Search

International audience; This work aims to understand the mechanisms occurring during the microstructural transformation of clay-based mixtures. For that, the combination of various standard and advanced characterization techniques was used. This original approach allowed an outstanding description of complex mechanisms involved during the firing, bringing new insights in regards to the state-of-the-art. Thus, the formation of viscous glassy phases and the associated effects in terms of densification acceleration were particularly revealed by following the damping of Acoustic Resonance (AR) signals and by dynamic high-temperature Scanning Electron Microscopy (SEM). Further STEM-EDX (Scanning Transmission Electron Microscopy Coupled with Energy Dispersive X-ray) analyses revealed that the glassy phase resulting from the solidification of the viscous phase is predominantly composed of silicon, aluminum, oxygen, and potassium. This study also evidenced that the behavior of a binary clay-based mixture was not always described by a mixing law model.

International audience; Syngas produced from biomass and biowaste gasification is a versatile renewable fuel and feedstock for chemical synthesis or heat and power production. Bio-syngas can be produced from different biomass feedstock (e.g. lignocellulosic biomass, pyrolysis oil, bioethanol, biogas) through thermal and/or catalytic reforming and gasification processes. The typical components of raw syngas can be classified into three groups: non-condensable gases (e.g. H2, CO, CH4 and CO2), condensable gases (e.g. H2O and tars) and impurities (e.g. HCl, NH3, H2S and particulates). Depending on the application, raw syngas may need to be cleaned of impurities and conditioned to adjust the H2/CO ratio in order to meet the requirements of environmental regulations and downstream processes respectively. Hence, an accurate characterization of the syngas chemical composition, at the different processing stages, is important to control and optimize the process efficiency. In this chapter, various methods and equipment for sampling, preconditioning and analyzing the three groups of syngas components will be discussed. Analyses of the equipment detection limits, gas matrix sensitivity, and overall accuracy will also be made.

International audience; Three main components of biomass were pyrolyzed individually in a closed reaction system at 500–700 °C for 60s and 90s. Then bio-oil heavy compounds were further analyzed with Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) and Kendrick mass defect (KMD) analysis. The evolution paths of heavy compounds for the different pyrolysis stages were proposed. It was found that the sugars and phenolic-like species in heavy compounds were the most active substances during secondary reactions. Moreover, the rising temperature promoted this secondary reaction of phenolic-like species as the decrease in their abundances growing from 13% to 54%, while contrarily inhibited it for hemicellulose as the decrease in their abundances changing from 44% to −2%. The lignin-derived lipids and unsaturated hydrocarbons that generated in the secondary reactions increased with rising temperature. KMD analysis showed that the heavy compounds of cellulose and hemicellulose prefer homologous evolution during pyrolysis, while those of lignin had more complex evolution paths like cracking and recombination.

International audience; Structural properties of carbonized cellulose were explored to conjugate the outcomes from various characterization techniques, namely X-ray diffraction (XRD), Raman spectroscopy, and high-resolution transmission electron microscopy. All these techniques have evidenced the formation of graphene stacks with a size distribution. Cellulose carbonized at 1000 and 1800 °C at a heating rate of 2 °C/min showed meaningful differences in Raman spectroscopy, whereas in XRD, the differences were not well pronounced, which implies that the crystallite sizes calculated by each technique have different significations. In the XRD patterns, the origin of a specific feature at a low scattering angle commonly reported in the literature but poorly explained so far, was identified. The different approaches used in this study were congruous in explaining the observations that were made on the cellulose-derived carbon samples. The remnants of the basic structural unit (BSU) are developed during primary carbonization. Small graphene-based crystallites inherited from the BSUs, which formerly developed during primary carbonization, were found to coexist with larger ones. Even if the three techniques give information on the average size of graphenic domains, they do not see the same characteristics of the domains; hence, they are not identical, nor contradictory but complementary. The arguments developed in the work to explain which characteristics are deduced from the signal obtained by each of the three characterization techniques relate to physics phenomena; hence, they are quite general and, therefore, are valid for all kind of graphenic materials.

International audience

International audience; Municipal solid waste (MSW) incinerators require effective flue gas treatment (FGT) to meet stringent environmental regulations. However, this in turn generates additional environmental costs through the impacts of materials and energy used in the treatment – these impacts are currently scarcely known. Therefore, this study uses life cycle assessment to estimate the impacts of different FGT systems typically found in modern MSW incinerators. A total of 12 scenarios are modelled to consider different combinations of the following eight technologies: electrostatic precipitators and fabric filters for removal of particulate matter; dry, semi-dry and wet scrubbers for acid gases; selective non-catalytic and catalytic reduction of nitrogen oxides (NOx); and activated carbon for removal of dioxins and heavy metals. The data are sourced from 90 full-scale incinerators operating in France. The results reveal that a dry system using sodium bicarbonate and selective non-catalytic reduction (SNCR) is the best option for seven out of 18 impacts, including climate change (37.1 kg CO2 eq./t MSW). By contrast, a dry system with calcium hydroxide and selective catalytic reduction (SCR) has the highest impacts in six categories, including climate change (102 kg CO2 eq./t MSW). The wet systems have higher impacts than the dry alternatives, with the semi-dry options being in between. Compared to SNCR, the use of SCR decreases the NOx-related impacts (fine particulate matter formation, terrestrial acidification and photochemical ozone formation) but increases other impacts. For example, the SCR systems have 49–284% greater climate change and 43–150% higher depletion of fossil resources than their SNCR counterparts. Overall, all FGT systems reduce significantly fine particulate matter formation (by 81–88%), photochemical ozone formation (76–90%) and terrestrial acidification (83–90%). However, they also cause 14 other impacts which would not be generated if the flue gas was left untreated, thus creating additional environmental costs. These include climate change, resource depletion and human and ecotoxicities. Therefore, these trade-offs should be considered carefully to minimise the unintended environmental consequences of flue gas treatment from incineration of MSW.

Kitchen waste (KW) has gradually become a prominent problem in municipal solid waste treatment. Hydrothermal liquefaction (HTL) is a promising method used to make fuel oil from food and KW. However, the upgrading of bio-oil is particularly important for the sake of industrial reuse. In this study, the KW from university restaurants was subjected to HTL experiments in order to study theoretical feasibility. With the change of conversion temperature and residence time, the optimal conversion working conditions in this study were determined according to the quality and yield of the bio-oil. Moreover, the bio-oil upgrading effects of different additives (hydrogen chloride, sodium hydroxide, and iron(III) chloride) on the HTL of KW were studied. Alkaline additives have an inhibitory effect on the bio-oil yield and positive effect on coke yield. Acidic additives and iron (Fe)-containing additives can promote bio-oil yield. As an important aspect of upgrading, the effect on the nitrogen content of bio-oil with additives was revealed. The alkaline and Fe-containing additives have little effect on reducing the viscosity of the bio-oil while with the appropriate ratio (2.5 mol•kg−1) of acidic additives to the raw material, the static and dynamic fluidity of the oil phase products are reduced to about 0.1 Pa•s.

