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This book highlights the processes of biomass thermochemical conversion, covering topics from combustion and gasification, to pyrolysis and liquefaction. Heat, power, biofuels and green chemicals can all be produced by these thermochemical processes. The different scales of investigation are presented: from the bioenergy chains, to the reactors and molecular mechanisms. The author uses current research and data to present bioenergy chains from forest to final use, including the biomass supply chains, as well as the life cycle assessment of different process chains. Biomass conversion reactors are also presented, detailing their technologies for combustion, gasification and syngas up-grading systems, pyrolysis and bio-oil upgrading. The physical-chemical mechanisms occurring in all these reactors are presented highlighting the main pathways for gas, char and bio-oil formation from biomass. This book offers an overview of biomass valorization for students, engineers or developers in chemistry, chemical, environmental or mechanical engineering.

Clostridium acetobutylicum, a promising organism for biomass transformation, has the capacity to utilize a wide variety of carbon sources. During pre-treatments of (ligno) cellulose through thermic and/or enzymatic processes, complex mixtures of oligo saccharides with beta 1,4-glycosidic bonds can be produced. In this paper, the capability of C. acetobutylicum to ferment glucose and cellobiose, alone and in mixtures was studied. Kinetic studies indicated that a diauxic growth occurs when both glucose and cellobiose are present in the medium. In mixtures, d-glucose is the preferred substrate even if cells were pre grown with cellobiose as the substrate. After the complete consumption of glucose, the growth kinetics exhibits an adaptation time, of few hours, before to be able to use cellobiose. Because of this diauxic phenomenon, the nature of the carbon source deriving from a cellulose hydrolysis pre-treatment could strongly influence the kinetic performances of a fermentation process with C. acetobutylicum.

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.

Carbon monoliths were tested as electrodes for vanadium redox batteries. The materials were synthesised by a hard-templating route, employing sucrose as carbon precursor and sodium chloride crystals as the hard template. For the preparation process, both sucrose and sodium chloride were ball-milled together and molten into a paste which was hot-pressed to achieve polycondensation of sucrose into a hard monolith. The resultant material was pyrolysed in nitrogen at 750 °C, and then washed to remove the salt by dissolving it in water. Once the porosity was opened, a second pyrolysis step at 900 °C was performed for the complete conversion of the materials into carbon. The products were next characterised in terms of textural properties and composition. Changes in porosity, obtained by varying the proportions of sucrose to sodium chloride in the initial mixture, were correlated with the electrochemical performances of the samples, and a good agreement between capacitive response and microporosity was indeed observed highlighted by an increase in the cyclic voltammetry curve area when the SBET increased. In contrast, the reversibility of vanadium redox reactions measured as a function of the difference between reduction and oxidation potentials was correlated with the accessibility of the active vanadium species to the carbon surface, i.e., was correlated with the macroporosity. The latter was a critical parameter for understanding the differences of energy and voltage efficiencies among the materials, those with larger macropore volumes having the higher efficiencies.

Ammonia is well suited to favor deprotonation process in electrospray ionization mass spectrometry (ESI-MS) to increase the formation of [M – H] – . Nevertheless, NH 3 may react with carbonyl compounds (aldehyde, ketone) and bias the composition description of the investigated sample. This is of significant importance in the study of complex mixture such as oil or bio-oil. To assess the ability of primary amines to form imines with carbonyl compounds during the ESI-MS process, two aldehydes (vanillin and cinnamaldehyde) and two ketones (butyrophenone and trihydroxyacetophenone) have been infused in an ESI source with ammonia and two different amines (aniline and 3-chloronaniline). The (+) ESI-MS analyses have demonstrated the formation of imine whatever the considered carbonyl compound and the used primary amine, the structure of which was extensively studied by tandem mass spectrometry. Thus, it has been established that the addition of ammonia, in the solution infused in an ESI source, may alter the composition description of a complex mixture and leads to misinterpretations due to the formation of imines. Nevertheless, this experimental bias can be used to identify the carbonyl compounds in a pyrolysis bio-oil. As we demonstrated, infusion of the bio-oil with 3-chloroaniline in ESI source leads to specifically derivatized carbonyl compounds. Thanks to their chlorine isotopic pattern and the high mass measurement accuracy, (+) ESI Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) unambiguously highlighted them from the numerous C x H y O z bio-oil components. These results offer a new perspective into the detailed molecular structure of complex mixtures such as bio-oils. Graphical Abstract ᅟ

