@article {1875, title = { Hydrothermal conversion of wood, organosolv, and chlorite pulps }, journal = { BIOMASS CONVERSION AND BIOREFINERY }, volume = {10}, year = {2020}, pages = {1-13}, abstract = {

In this work, beech wood has been submitted to fractionation and hydrothermal liquefaction in order to produce fermentable carbohydrates. Fractionation either by ethanol organosolv or by sodium chlorite/acetic acid (SC/AA) treatment allowed obtaining delignification yields of 50 and 91 wt.\% respectively. The recovered pulps were then submitted to liquefaction in hot-compressed water (HCW). Three temperatures were studied: 180, 200, and 220 degrees C during 2 h. The same experiments were conducted on untreated beech and model cellulose (Avicel PH-101). Product yields and total carbohydrates were determined. The liquefaction products, i.e., solid residue, water-soluble compounds, and permanent gas, were analyzed respectively by X-ray diffraction (XRD), high-performance anion-exchange chromatography with pulsed amperometric detector (HPAEC-PAD), and gas chromatography (GC). SC/AA treatment allowed a high recovery of hemicelluloses and for this reason, xylose content was significantly higher than for the organosolv pulp. The maximum yields of total carbohydrates (based on the initial carbohydrates in wood), found when the liquefaction temperature was 220 degrees C, increased from 9.0 wt.\% for the raw beech to 13.5 and 33.7 wt.\% for the organosolv and SC/AA pulps respectively.

}, url = {https://hal.univ-lorraine.fr/hal-02125963}, author = {F. BUENDIA-KANDIA and N. BROSSE and D. PETITJEAN and G. MAUVIEL and E. RONDAGS and E. GUEDON and A. DUFOUR} } @article {1829, title = { Effect of combustion technology and biogenic CO2 impact factor on global warming potential of wood-to-heat chains }, journal = { APPLIED ENERGY }, volume = {235}, year = {2019}, pages = {1381-1388}, abstract = {

In this work wood-to-heat chains are assessed on environmental and micro-economical aspects. Wood combustion produced various minor pollutants, which should be considered in life cycle assessment For this purpose different wood combustion processes have been modeled under Aspen Plus (R) software in order to assess pollutant emissions (CO2, aromatic compounds, CO, etc.) based on industrial emission data and therefore to obtain a rigorous life cycle inventory. Different technologies are assessed for a fixed heating demand and hot water production of a typical French house: district heating fueled by wood chips, individual stoves or boilers fueled by wood logs or pellets. Electricity, natural gas, and fuel oil solutions complete the scenario set. The different heating solutions are compared in terms of their greenhouse gas emissions and of the cost of the final energy (including investment and operating costs). The important effect of minor pollutants (such as CO and volatile organic compounds) on the global warming potential of wood-to-heat chains is highlighted. The performance of wood scenarios compared to fossil-based ones is also highly dependent on the impact factor assumed for the biogenic CO2. The wood-based scenarios present a wide range of costs with pellet solutions being more expensive on investment and pellet production.

}, url = {https://hal.univ-lorraine.fr/hal-01935854}, author = {C. PELLETIER and Y. ROGAUME and L. DIECKHOFF and G. BARDEAU and M.N. PONS and A. DUFOUR} } @article {1841, title = { Lignin-Based Carbon Nanofibers as Electrodes for Vanadium Redox Couple Electrochemistry }, journal = {NANOMATERIALS}, volume = {9}, year = {2019}, abstract = {

Three different types of lignin (kraft, organosolv and phosphoric acid lignin) were characterized and tested as precursors of electrospun nanofibers. Polyethylene oxide (PEO) was added as a plasticizer and dimethyl formamide (DMF) employed as a solvent. It was found that the molecular weight of lignin was the key parameter to understand the differences of the mechanical stability of the resultant fiber mats. In the case of kraft lignin (KL), the influence of some changes in the synthetic process was also tested: applied voltage, pretreatment in air or not, and the addition of a small amount of Ketjen black. After pyrolysis in nitrogen flow, the obtained carbon nanofibers (CNFs) were characterized by different techniques to analyze their differences in morphology and surface chemistry. Vanadium electrochemistry in 3M sulfuric acid was used to evaluate the different CNFs. All fibers allowed electrochemical reactions, but we observed that the oxidation of V(II) to V(III) was very sensitive to the nature of the raw material. Materials prepared from kraft and phosphorus lignin showed the best performances. Nevertheless, when 1 wt.\% of Ketjen black was added to KL during the electrospinning, the electrochemical performance of the sample was significantly improved and all targeted reactions for an all-vanadium redox flow battery were observed. Therefore, in this work, we demonstrated that CNFs obtained by the electrospinning of lignin can be employed as electrodes for vanadium electrochemistry, and their properties can be tuned to improve their electrochemical properties.