International audience; Nanocellulose has been established to be one of the most promising green resources of modern times due to its inherent properties and renewability. In this chapter, we present the fundamentals of nanocellulose-based composite materials and their significance in electronics applications. The composites involving various types, including films, papers, and aerogels comprising nanocellulose incorporated with conducting polymers, carbon nanomaterials, metal nanoparticles and oxides, etc. have been discussed. The underlying mechanism for nanocellulose composites to be utilized for electronics device fabrication includes flexible and printed electronics, energy storage and conversion devices, and dielectric and microwave absorbing systems has been systematically presented. The ability of nanocellulose to provide mechanical supports for freestanding flexible and thermally stable electronic devices has been widely exploited. This chapter aims at providing an outline in the fabrication process and significance of nanocellulose composites in the entire electronics.

International audience; Cheap alumino-silicate materials such as clay materials and Y zeolite were selected for the catalytic pyrolysis of waste engine oil in a fixed bed reactor. A cheaper route of Y zeolite synthesis involving hydrothermal activation of the raw clay and hydrothermal synthesis was employed. X-ray diffraction technique, scanning electron microscopy, Fourier transform infra-red, and nitrogen desorption method were used to characterize the intermediate phases formed during the hydrothermal treatment of the clay and the synthesized Y zeolite during the hydrothermal processes. The chemical compositions of the liquid phase of catalytic pyrolysis were characterized by gas chromatography coupled with mass spectroscopy (GC–MS). The results revealed that the alkaline concentration strongly influenced the activation of the raw clay to obtain a useful phase for the subsequent synthesis of the Y zeolite. The synthesis improved the surface area from 29 m2/g for the clay to 745 m2/g for the zeolite. The catalytic pyrolysis resulted in diesel fractions of 64.8 and 54.7%, respectively for the Y zeolite and the clay. It was observed that the gasoline fractions increased to 20.5 and 19.1%, respectively for the zeolite and the clay. In the diesel fraction, the zeolite selectively improved the yield of the cyclo-alkanes which are key constituents in terms of the quality of diesel. Y zeolite was successfully derived from a natural clay and tested in the pyrolysis of waste engine oil. The synthesis route provides the opportunity to improve the catalytic property of the natural clay.

International audience; This review analyzes the literature from the 80’s to the beginning of 2020 and covers the use of carbon materials as supports for cobalt-based catalysts used in the Fischer Tropsch reaction. The article is composed of two sections. The first one details the reactivity of carbon supported cobalt catalysts with a particular focus on: i) reaction mechanisms and conditions, ii) effect of cobalt particle size, iii) confinement effects, iv) hydrogen spillover, and v) deactivation mechanisms. In the second part, the different methods of Co/C catalyst preparation are presented, and the influence of several parameters such as the type of supports and its functionalization, the metal loading or the catalyst activation on the catalytic performances is discussed. This work also provides some perspectives in the field.

International audience; It is well established that the transport sector contributes significantly to the global warming because of the high Carbon dioxide emission rate. A significant effort is being made in aeronautics for instance to green this sector. Green and decarbonized hydrogen processes taken at different Technology Readiness Levels (TRL) are considered in this article It mainly concerns co-electrolysis of water with CO2, pyrolysis and gasification of biomass and biowaste, reforming of biogas and biological conversion of both biomass and biowaste.; Le secteur du transport a un impact important sur les émissions de gaz carbonique, contribuant de manière significative au changement climatique. Dans ce contexte, le secteur aéronautique entreprend des efforts importants pour améliorer son empreinte carbone par l’utilisation de carburants verts ou décarbonés. L’hydrogène apparaît comme une solution d’avenir en tant que carburant pour les systèmes aéronautiques (avions et dispositifs au sol). Cet article aborde les procédés de production d’hydrogène renouvelable et vert à partir de carbone issu de la photosynthèse. Les procédés comme la co-électrolyse de l’eau, la pyrolyse et la gazéification de la biomasse et des biodéchets, le reformage du biogaz et la conversion biologique de la biomasse et des biodéchets.

International audience; The main objective of this work was to analyze the physico-chemicals properties of biochars produced from the steam gasification of different lignocellulosic agrowastes, and determine the suitability of these materials to be used in soil amendment and remediation applications. Steam gasification biochars from three lignocellulosic agrowastes were extensively characterized. Coconut shells (CS), bamboo guadua (BG), and oil palm shells (OPS) were chosen as raw materials, considering their different macromolecular structure and inorganic composition. The biochars composition, morphology, pH, acid neutralization (ANC) and cation exchange (CEC) capacities, as well as their mineral release at different conditions were evaluated and compared. The experimental results showed that the inorganic content and composition of the biochars have a stronger impact on their properties for soil applications, in comparison to their organic composition and morphology. In particular, BG biochar, the sample with the highest mineral content, exhibited the most notable cation exchange (45 cmolc/kg) and acid neutralization capacities (125 cmol H+/kg), together with the greatest release of plant micro and macro-nutrients. In the case of biochars with low mineral content, higher CEC and ANC were most related to the presence of oxygen-containing functional groups in their surface. Considering that agricultural residues come from numerous sources and activities, the presented results usefully contribute to the comprehension of the relationship between the raw biomass characteristics, the physico-chemical properties of steam gasification biochars, and their expected performance in soil applications, opening a new promising valorization pathway for these materials.

International audience; Up-to-date, solar salt (a mixture of 60 mass% NaNO3 and 40 mass% KNO3) is practically the only media for thermal energy storage (TES) in concentrated solar power (CSP). This commercial product’s utilization is limited below 550 °C to avoid an irreversible thermal decomposition. The development of new performing TES materials is decisive for the deployment of CSP technology. Our recent work reported promising results obtained with mono-alkali polyphosphate (M-PO3) as TES materials. These materials can work up to around 900 °C, but their melting point is still high, which is at least 628 °C. In order to lower their melting point, binary and ternary mixtures of alkali polyphosphates are investigated in this work. Dif- ferent mixtures made of two or three alkali polyphosphates were prepared and studied using thermal analysis methods. The most promising mixture found in this work was the ternary Li-Na-K-PO3, which contained 33.3% (mol%) of each alkali metal. This mixture can be used as a liquid TES material in the temperature range of 398 to 900 °C. The results open new prospects for the development of the thermal energy storage field.