The pyrolysis of the lignocellulosic biomass is a promising process to produce biofuels or green chemicals. Specific analytical methods have to be developed in order to better understand the composition of biomass and of its pyrolysis products and therefore to optimize the design of pyrolysis processes. For this purpose, different biomasses (Douglas and Miscanthus) and one biochar were analyzed by laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (LDI FT-ICR MS). This method allowed the biomass and biochar to be analyzed without any sample preparation and with a spatial resolution of about 100 μm. The influence of LDI conditions (laser wavelength and laser irradiance) and the nature of the biomass and biochar on the obtained mass spectrum were investigated. The nature and origin of the observed ions highly depended on LDI conditions. In the softest laser–biomass interaction conditions (low laser irradiance), the detected ions were related to the nature of the investigated biomass. Indeed, the main part of the detected species came from the different biomass subunits and was produced by photolysis of covalent bonds. When more severe laser irradiation conditions were used, the obtained mass spectra gathered the ions relative to (i) the chemical components of the investigated samples, (ii) the recombination products of these species in the gas phase after their ejection from the sample surface, and (iii) the compounds produced by laser pyrolysis of the sample. This was expected to be useful to mimic thermal pyrolysis. Graphical Abstract

The influence of the gasification temperature and Equivalence Ratio (ER) on the behavior of an industrial low-grade Solid Recovered Fuel (SRF) was investigated in an air bubbling fluidized bed. The studied SRF exhibits an intermediate composition between biomass-rich SRF and plastic-rich SRF. Its Lower Heating Value (14 MJ/kg) is low since its ash content is very high (35 wt%). But surprisingly, the Cold Gas Efficiency and the Carbon Conversion were relatively high with this type of low-grade SRF. As a result, the syngas produced is quite rich (LHV > 8 MJ/m 3 STP) and it may be valorized in gas engines. H 2 S, HCl, HCN and NH 3 in the syngas were analyzed. These results confirm that inorganic gases are an important issue for the valorization of SRF as fuel in gasification processes, even if significant parts of S, N and Cl are not converted into inorganic gases. Graphic Abstract

Ni supported over activated carbon (AC) based on olive stones were tested for methane decomposition to produce hydrogen. Physical (by H2O ) and chemical (by H3PO4 ) activations were compared. Kinetic parameters of methane decomposition were determined depending on Ni load, methane partial pressure and reaction temperature. The catalysts were characterized before and after reaction by N2 adsorption, X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The catalysts showed good initial activities that increased with temperature and nickel load, reactivity decreased with time. The reaction orders were 0.63 and 0.74 and the activation energies were 122 and 139 kJ/mol for physically and chemically activated carbon, respectively. BET surface areas and pore volumes decreased dramatically after reaction due to the deposit of carbon on the support. Ni stayed under its metallic form on the physically AC whereas it was mainly present as Ni12P5 over the chemically activated one. TEM characterization revealed the formation of well-organized carbon nano-onions surrounding Ni particles on the physically activated carbon. Nano-onions were not formed around Ni12P5 particles in the chemically activated carbon. The physical activation allowed the synthesis of catalysts with a better stability for methane conversion than what chemical activation would allow.

60 years after its downfall, Japanese imperialism remains a hot issue, straining the relationship between Japan and its neighbors, specifically China and South Korea. Today, it is perceived by some to be on the rise again. Some history books downplay the Japanese atrocities during WWII. A former Prime Minister infuriated the whole region with his visits to the Yasukani Shrine where war criminals are buried. And the recent upgrade of the Defense Agency to a full ministry is seen as another strong signal. So is Japan on a dangerous path again? For the first time, a compelling investigation has been led in Japan as well as China and Korea. Its findings are quite troubling.