin to aromatics integrated process, Energy Fuels 27(2), 975-984, 2013.

International audience; The talk will give an overview of current research developed at CNRS-LRGP 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.

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.

International audience; An original gas-liquid contacting system is proposed, consisting of a pump, an orifice, a vertical tube coaxial to the orifice and an impinging plate. The pump generates a downward vertical liquid jet through the orifice situated above the gas-liquid dispersion level. The two phase jet is directed towards an impinging plate near the bottom of the tank and dispersed in the volume of the liquid. Liquid is withdrawn below the impinging plate and recycled. This reactor may be used for gas-liquid reactions (ie hydrogenations) and also to mix liquids, to disperse particles, to oxygenate waste water etc.... Performances and design rules of this equipment are proposed. Then, the results are compared to performances of bubble columns, stirred tanks, and other academic and industrial jet systems. It is shown that, at a given energy dissipation, this system yields much higher mass transfer densities than a classical stirred tank provided with a Rushton turbine. Finally some suggestions about mass transfer mechanisms and efficiency of dissipated power are given.

International audience