International audience; Chitin and chitosan are the second most abundant natural biopolymers in the curst of the earth. These polysaccharide biopolymers have a long linear chain-like structure connected with β-d glucosidic linkage with the functionalizable surface groups. Because of the structural features, these biomaterials exhibit unique physical, chemical, mechanical and optical properties, which contributed to the tunable and outstanding properties such as low density, high porosity, renewability, natural biodegradability, and environmental friendliness, etc. Chitin was synthesized via mechanical, chemical, chemo-mechanical, and eco-friendly biological methods and the deacetylation of the synthesized chitin carried for the preparation of chitosan. With the chemical modification used for the preparation of chitosan, there occurs some minor change in characteristics; however, most of the properties were relatable due to major similarities in the microstructures. The inherent antibacterial, non-toxic, and biodegradable properties with the ease of processibility of both polymer has the potential to become a successful alternative to its synthetic counterparts for energy and environmental applications. However, the poor mechanical and thermal properties in comparison to the conventional alternatives have restricted its widespread applications. This review addresses various areas such as extraction techniques of chitin and synthesis of chitosan, discussion of the common characteristics of both polymers together such as crystallinity, thermal properties, mechanical properties, hydrophilicity, and surface charge. Moreover, this review paper also addresses the common functionalization techniques for both polymer and the use of both unmodified chitin and chitosan along with their derivatives in environmental and energy applications such as air pollution, heavy metal adsorption, dye adsorption, biosensors, EMI shielding, fuel cell, solar cell, lithium-ion batteries, and biofuels.

International audience; This study focusses on reporting a facile one-step synthesis method to fabricate calcium phosphate-microcrystalline cellulose composite with an enhanced surface area. The composite preparation is done using a simple one-step method called co-precipitation method under ambient and 60 °C temperature. The calcium carbonate and orthophosphoric acid are taken, which are the two best known widely available starting materials for the synthesis of calcium phosphate. The sample is collected and taken for the drying process in an oven at 105 °C. The characterizations like XRD, SEM, BET, FTIR, TGA, and DSC of the demonstrated composites are done. From BET analysis, it can be concluded that the surface area of the demonstrated composite enhances substantially after the incorporation of the microcrystalline cellulose.

International audience; Phosphorus (P) is a non-renewable resource, and its recovery and recycling are necessary for meeting future P demands and environmental conservation. Ash and hydrochar from incineration and hydrothermal liquefaction (HTL) of municipal sludge, respectively, represent promising sources for efficient P recovery. The full-scale application of wet-chemical techniques has proven their technical feasibility for P recovery from sludge-derived ash. HTL for sludge treatment has received significant attention for producing biocrude with net-positive energy recovery. P recovery from the solid by-product of sludge HTL, hydrochar, is a critical step in holistic sustainable sludge management. This review aims to guide P recovery from sludge-derived ash and hydrochar by presenting recent advances in wet-chemical extraction and precipitation. By comparing their characteristics, ash and hydrochar derived from municipal sludge exhibit similar feasibilities and challenges for P recovery. Extraction is recognized as the critical step for P recovery. The advantages and disadvantages of various P extraction approaches are provided. Acidic extraction achieves high efficiency (up to 100%) but requires removal of co-extracted heavy metals. Alkaline extraction prevents metals contamination but shows low efficiency (

International audience; Pressed plates ceramics made of gross-milled bottom ashes and waste clay, were made using technologies available in the building bricks and tiles industry, to ease production upscaling at low-cost. These sintered ceramics are intended for use as a high-temperature thermal energy storage material. They represent an alternative to the waste-based petrurgic ceramics previously developed for this application. Post-treated incinerator bottom ashes from a commercial incinerator were collected, characterized and processed to form ceramic materials, using clay as a binder. Ashes were milled, dried, and mixed with various amounts of an illitic clay (produced as washing mud by a quartz quarry in proportions from 20 to 70% dry weight) prior to uniaxial pressing (12 × 5 × 1 cm slabs) and firing at various temperatures, ranging from 1050 to 1125 °C. The sintered samples have been characterized in terms of volumic mass, mechanical strength, thermal capacity and thermal conductivity. Their mineral structure has also been studied. The resulting sintered ceramics exhibit relatively high mechanical resistance and low thermal conductivity, along with moderate volumic mass. These properties allow envisioning the use as filler material for thermocline thermal storage systems (structured beds), and could be interesting for further work regarding applications in the construction field (bricks, tiles, pavements…).

International audience; Calcium looping (CaL), based on cyclic carbonation/calcination using lime-based sorbents, is a promising technology for post-combustion CO2 capture. An important obstacle of this technology is the decay of sorbent over multiple cycles. Steam re-activation is a potential approach to improve the sorbent reactivity, however, the effects of both in-situ high-temperature steam (in carbonator or/and calcinator) and ex-situ low-temperature steam (steam hydration in hydrator) are still a matter of debate. Here, a bubbling fluidised bed reactor was used to investigate three steam addition options: steam addition during carbonation stage, or during calcination stage, or intermediate steam hydration after each CaL cycle. A CaO sorbent was tested under varying steam concentrations up to 40 vol.% for 10 CaL cycles (carbonation: 650 °C, calcination: 900 °C). Compared to the dry condition, steam addition during carbonation and intermediate steam hydration were both found effective for CaO re-activation. For the former, the improved sorbent reactivity was mainly attributed to an increased pore volume enhancing the extent of carbonation in kinetic regime; while for the latter, the formation of cracks accelerated the rate of diffusion. Nevertheless, decreasing the hydration temperature was detrimental to sorbent reactivity due to enhanced sintering upon cooling. In case of steam addition during calcination, the sorbent was affected negatively or positively depending on the concentration of steam. At higher steam concentrations (20, 40 vol.%), the sorbent reactivity was significantly decreased due to sintering associated with larger pores and lower surface areas. Overall, steam addition during carbonation was recommended for sorbent re-activation.

International audience; • H 2 S removal from the gas phase using calcium carbonate based solid wastes. • Validation of a triphasic gas/liquid/ solid process at the pilot scale. • Validation of the process with a real gaseous effluent. Keywords: H 2 S removal Calcium carbonate Solid waste Triphasic process Slurry bubble column pilot This work is devoted to the removal of H 2 S from the gas phase using a suspension of calcium carbonate-based residues, recovered from the production of sodium bicarbonate. A 145 L (1.6 m height and 0.34 m internal diameter) slurry bubble column (SBC) reactor was used. The gaseous effluent was bed from the bottom and get out from the top of the column. The suspension (2-20 wt%) was recirculated from the bottom to the top by a pump. This created a counter-current regime between the gas phase (from the bottom to the top) and the liquid phase (from the top to the bottom) which favor the gas/liquid exchange inside the reactor. The influence of different parameters including solid concentration in the suspension (w s), recirculating rate of the suspension (Q R), inlet gas flow rate (Q G), and volume of the suspension, was investigated. The results obtained with this confirmed those at the lab scale, for both synthetic gaseous effluent (H 2 S diluted in compressed air) and real gaseous effluent emitted by the buffer tank of a wastewater treatment plant. This allows validating the technology before its deployment at the large industrial scale for H 2 S removal from the gas phase.