}, url = {https://hal.univ-lorraine.fr/hal-02125947}, author = {J.F. VIVO-VILCHES and A. CELZARD and V. FIERRO and I. ZIEGLER-DEVIN and N. BROSSE and A. DUFOUR and M. ETIENNE} } @article {1685, title = { Fast Pyrolysis of Heartwood, Sapwood, and Bark: A Complementary Application of Online Photoionization Mass Spectrometry and Conventional Pyrolysis Gas Chromatography/Mass Spectrometry }, journal = { ENERGY \& FUELS }, volume = {31}, year = {2017}, pages = {4078-4089}, abstract = {

Wood offers important potential for biofuel or chemical production by fast pyrolysis but exhibits variable chemical composition that impacts pyrolysis product composition. Here, fast pyrolysis of heartwood, sapwood, and bark isolated from Douglas fir (softwood) and oak (hardwood) was studied by a microfluidized bed reactor (MFBR) combined with single photoionization mass spectrometry (SPI-MS) to provide insights into the wood zone effects on the composition of pyrolysis volatiles. The difference in pyrolysis volatile composition has been clearly unraveled by principle component analysis (PCA) based on the major ions detected by SPI-MS. Some specific product markers have been defined for each wood zone (heartwood, sapwood, and bark) and related to the chemical composition of wood samples (lignin, carbohydrates, and minerals). The catalytic effect of minerals (notably potassium) has a higher impact on carbohydrate decomposition than on lignin decomposition for a given wood type. Therefore, sapwood and heartwood (for both oak and Douglas fir) can be clearly discriminated by specific markers mainly from carbohydrate pyrolysis. Interestingly, our results show that the wood cylinders exhibit a more marked wood zone effect on product compositions compared to fine powders. SPI-MS results were further compared to those of, pyrolysis gas chromatography/mass spectrometry (Py-GC/MS), and many of them are consistent. MFBR combined with SPI-MS is a selective analytical technique to figure out the effect of wood composition on pyrolysis volatiles.

}, url = {https://hal.univ-lorraine.fr/hal-01923645}, author = {L.Y. JIA and F. BUENDIA-KANDIA and S. DUMARCAY and H. POIROT and G. MAUVIEL and P. GERARDIN and A. DUFOUR} } @article {1673, title = { A Multitechnique Characterization of Lignin Softening and Pyrolysis }, journal = { ACS SUSTAINABLE CHEMISTRY \& ENGINEERING }, volume = {5}, year = {2017}, pages = {6940-6949}, abstract = {

The understanding of lignin softening and pyrolysis is important for developing lignocellulosic biorefinery in order to produce carbon fibers, polymers additives, green aromatics, or biofuels. Protobind lignin (produced by soda pulping of a wheat straw) was characterized by thermogravimetry, calorimetry (for glass transition temperature and heat of pyrolysis reactions), in situ H-1 NMR (for the analysis of the mobility of protons upon lignin thermal conversion), and solution-state C-13 and P-31 NMR (determination of functional groups in lignin). In situ rheology reveals the real-time viscoelastic behavior of lignin as a function of temperature. Upon heating, lignin undergoes softening, through glass transition overlapped with depolymerization, and is followed by the solidification of the softened material by cross-linking reactions. The lignin residues were quenched within the rheometer at the midpoint temperatures of softening and solidification regions and were further analyzed by elemental analysis, GPC-UV of acetylated THE soluble fractions, FTIR, solid C-13 NMR, and laser desorption ionization (LDI) combined with very high-resolution mass spectrometry (HRMS). We present the first report on lignin biochars analysis by LDI-HRMS. NMR and FTIR analyses provide the evolution of functional moieties in lignin residues. C-13 NMR, GPC-UV, and LDI FTICRMS analyses depict the depolymerization mechanism combined with cross-linking and demethoxylation reactions. An overall physical and chemical mechanism for the thermal conversion of alkali lignin is proposed based on these complementary analyses.

