Solar Biomass Gasification Combined With Iron Oxide Reduction for Syngas Production and Green Iron Metallurgy

International audienceThe solar gasification of biomass with iron oxide for combined syngas and iron production was investigated. Both solar energy and biomass are promising renewable energies. The process of gasification converts solid carbonaceous feedstocks into either fuels or chemicals. However, conventional processes require partial combustion of the feedstock for energy supply and inherently suffer from high oxygen production costs and low syngas calorific value due to dilution with combustion products. Chemical looping gasification using solid oxides is an alternative option to tackle these issues. By supplying concentrated solar energy as the high-temperature heat source, it is possible to produce even more syngas from the process while enabling solar energy storage into dispatchable fuels. This work proposes to explore solar biomass gasification over iron oxide at high heating rates, representative of the conditions obtained in solar reactors. Thermodynamic equilibriums of gasification reactions between 100 and 1,500 • C were calculated and experimental results obtained at 1,100 • C with a specially designed induction furnace were reported for biomass gasification with iron oxide, water, or carbon dioxide as oxidizing agents. Solid products analysis showed that iron oxide can be reduced to metallic iron depending on the proportion of the oxygen carrier. These results indicate that iron oxide is an effective material for solar biomass gasification producing both syngas and iron via a novel green metallurgical process

Pyrolyse à haute température de particules de bois centimétriques

National audienc

Pyrolysis of centimetre-scale wood particles: New experimental developments and results

International audienceThis work is devoted to the pyrolysis of centimetre-scale wood particles, for temperature ranging between 450 and 1050 degrees C. A specific device has been designed to perform pyrolysis tests on a single particle and to collect both thermal and chemical data which are necessary to describe pyrolysis at centimetre-scale. Temperature profiles inside the sample are monitored during pyrolysis. Char, gas, tars and water yields, as well as the elemental composition of each class of products are measured. The yields of the main gaseous species (CO, CO2, CH4, C2H4 and H-2) are monitored during the reaction. Tars are collected, and six compounds are quantified

Solar Biomass Gasification in Presence of Metal Oxide

International audienc

Solar Biomass Gasification in presence of iron oxide

International audienc

Experimental study on fast pyrolysis of free-falling millimetric biomass particles between 800 degrees °C and 1000 degrees °C

International audiencePyrolysis experiments were performed between 800 degrees °C and 950 degrees °C on wood particles with diameters from 350 to 800 $\mu$m in a lab-scale drop tube reactor to reproduce surface heat flux representative of gasifiers conditions. It was shown that particle size affected the required pyrolysis time but changed neither gas/tar/char mass yields nor composition of the products at the end of pyrolysis. The initial particle size also affected the resulting char morphology: the larger the biomass particles, the more fibrous the char. Temperature had influence neither on gas/tar/char mass yields nor on gas and solid elemental composition at the end of pyrolysis, but significantly changed the yields of individual gas species. Whatever the conditions tested, a significant shrinkage could be observed on particles during pyrolysis. These experimental results confirm the strong coupling between chemical reactions, particle geometrical properties and heat transfers during pyrolysis under these conditions

Hydrogen production from solar-driven biomass gasification in a high-temperature continuously-fed solar reactor

International audienc

Volatile species release during torrefaction of wood and its macromolecular constituents: Part 1-Experimental study

International audienceTorrefaction tests were carried out in a thermobalance and in a lab-scale device on beechwood and on its constituents cellulose, lignin and xylan. The main volatile species measured were water, formaldehyde, acetic acid and carbon dioxide. Thanks to measurement before volatiles condensation, the yield of formaldehyde was shown to be higher than usually observed in literature. Smaller amounts of methanol, carbon monoxide, formic acid and furfural were also quantified. Each constituent did not produce all species. Beech torrefaction could be described by the summative contribution of its three constituents up to 250 degrees C. At 280 degrees C and 300 degrees C, tests performed with constituents mixtures showed that there were interactions between cellulose and the two other constituents. A hypothetical mechanism was proposed to explain these interactions. (C) 2014 Elsevier Ltd. All rights reserved