International audience; There is a piqued interest in development of biobased sorbents for water treatment. Here in we reported, the fabrication of mechanically strong nanopapers by mixed dimensional assembly of 1D Cellulose nanofibers and 2D amino functionalized graphene oxide for water treatment. The fabricated amino functionalized GO/ cellulose nanofiber (AMGO-CNF) nanopaper showed superior antibacterial resistance towards Escherichia coli MTCC 1610 and Klebsiella due to the enhanced surface roughness which was confirmed from SEM and AFM studies. The amino group present in the AMGO enhanced the adsorption efficiency of the nanopaper towards methyl orange dye. The fabricated nanopaper showed an adsorption of 11.05 mg/gm 30 mg/L concentration at pH 2. Maximum adsorption was observed at pH 2 which was due to protonation of amine group. Moreover, the fabricated membrane showed excellent hydrolytic stability which can be corroborated to the surface roughness and reduced hydrophilicity. The investigation into the surface chemistries of cellulose nanofibers beyond the adoption of toxic solvents can enhance the economic usefulness of the process and yield a new eco-friendly adsorbent material that is agreeable to adsorbing various toxic pollutants.

International audience; The Fischer‐Tropsch reaction transforms syngas into high added value products, among which liquid fuels. Numerous parameters determine catalytic activity and selectivity towards the most desired hydrocarbons. The performances of cobalt‐based catalysts used in the reaction are known to depend critically on Co particle size and crystallographic phase. Here, we present a comparative study of Co‐based catalysts supported on three carbon supports: multi‐wall carbon nanotubes, carbon nanofibers and a fibrous material. Our results show that, while the selectivity towards C5+ follows the expected tendency with respect to Co particle size, this is not the case for the TOF. These results can be rationalized considering that the amount of H 2 uptake on each catalyst increases with oxygen and defect concentration on the support. The catalyst, on the support presenting many edges and oxygen surface groups, necessary for H 2 spillover, presents the highest activity. Furthermore, the hydrogen spillover contributes to the enhancement of olefin hydrogenation and methane production.

International audience; The aim of this work was to study five (5) selected local raw clay materials from Ghana using different characterization techniques such as Thermogravimetric/Differential Thermal Analysis (TG/DTA), X-ray diffraction (XRD), Fourier Transform Infra-red Spectroscopy (FTIR), Scanning Electron Microscopy equipped with Energy Dispersive X-ray Spectroscopy (SEM-EDX) and Nitrogen Desorption (Brunauer-Emmett-Teller, BET) specific surface area analysis. The clay samples studied are; Nkroful kaolin (NK), Amanfrom kaolin (AK), Ball clay (BC), Akyem Feldspar (AF) and Akwatia silica (AS). SEM and EDX show the morphological features of the five clay samples and also confirm the presence of some dominant elemental compositions such as aluminium and silicon in all the samples. FTIR show that the vibrations spectra in the region around 3,600-3,700 cm-1 and 700-800 cm-1 are due to M-OH groups and that at 900-1000 cm-1 corresponds to Si-O-Si modes. BET analysis gives specific surface area of the clay samples as NK (4.6 m2/g), AK (21.9 m2/g), BC (25.50 m2/g), AS (0.79 m2/g) and AF (0.49 m2/g). X-ray diffraction pattern confirm the presence of quartz as the major reflection in all the samples analysed and only kaolinite reflections appeared in three of the samples (NK, AK and BC). All the kaolinite clays (NK, AK and BC) are suitable starting materials for the fabrication of electroporcelain insulators, catalytic converters and diesel particulate filters.

International audience; The unique geographical location of waterworks and wastewater treatment plant (WWTP) in Graulhet (France) profited the environmental resource integration and “Circular Economy.” Alum sludge from a local waterworks was introduced to co- conditioning and dewatering with waste-activated sludge from a nearby WWTP to examine the role of the alum sludge in improving the dewaterability of the mixed sludge. Experiments demonstrated that the optimal mixing ratio was 1:1 (waste- activated sludge/alum sludge, v/v). Alum sludge has been shown to beneficially enhance mixed sludge dewaterability, by decreasing both the specific resistance to filtration (SRF) and the capillary suction time (CST). Moreover, the optimal polymer (Sueprfloc-492HMW) dose for the mixed sludge (mix ratio 1:1) was 200 mg/L, highlighting a huge savings (14 times) in polymer addition without alum sludge involvement. In addition, cost-effective analysis of its potential full-scale application has demonstrated that the initial investment could be returned in 11 years. The co-conditioning and dewatering strategy can be viewed as a “win-win” strategy for the Graulhet, France, water and wastewater industry.

This book provides authoritative information, techniques and data necessary for the appropriate understanding of biomass and biowaste (understood as contaminated biomass) composition and behaviour while processed in various conditions and technologies. Numerous techniques for characterizing biomass, biowaste and by-product streams exist in literature. However, there lacks a reference book where these techniques are gathered in a single book, although such information is in increasingly high demand. This handbook provides a wealth of characterization methods, protocols, standards, databases and references relevant to various biomass, biowaste materials and by-products. It specifically addresses sampling and preconditioning methods, extraction techniques of elements and molecules, as well as biochemical, mechanical and thermal characterization methods. Furthermore, advanced and innovative methods under development are highlighted. The characterization will allow the analysis, identification and quantification of molecules and species including biomass feedstocks and related conversion products. The characterization will also provide insight into physical, mechanical and thermal properties of biomass and biowaste as well as the resulting by-products.

International audience; The clean and efficient energy production from municipal solid waste (MSW) is highly desirable due to increasing energy demand and environmental concerns. In this study, four incineration- (S1) and gasification-based (S2 with combustion boiler, S3 with gas turbine/combined cycle and S4 with internal combustion engine) MSW treatments were compared using methods of environmental life cycle assessment (LCA) and exergetic life cycle assessment (ELCA). LCA was applied to measure the environmental performances and ELCA was supplemented to reflect the thermodynamics efficiencies. Afterwards, cumulative degree of perfection (CDP) and abatement exergy (AbatCExC) efficiency of the considered systems were also calculated to determine the imperfection and environmental sustainability of the processes. Results showed that gasification-based systems were effective to mitigate the environmental impacts of acidification, nutrient enrichment, and photochemical ozone formation potential, but caused higher global warming impacts. The S3 system exhibited the best performance from both environmental and exergetic perspective, due to its high net efficiency of electricity generation and low exhaust emission into air. Results from ELCA indicated that the rest two gasification-based systems (S2 and S4) were inefficient as compared to MSW direct incineration, mainly due to auxiliary energy consumption for MSW pretreatment and more conversion steps. The CDP and AbatCExC of the systems in descending order was expressed as S3 system > S1 system > S2 system > S4 system.