}, url = {https://hal.univ-lorraine.fr/hal-01575541}, author = {B. SHRESTHA and Y. LE-BRECH and T. GHISLAIN and S. LECLERC and V. CARRE and F. AUBRIET and S. HOPPE and P. MARCHAL and S. PONTVIANNE and N. BROSSE and A. DUFOUR} } @article {1600, title = { Characterization of biomass char formation investigated by advanced solid state NMR }, journal = { CARBON }, volume = {108}, year = {2016}, pages = {165-177}, abstract = {

Char is produced during pyrolysis of biomass and it could be valorised as soil amendment, activated carbon or to produce syngas or heat by further oxidation. The mechanisms of biochars formation have to be better understood in order to tailor their properties. For this purpose, the pyrolysis of biomass was conducted in a fixed bed reactor allowing a good control of pyrolysis conditions. Miscanthus and the macromolecules extracted from this same biomass (holocellulose, cellulose, ethanol organosolv lignin) were pyrolysed to various final temperatures (200-500 degrees C). The chemical moieties formed in the chars were studied by solid state C-13 NMR. A Cross Polarization method at the Magic Angle Spinning with Adiabatic Passage though Hartmann-Hahn conditions (CP/MAS APHH) has been found to give similar spectra than the Direct Polarization quantitative method in much shorter acquisition times. A quantitative study on the formation of aromatic structures in the network of the macromolecules in miscanthus and in the fractionated macromolecules was conducted. It is shown that below 300 degrees C xylan is the main source of aromatic formation while above this temperature the aromatization of cellulose occurs. The interactions between lignin and carbohydrates inside the network of biomass for aromatic structures formation are discussed.

}, url = {https://hal.univ-lorraine.fr/hal-01599591}, author = {Y. LE-BRECH and J. RAYA and L. DELMOTTE and N. BROSSE and R. GADIOU and A. DUFOUR} } @article {1639, title = { Effect of Potassium on the Mechanisms of Biomass Pyrolysis Studied using Complementary Analytical Techniques }, journal = { CHEMSUSCHEM }, volume = {9}, year = {2016}, pages = {863-872}, abstract = {

Complementary analytical methods have been used to study the effect of potassium on the pyrolysis mechanisms of cellulose and lignocellulosic biomasses. Thermogravimetry, calorimetry, high-temperature H-1 NMR spectroscopy (in situ and real-time analysis of the fluid phase formed during pyrolysis), and water extraction of quenched char followed by size-exclusion chromatography coupled with mass spectrometry have been combined. Potassium impregnated in cellulose suppresses the formation of anhydrosugars, reduces the formation of mobile protons, and gives rise to a mainly exothermic signal. The evolution of mobile protons formed from K-impregnated cellulose has a very similar pattern to the evolution of the mass loss rate. This methodology has been also applied to analyze miscanthus, demineralized miscanthus, miscanthus re-impregnated with potassium after demineralization, raw oak, and Douglas fir. Hydrogen mobility and transfer are of high importance in the mechanisms of biomass pyrolysis.

}, url = {https://hal.univ-lorraine.fr/hal-01416493}, author = {Y. LE-BRECH and T. GHISLAIN and S. LECLERC and M. BOUROUKBA and L. DELMOTTE and N. BROSSE and C. SNAPE and P. CHAIMBAULT and A. DUFOUR} } @article {1652, title = { Mechanisms of biomass pyrolysis studied reactor with advanced gas analysis by combining a fixed bed }, journal = { JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS }, volume = {117}, year = {2016}, pages = {334-346}, abstract = {

Slow pyrolysis of different biomasses (miscanthus, douglas fir and oak) was conducted in a U-shape fixed bed reactor combined to (1) on-line analysis of the vapors (primary tar) by soft photoionisation mass spectrometry (single photoionisation time-of-flight mass spectrometer, SPI-TOFMS), (2) quantitative off-line analysis of condensed vapors by GC*GC/MS-FID and (3) permanent gas analysis. The U-shape fixed bed reactor allows controlling external mass transfers, temperature of the bed, quenching char at targeted temperatures and quantifying mass balances. The mass yields in solid, condensable products and gas are studied between 200 degrees C and 500 degrees C. The soft on-line photoionisation analysis leads to a more interpretable mass spectra with few fragment ions and gives the evolution of the main markers of volatiles produced in real-time as a function of the temperature. The chemical structure of the markers analyzed on-line by SPI-TOFMS is assigned by GC*GC/FID-MS analysis. The mechanisms of hemicelluloses, cellulose and lignin pyrolysis in the complex network of biomass (including minerals catalytic effect) are discussed.

}, url = {https://hal.univ-lorraine.fr/hal-01923764}, author = {Y. LE-BRECH and L.Y. JIA and S. CISSE and G. MAUVIEL and N. BROSSE and A. DUFOUR} } @article {1578, title = { Catalytic conversion of methane over a biomass char for hydrogen production: deactivation and regeneration by steam gasification }, journal = { APPLIED CATALYSIS A-GENERAL }, volume = {490}, year = {2015}, pages = {170-180}, abstract = {

CH4 decomposition over a wood char was investigated as an alternative green catalyst.to produce hydrogen from hydrocarbons. Pyrolytic carbon (pyrocarbon) deposition leads to apparent deactivation of the catalyst by pore-mouth plugging. The activity of the carbon bed and its available surface area are easily restored by H2O gasification. The used char with pyrocarbon deposition was even found to be more reactive to gasification than the fresh char used in our conditions. This finding was highlighted by: (i) determination of gasification reaction extents by steam, (ii) temperature-programmed oxidation (TPO) of the fresh, used and reactivated chars and (iii) TPO under differential scanning calorimetry of these chars and demineralised chars. High-resolution transmission electron microscope (HRTEM) analysis of the chars showed different multiscale organisation of the carbon materials (disordered and graphitic mesoporous nanostructures). The fast regeneration of the used char could be attributed to the catalytic effect of the minerals present in the char that are reduced under our conditions of CH4 conversion. The predominant oxidation of the pyrocarbon compared to the char during its regeneration is evidenced through differential annealing (at 1800 degrees C) followed by XRD analysis. The oxidation of pyrocarbon is faster than the oxidation of the weakly reactive mesoporous carbon in char as shown by the HRTEM analysis. Consequently, wood char is an effective, easy to regenerate and cheap catalyst for converting hydrocarbons (CH4 or tar) into syngas.

}, url = {https://hal.archives-ouvertes.fr/hal-01227900}, author = {A. DUFOUR and A. CELZARD and V. FIERRO and F. BROUST and C. COURSON and A. ZOULALIAN and J.N. ROUZAUD} } @article {1568, title = { Characterization of Miscanthus pyrolysis by DRIFTs, UV Raman spectroscopy and mass spectrometry }, journal = { JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS }, volume = {113}, year = {2015}, pages = {402-411}, abstract = {

The aim of this work was to identify and quantify the chemical and structural modifications occurring during the pyrolysis of Miscanthus x giganteus. Miscanthus was pyrolyzed at slow heating rate (5 K/min) in the temperature range 200-400 degrees C. The biochars were then characterized by combining diffuse reflectance infrared Fourier transform spectrometry (DRIFTs) and Ultraviolet Raman spectrometry (UV Raman). In addition, the quantification of the functional groups remained on the biochars was conducted by temperature programmed desorption-mass spectrometer (TPD-MS) analysis.

DRIFT analysis showed that the decrease in the hydroxyl and C-H stretching bands and the evolution of the carboxyl vibration peak mainly occur between 300 and 350 degrees C. The evolution of the main markers (H2O, CO, CO2, CH4, and H-2) of the functional groups presents in the biochars as analyzed by TPD-MS is consistent with the spectroscopic analysis. It shows two peaks. The first one in the temperature range of 200-380 degrees C was explained by the loss of the main O- and H- containing groups and to the main primary volatile compounds. The second step (above 380 degrees C) can be interpreted by the rearrangement of the aromatic rings in the polycyclic structure.