International audience; Nanocellulose is a sustainable, renewable and eco-friendly nanomaterial with fascinating properties like high strength, low density, high specific surface area, high aspect ratio etc. Nanocellulose surface comprises of large number of hydroxyl groups which facilitates a wide range of surface chemistries and can be tailored for specific applications. These properties of nanocellulose suggests huge potential for various engineering applications. This unique property makes them as a promising candidate for various applications. Now a days, the innovative nanocellulose aerogels have gained substantial attention in the scientific community due to their renewability, good mechanical properties, low density, high porosity, natural biodegradability, and environmental friendliness. These attractive properties facilitate the use of nanocellulose aerogels in various environmental and engineering applications. This article reviews recent attempts to apply nanocellulose aerogels as efficient materials for water purification, air filtration, flame retardancy, oil absorption etc.

International audience; Wood waste containing halogenated compounds such as polyvinyl chloride (PVC) is in abundant supply, although the pyrolysis of such waste feedstock for energy production may cause corrosion and environmental problems due to the release of HCl gas. Hence, there is a need to understand the pyrolysis behaviour of chlorine-contaminated wood in order to develop methods that minimise the impact of chloride species on pyrolysis equipment and product quality. In literature, few studies exist on the kinetic analysis of wood and PVC co-pyrolysis. The existing models assume a single-step reaction with an n-order reaction mechanism for the entire process, which may lead to large errors in the kinetic parameters estimated. Therefore, in this paper, we develop and validate a multi-step kinetic model that predicts the pyrolysis behaviour and reaction mechanism of poplar wood (PW) pellet with different contents of PVC (0, 1, 5, 10, 100 wt%). Using data from thermogravimetric analysis of the pellets at heating rates of 5, 10 and 20 °C/min, we determined the apparent kinetic parameters by combining Fraser-Suzuki deconvolution, isoconversional methods and master plot procedures. Our model fitted the experimental data well with a deviation of less than 4.5%. Our results show that the addition of 1 wt% PVC to PW decreases the activation energy of hemicellulose and cellulose pyrolysis in PW from 136.3 to 101.6 kJ/mol and from 216.7 to 108.2 kJ/mol, respectively. This demonstrates the importance of acid hydrolysis reactions between the cellulosic fibres of PW and HCl released from PVC dehydrochlorination. Furthermore, we found that a nucleation and growth mechanism best represents the rate-limiting interactions between PVC and PW, which we linked to the formation of metal chloride crystals from acid-base reactions between HCl and PW minerals. Our kinetic model is an improvement of current models for the co-pyrolysis of wood and PVC, and can be readily used in a reactor-scale model of a pyrolyser or gasifier due to its relative simplicity.

In this paper, gas permeability studies were performed on materials based on natural rubber/acrylonitrile butadiene rubber blends and nanoclay incorporated blend systems. The properties of natural rubber (NR)/nitrile rubber (NBR)/nanoclay nanocomposites, with a particular focus on gas permeability, are presented. The measurements of the barrier properties were assessed using two different gases—O2 and CO2—by taking in account the blend composition, the filler loading and the nature of the gas molecules. The obtained data showed that the permeability of gas transport was strongly affected by: (i) the blend composition—it was observed that the increase in acrylonitrile butadiene rubber component considerably decreased the permeability; (ii) the nature of the gas—the permeation of CO2 was higher than O2; (iii) the nanoclay loading—it was found that the permeability decreased with the incorporation of nanoclay. The localization of nanoclay in the blend system also played a major role in determining the gas permeability. The permeability of the systems was correlated with blend morphology and dispersion of the nanoclay platelets in the polymer blend.

International audience; Although work has been done to understand the sintering behavior and properties of Municipal Waste Incinerator Bottom Ashes to produce sintered (Bethanis et al. in Ceram Int 28:881–886, 2002; Cheeseman et al. in Resour Conserv Recycl 43:147–162, 2005; Bourtsalas et al. in Waste Manag 45:217–225, 2014; Taurino et al. in J Eur. Ceram Soc 37:323–331, 2017) or sinter-crystallized (Schabbach et al. in J Non Cryst Solids 357:10–17, 2011; Barbieri et al. in J Non Cryst Solids 354:521–528, 2008) ceramics, most of the trials reported in the literature focuses on the use of extensively milled bottom ashes powders (particle size around 1–50 µm), using processes that might not be easily transferable to industrial production at reasonable cost, and producing small cylinders with uniaxial compression technique on powders. This paper summarizes the development process of an extruded ceramic material made of gross-milled bottom ashes and waste clay, designed to be easily mass-produced using production capacities available in the building bricks industry, to be used as a high-temperature thermal energy storage material, which represents an alternative to the petrurgic ceramic previously developed for this application (Py et al. in J Sol Energy Eng 133:031008, 2011; Kere et al. in Int Conf Eng Waste Biomass Valoris, Porto, 2012; Py et al. in Stockage de l’ énergie: énergie thermique, stockage thermique haute température). Post-treated incinerator bottom ashes from a commercial incinerator has been collected, characterized and processed to form ceramic materials, using clay as a binder. Ashes were milled, dried, and mixed with various amounts of an illitic clay (produced as washing mud by a quartz quarry) prior to extrusion (cylindrical pellet) and firing at different temperatures, ranging from 1100 to 1120 °C. The sintered samples have been characterized in terms of density, mechanical strength, thermal capacity and thermal conductivity. Their mineral structure has also been studied. This work follows a study on the feasibility about the production of MWIBA based slabs with uniaxial compaction, and can be seen as an improvement regarding the shaping of the green bodies, more compatible with thermocline thermal energy storage process. The resulting sintered ceramics exhibit interesting properties such as relatively high mechanical resistance and low thermal conductivity, along with moderate density. These properties allow envisioning the use as filler material for thermocline thermal storage systems, especially considering the simplicity of the production process, relying on dry gross milling (jaw-mill), and firing at a temperature reachable within the building bricks and tiles industry. Production of adequate pieces to be used as thermal storage media seems however more relevant, the small size limiting the impact of sintering heterogeneities (formation of black bodies due to high content in fluxing agents like sodium and potassium).