}, url = {https://hal.archives-ouvertes.fr/hal-01230722}, author = {Y. ELMAY and Y. LE-BRECH and L. DELMOTTE and A. DUFOUR and N. BROSSE and R. GADIOU} } @article {1579, title = { High Resolution Solid State 2D NMR Analysis of Biomass and Biochar }, journal = { ANALYTICAL CHEMISTRY }, volume = {87}, year = {2015}, pages = {843-847}, abstract = {

Solid state NMR methods are required to analyze biomass as a function of its chemical or biological treatment for biofuels, chemicals, or biochar production. The native polymers network in lignocellulosic biomass and other solid materials, such as coal, coke, or biochar, can hardly be analyzed by liquid state NMR due to their poor swelling ability without chemical modification. A H-1-C-13 two-dimensional heteronuclear correlation (HETCOR) experiment with frequency-switched Lee-Goldburg (FSLG) irradiation is performed on a high field spectrometer (750 MHz). This method leads to previously unattained resolution for biomass and biochar and offers a unique ability to reveal their chemical composition. The formation of aromatic moieties from carbohydrates and lignin thermal conversion is clearly distinguished. This method can be applied to all other carbonaceous materials.

}, url = {https://hal.archives-ouvertes.fr/hal-01101584}, author = {Y. LE-BRECH and L. DELMOTTE and J. RAYA and N. BROSSE and R. GADIOU and A. DUFOUR} } @article {1543, title = {Kinetic modelling of char gasification by accounting for the evolution of the reactive surface area}, journal = {CHEMICAL ENGINEERING SCIENCE}, volume = {138}, year = {2015}, pages = {281-290}, abstract = {

In combustion and gasification reactors, solid fuels such as coal or biomass undergo a pyrolysis step to form volatiles and a char. Pyrolysis is combined with an oxidation by O-2, H2O and/or CO2 of the resultant char. Here we propose an original approach to model the oxidation of a single char particle. The intrinsic chemical reactivity of the char surface is assessed by the reactive surface area (RSA). The evolution of the RSA upon the conversion of the particle (burn-off) is modelled by a specific kinetic law similar to the law used to model the evolution of active sites in catalysis. This approach is applied on experimental results taken from the literature for coal and wood chars for O-2, H2O or CO2 gasification. The evolution of the total surface area (TSA) is modelled by the random pore model. Diffusional limitations are also accounted for.

}, url = {https://hal.archives-ouvertes.fr/hal-01196324}, author = {A. ZOULALIAN and R. BOUNACEUR and A. DUFOUR} } @article {1251, title = {Resolution solid state 2D NMR analysis of biomass and biochar }, journal = {Analytical Chemistry }, volume = {87}, year = {2015}, month = {2015}, chapter = {843}, author = {Y. LEBRECH and L. DELMOTTE and J. RAYA and N. BROSSE and R. GADIOU and A. DUFOUR} } @article {617, title = {Detailed process modeling of a wood gasification combined heat and power plant}, journal = { Biomass \& Bioenergy}, volume = {51}, year = {2013}, month = {2013}, chapter = {68-82}, author = {J. FRANCOIS and L. ABDELOUAHED and G. MAUVIEL and F. PATISSON and O. MIRGAUX and C. ROGAUME and Y. ROGAUME and M. FEIDT and A. DUFOUR} } @article {618, title = {Modeling of a Biomass Gasification CHP Plant: Influence of Various Parameters on Energetic and Exergetic Efficiencies}, journal = {Energy \& Fuels}, volume = {27}, year = {2013}, month = {2013}, chapter = {7398-7412}, author = {J. FRANCOIS and G. MAUVIEL and M. FEIDT and C. ROGAUME and Y. ROGAUME and O. MIRGAUX and F. PATISSON and A. DUFOUR} } @article {594, title = {Revealing the chemistry of biomass thermal conversion by means of tunable synchrotron ionisation - mass spectrometry}, journal = {RCS Advances}, volume = {3}, year = {2013}, month = {2013}, chapter = {4786-4792}, author = {A. DUFOUR and J. WENG and L. JIA and X. TANG and R. FOURNET and N. BROSSE and B. SIRJEAN and G. MAUVIEL and F. QI} } @article {1240, title = {Miscanthus: a fast growing crop for bio-fuels and chemicals production }, journal = {Biofuels Bioproducts and Biorefining}, volume = {6}, year = {2012}, month = {2012}, chapter = {580}, author = {N. BROSSE and A. DUFOUR and M. XIANZHI and Q. SUN and A. RAGAUSKAS} } @article {1238, title = {Origin of molecular mobility during biomass pyrolysis as revealed by in situ 1H 1NMR analysis}, journal = {ChemSusChem}, volume = {5}, year = {2012}, month = {2012}, chapter = {1}, author = {A. DUFOUR and M. CASTRO-DIAZ and N. BROSSE and M. BOUROUKB and C. SNAPE} }