International audience; Hydroxyapatite [HAP, (Ca10(PO4)6(OH)2)] is an emerging catalytic support possessing exciting features such as high thermal and mechanical strength, chemically stable with low water solubility along with tunable porosity and acid-basic character. Despite of these interesting characteristics, it has not yet been investigated in Fischer-Tropsch (FT) synthesis. Herein, for the first time, HAP-supported cobalt catalysts (Co/HAP) prepared by conventional incipient wetness impregnation method were examined in the FT synthesis process. The catalytic performance of these catalysts was compared with alumina-supported cobalt catalysts (Co/Alumina). HAP support was found to exhibit considerably less acid-site density, consequently, reducing detrimental interactions of the support with cobalt precursors leading to hardly reducible Co species that are generally observed with its alumina counterpart. Co/HAP catalysts exhibit relatively larger Co particle sizes (~9 nm versus ~6 nm, as observed from TEM analysis) and better Co reducibility when compared to its counterparts on alumina. FT synthesis at 20 bar, 220 °C and H2/CO = 2.1 showed that the CO conversion was higher on the catalysts (10 wt% Co loading) using HAP as a support material when compared to alumina. Under different testing conditions (220 or 230 °C) using the Co/HAP catalyst, the C5+ selectivity was in the range of 82–88%, whereas the methane selectivity was about ~10%.

International audience; Ni-based catalysts were prepared using two hydroxyapatites (Ca-HA1, SBET = 7 m2/g and Ca-HA2, SBET = 60 m2/g) with different physico-chemical properties. The objective of the study was to evaluate the performance of these two materials as promising supports for dry reforming reaction (DRM) as well as to investigate the influence of different process parameters, such as temperature, pressure, time and catalyst pretreatment on the performance of these two catalysts. Thermodynamic calculations were performed to determine the conditions that would limit solid carbon deposit and favor the reactants conversion. Then, an experimental parametric study was carried out to investigate the impact of the temperature, pressure, catalyst pretreatment and support thermal treatment on the catalysts performance. The results showed that the catalyst pretreatment allowed the reduction of the nickel particles in a higher extent, which resulted in better catalytic performance when compared to the catalysts without pretreatment. High temperatures around 700 °C and low pressures around 1.6 bar were required to attain high CH4 and CO2 conversions around 70–80% as well as high H2 and CO selectivity around 90% for 90 h of time on stream. In all cases, Ni/Ca-HA2 catalyst presented better catalytic performance than Ni/Ca-HA1 due to the presence of smaller nickel particles (10–20 nm), stronger basicity, higher density of basic sites (0.23 mmol g−1) as well as higher specific surface area (SBET = 60 m2/g) of the Ca-HA2 support. Ni/Ca-HA2 catalyst was highly active (initial methane conversion: 75%) and relatively stable during 90 h of TOS and its catalytic behavior was comparable with the performance of Ni-based catalysts prepared with conventional supports reported in the literature.

International audience

International audience

International audience; In this study, the combination of capture mechanisms in ceramic water filters (doped with hydroxyapatite and alumina) was considered for the removal of contaminants from drinking water. It was found that hydroxyapatite and alumina were conserved during the firing process of the ceramic water filters up to 950°C. The nanopores resulting from the conservation of the additives increased the specific surface area of the ceramic water filters from 3.7 to 21.0m2·g−1. On the other hand, the microscopic pores associated with the processing of the ceramic water filters (i.e., pressing and drying) and the combustion of the sawdust reduced the filtration time from 24 to 4 h. The efficiency of the resulting filters in removing bacterial, chemical, and viral contaminants from water was investigated using E. coli, fluoride, and MS2 as model contaminants. The contaminants were found to be captured from water by trapping in the pores, substitution in the hydroxyapatite, and adsorption on the surface of alumina. Hence, the ceramic water filters incorporating hydroxyapatite and alumina combined the different capture mechanisms. They had an efficiency of 99.998%, 99.970%, and 99.450% in the removal of bacterial, chemical, and viral contaminants, corresponding to log reduction values (LRVs) of 4.69, 3.47, and 2.26, respectively.

International audience; A high-temperature air/ceramic thermocline packed-bed heat storage pilot was designed and built to measure the effects of operating parameters and quality of the heat resource on its performance, with a horizontal duct of square section. The influence of inlet air flow rate during the discharging phase and the impact of a degraded inlet heat resource during the charging phase were studied. The results revealed that the horizontal orientation of the bed didn’t generate a thermal radial gradient. Results also show that the overall cycle efficiency is weakly affected by the changes in the operating conditions. Thermocline heat storage is surprisingly well-suited to managing resource instabilities. It forms a robust, flexible high temperature storage system applicable for industrial use to recover and deliver erratically produced waste heat.

International audience; The study presented an innovative way to dispose and upgrade heavy metal (HM) contaminated biomass by solar pyrolysis. Pyrolysis of raw and HM (Cu and Ni) impregnated willow wood was performed in a solar reactor under different temperatures (600, 800, 1000, 1200, 1400 and 1600 °C) and heating rates (10 and 50 °C/s). The combined effects of HM and heating parameters (temperature and heating rates) on solar pyrolysis products were investigated. The results indicated that a threshold temperature of 1000 °C was required in impregnated willow pyrolysis to make sure copper and nickel catalytic effects on promoting the cracking and reforming reactions of tar. It led to the gas yields from copper or nickel impregnated willow pyrolysis at 1200 °C increased by 14.76% and 34.47%, respectively, compared with that from raw willow. In particular, the H2 and CO production from nickel impregnated willow were higher than those from raw willow (10.30 and 12.16 mol/kg of wood versus 6.59 and 8.20 mol/kg of wood) in case of fast pyrolysis (50 °C/s). Under heating rate of 10 °C/s, H2 and CO yields from only nickel impregnated willow increased compared with that from raw willow. Solar pyrolysis of HM contaminated biomass is a promising way to produce valuable syngas.

International audience; Waste-to-Energy (WtE) has started playing an increasingly important role in the recovery of energy from municipal solid waste (MSW). A number of WtE technologies are being developed. However, selecting a more environmentally sustainable option is difficult due to data limitation and methodological inconsistencies. Using life cycle assessment (LCA) as a tool, this paper aims to identify key factors influencing the potential environmental impacts of four representative WtE technologies, namely the incineration (S1), pyrolysis (S2), gasification (S3), and gasification coupled with ash melting (S4). The systems are constructed using inventory data based on on-site operation of several industrial-scale reference plants. A comprehensive sensitivity analysis is conducted, assessing a range of critical input parameters, processes, operating conditions and modelling assumptions. The results demonstrate that all analysed WtE systems exhibit environmental benefits (i.e. negative environmental impacts) for most of the impacts, while S3 seems to be more optimal due to an intermediate syngas cleaning process, which results in both reduced emissions and increased energy recovery. Parameters driving the environmental impacts are energy recovery efficiency, feedstock variability, NOx and CO2 emissions at stack, and recycling of metals. Moreover, the overall ranking of different WtE systems is strongly dependent on operating conditions, such as effectiveness of the air pollution control process, utilization pathway of pyrolysis char, and to a lesser extent, bottom ash management (landfill or recycling). The LCA modelling conditions, such as substituted source of electricity, choice of functional unit and time frame are also shown to significantly affect the quantified environmental performance. Finally, the study highlights the directions, towards which, efforts should be focused throughout all stages of each WtE technology to obtain further improvements.

International audience; Over the past few decades, the sharp rise in post-consumer plastic and biomass waste has resulted in an ever growing challenge to treat such waste sustainably. Co-pyrogasification of plastics and biomass mixtures, as opposed to separately converting these waste streams, offers several advantages including an improvement in syngas quality and composition (H2/CO ratio) in relation to the desired application, and an easier reactor feeding of plastics. Furthermore, many studies have shown that co-pyrogasification promotes the conversion of waste to gas rather than char and tar. However, in order to achieve the desired product distribution or syngas composition, operating parameters such as the reactor temperature, equivalence ratio (air or oxygen), steam/fuel ratio and catalyst, have to be optimized. Thus, this paper aims to review literature studies on the co-pyrogasification of plastics and biomass by considering various aspects including the process principle, reactors, influence of feedstock characteristics and operating parameters on the products, as well as the synergies observed during the thermoconversion of plastics and biomass mixtures with some reference to coal mixtures when necessary.

International audience; Syngas production enhancement via catalytic methane cracking onto metal-loaded chars, with a specific focus on the activity of two inherent alkali and alkaline earth metals (AAEMs), Ca and K, was investigated. Chars produced from the gasification of poplar wood pellets were heated to 700°C in inert atmosphere and then tested as catalysts for methane cracking at 700°C. Methane is one of the most abundant biomass gasification by-product. The cracking of this component is relevant in increasing the syngas production and yield. The syngas production was increased by a factor 1.9 to 2.7 using metal-loaded chars. Results were explained by the catalytic effect of AAEMs on both the desorption of oxygenated functional groups and on the catalytic methane cracking. AAEMs promoted methane molecules combination with the active sites such as oxygenated groups available at the surface of the chars enhancing both H2 and CO production. It was observed that potassium loaded char (K-char) showed the best performance. The calcium-loaded char (Ca-char) was less efficient, due to a higher amount of silicon which interacted with calcium to form silicates. No synergetic effect was observed on the syngas production with the Ca+K_char.

International audience; Relevant literature which deals with the presence of metals during the catalytic pyrolysis of biomass is reviewed. Only those conditions where the metal was in intimate contact with the biomass components are included. Cellulose, hemicellulose and lignin all fuse during the early stages of pyrolytic heating and the dehydration and decomposition processes begin during this transition. Hemicelluloses such as xylan are more labile and difficult to isolate, whereas both cellulose and lignin produce mostly bio-oils when demineralised and flash pyrolysed. The dominant primary products from ‘pure’ cellulose are anhydrosugars as well as smaller oxygenates. Lignin gives aromatics based on the syringol and guiacol molecules. The alkali and alkaline earth metals are found to curtail the yield of bio-oil and modify product distribution, even in the low concentrations naturally found in biomass. All other metals act to catalyse cross-linking reactions, with the nickel and zinc most studied. The electropositivity of the metal tends to correlate with the extent of catalytic activity. The presence of metals causes little change to the production of gases, but more char is formed at the expense of liquids. If the aim of pyrolysis is bio-oil for fuel, prewashing of biomass to remove metals is beneficial.

National audience

International audience; The ever increasing public complaints arising from wastewater treatment plants (WWTPs) grow since sewerage treatment has been associated with nauseous odorous on account of the anaerobic decomposition process and emission. Various physical/chemical and/or biological methods were used for abating odours worldwide. Thus, an updated comprehensive review for the WWTP odor abatement technologies is urgently required. This study reviews the new achievements of odor abatement technologies (adsorption, chemical scrubbing, biofiltration, biotrickling, bioscrubbing, activated sludge diffusion) in WWTPs and then identifies a new aspect for the future studies. Overall, hybrid technologies (physical/chemical + biotechnologies) attract increasing attention since their highly reliable removal efficiency for various odorants, however, the high costs for investment and O&M (operation & maintenance) of the adsorption part and the complexity and variability of odorants are still the major challenging for wide engineering application and technological innovation. Thus, developing the cost-effective, environmentally friendly odor control technologies, like using the alum sludge (waterworks residue) based adsorbents/media, in terms of using “waste” for waste treatment, could be a highly promising prospect.

International audience; The catalytic activity of pyrolysis chars from bio-waste was investigated for the cracking of model tar compounds (ethylbenzene and benzene). Two pyrolysis chars were produced at 700 °C from (1) used wood pallets (UWP), and (2) a 50/50 dry% mixture of food waste (FW) and coagulation-flocculation sludge (CFS). Steam activation at 850 °C was used to study the influence of the porous structure. While coke deposition is known to be responsible for the deactivation of carbonaceous chars and metal catalysts during tar cracking reactions, the deactivation of complex materials such as bio-waste chars has scarcely been studied. For this reason, special attention was paid on the relationships between the physicochemical properties of the chars, the operating conditions, and the deactivation mechanisms. To this aim, the cracking tests were performed over a wide temperature range: 400–650 °C for the ethylbenzene cracking, and 850–950 °C for benzene cracking. After the ethylbenzene cracking tests at 650 °C, the characterisations performed with SEM, BET, FTIR and Raman revealed that coke deposition was responsible for the char’s deactivation. The high specific surface area of activated chars explained their higher catalytic activity, and mesoporous catalysts were proved to be more resistant to coke deactivation than microporous catalysts. For these reasons, the higher ethylbenzene conversion (85.8%) was reached with the activated char from food waste and sludge (ac.FW/CFS). For benzene cracking at higher temperature (850 and 950 °C), the chars from food waste and sludge (FW/CFS) were the most active catalysts, despite their deactivation by the melting, diffusion and sintering of the inorganic species. This original deactivation mechanism, reported for the first time, led to the formation of an inorganic layer composed of P and Ca species at the char surface, with some areas rich in KCl and NaCl. Non-activated char from food waste and sludge (c.FW/CFS) was surprisingly proved to be more resistant to deactivation by inorganic species than the activated char (ac.FW/CFS) during the benzene cracking tests at 950 °C. This extended catalytic activity was explained by the activation of the non-activated char (c.FW/CFS) with the CO2 contained in the syngas which simultaneously developed the porosity and created new available active sites. This study marks a step forward in the understanding of the relationships between the deactivation mechanisms, the physicochemical properties of the chars, and the cracking temperature. Finally, a proposal for process integration is presented to consider the possibility to valorise the chars as catalysts to decompose the tar generated in the same pyro-gasification process.

International audience; Dredging operations produce considerable quantities of materials, to be managed and this opens an opportunity for valorization in civil engineering. However, the contamination of the dredged sediments has become a major problem to solve. The major contaminants are heavy metals and organic compounds. This study focuses on the use of phosphoric acid (H3PO4) to stabilize heavy metals from sediments and destroy organic matter by calcination at 650 degrees C with a goal of using sediments in roadworks. Several studies have been conducted in this field. The stabilized materials obtained have been used in civil engineering. The main purpose of this work is to discuss the environmental behavior of marine sediment treated by phosphatation and calcination. Two types of phosphoric acids were used. The pH dependence leaching test has been used as the basic characterization to evaluate the effect of the type of phosphoric acid on the metals behavior in a valorization scenario. The standard leaching test and the Toxicity Characteristic Leaching Procedure (TCLP) were conducted as compliance tests. In regards of the obtained results, the environmental assessment has also shown a reduction in the availability of targeted heavy metals in alkaline environment whatever the type of acid used for treatment. This opens opportunities for co-valorization. (C) 2018 International Research and Training Centre on Erosion and Sedimentation/the World Association for Sedimentation and Erosion Research.

International audience; Turtle shells comprising of cortical and trabecular bones exhibit intriguing mechanical properties. In this work, compression tests were performed using specimens made from the carapace of Kinixys erosa turtle. A combination of imaging techniques and mechanical testing were employed to examine the responses of hierarchical microstructures of turtle shell under compression. Finite element models produced from microCT-scanned microstructures and analytical foam structure models were then used to elucidate local responses of trabecular bones deformed under compression. The results reveal the contributions from micro-strut bending and stress concentrations to the fractural mechanisms of trabecular bone structures. The porous structures of turtle shells could be an excellent prototype for the bioinspired design of deformation-resistant structures.Statement of SignificanceIn this study, a combination of analytical, computational models and experiments is used to study the underlying mechanisms that contribute to the compressive deformation of a Kinixys erosa turtle shell between the nano-, micro- and macro-scales. The proposed work shows that the turtle shell structures can be analyzed as sandwich structures that have the capacity to concentrate deformation and stresses within the trabecular bones, which enables significant energy absorption during compressive deformation. Then, the trends in the deformation characteristics and the strengths of the trabecular bone segments are well predicted by the four-strut model, which captures the effects of variations in strut length, thickness and orientation that are related to microstructural uncertainties of the turtle shells. The above results also suggest that the model may be used to guide the bioinspired design of sandwich porous structures that mimic the properties of the cortical and trabecular bone segments of turtle shells under a range of loading conditions.

International audience; Over the past few decades, the sharp rise in post-consumer plastic and biomass waste has resulted in an ever growing challenge to treat such waste sustainably. Co-pyrogasification of plastics and biomass mixtures, as opposed to separately converting these waste streams, offers several advantages including an improvement in syngas quality and composition (H2/CO ratio) in relation to the desired application, and an easier reactor feeding of plastics. Furthermore, many studies have shown that co-pyrogasification promotes the conversion of waste to gas rather than char and tar. However, in order to achieve the desired product distribution or syngas composition, operating parameters such as the reactor temperature, equivalence ratio (air or oxygen), steam/fuel ratio and catalyst, have to be optimized. Thus, this paper aims to review literature studies on the co-pyrogasification of plastics and biomass by considering various aspects including the process principle, reactors, influence of feedstock characteristics and operating parameters on the products, as well as the synergies observed during the thermoconversion of plastics and biomass mixtures with some reference to coal mixtures when necessary.

This work aims at demonstrating the possibility of producing 2-butanol from lignocellulosic biomass through a new thermochemical approach. The production of biobutanol was carried out using different lignocellulosic feedstock through a 3-step process: first the whole lignocellulosic biomass is hydrolyzed under acid catalyst to produce levulinates, then the levulinates go through decarboxylation to produce 2-butanone which is, in a final step, reduced to produce of 2-butanol. The experimental conditions for the first two steps of the process were optimized using the response surface methodology (RSM). The latter could represent an opportunity for the production of economical second-generation butanol without having to go through the classical pathway requiring the production of sugar prior to microbial conversion. The authors are grateful for the financial support to MITACS (Grant number ITO3931) and for the grant to the Natural Sciences and Engineering Research Council of Canada (NSERC, Grant number EGP 487206-15).

International audience; Solar pyrolysis of cotton stalk was carried out in a molten salt reactor heated by 4 kW solar simulator. The effects of pyrolysis temperature and mass ratio of molten salt to biomass on pyrolysis products properties were investigated. The use of molten salt as pyrolysis media increased gas yield. At 850 °C, the gas yield (mainly of CO and H2) continued to rise from 41.35 wt% to 82.57 wt% when mass ratio of molten salt to cotton stalk increased from 0 to 10. Pyrolysis in molten salt significantly decreased bio-oil acids and phenols, while increased aromatics among pyrolysis temperature range of 450–850 °C. There was positive correlation between the increased content of aromatics and mass ratio of molten salt to cotton stalk (from 0.5 to 10). The bio-char carbon content showed a general decreasing trend while oxygen, BET surface area and pore volume increased with using molten salt as pyrolysis media. Bio-char obtained from CS1MS5 pyrolysis at 850 °C had the highest BET surface area of 972.57 m2/g and the biggest total pore volume of 0.6203 cm3/g. High quality pyrolysis products with more uniform chemistry suggest catalytic reactions occur inside the solar reactor due to the intermediates degradation with molten salt.

Review; International audience; The steam gasification and co-gasification reactivity and kinetics of coconut shells, oil palm shells and bamboo guadua were studied from an isothermal thermogravimetric analysis, with temperatures ranging from 750 °C to 900 °C, and steam partial pressures from 3 to 10 kPa. In the analyzed experimental range, inorganics were identified as the most influential parameter in biomass reactivity and kinetics. Accordingly, a new modeling approach is proposed to predict the gasification behavior of lignocellulosic agrowaste based on their inorganic composition. A good agreement between the experimental and modeled data was found, showing that the proposed approach is suitable for the description and prediction of the gasification behavior of biomasses with different macromolecular structure and within a wide range of inorganic composition, and H/C and O/C ratios near 1.5 and 0.8 respectively. This kinetic model could constitute a valuable tool for reactor design and scale-up of steam gasification facilities using tropical lignocellulosic feedstocks.