Ange Nzihou

• IMT Mines Albi

The approach aiming at replacing fossil-based carbons by graphitic biocarbon has gained momentum in applications from environmental remediation to battery electrodes and supercapacitors, reducing their environmental impact. To address biocarbon high production temperature and energy consumption, this work uses lignin, a renewable feedstock, and con...

The present invention relates to an extract obtained from lignocellulose biomass, a process for manufacturing said extract, and uses thereof. In particular, the present invention relates to an extract obtained from a lignocellulose biomass comprising cellulose and at least 1%, preferably at least 5% by weight of the total weight of the extract, of...

Unprecedented efforts are being deployed to develop hydrogen production from bioresources in a circular economy approach, yet their implementation remains scarce. Today’s Challenges are associated with the shortage in the value chain, lack of large-scale production infrastructure, high costs, and low efficiency of current solutions. Herein, we repo...

Hydrothermal liquefaction (HTL) is an emerging process that converts organic waste into a liquid biofuel, named biocrude, by means of water at elevated temperature and pressure. Recently, it became attractive for potentially replacing anaerobic digestion (AD) for municipal sludge treatment. This study assessed carbon and energy recovery from sludge...

Hydrochar from hydrothermal liquefaction (HTL) of municipal sludge is often seen as waste. Initially, acidic leaching has been performed on hydrochar to recover phosphorus. This study evaluated the resulting hydrochar as solid fuel, thus achieving zero waste for integrating HTL into wastewater treatment plants. The effects of various leaching condi...

A recent study has shown that highly crystalline graphene-based materials can be obtained from poorly organized carbon precursors using calcium as a non-conventional catalyst. XRD and TEM analyses of calcium-impregnated cellulose and lignin biochars showed the formation of well-ordered graphenic structures (Lc > 7 nm, d002 < 0.345 nm) above 1200 °C...

Hydrothermal liquefaction has the potential to exploit resources from municipal sewage sludge. It converts most organics into a liquid biofuel (biocrude), concentrates P in the solid residue (hydrochar), and consequently enables its efficient recovery. This study thoroughly evaluated the effects of extraction conditions on P and metal release from...

Biomass pyrolysis within the alkaline molten salt is attractive due to its ability to achieve high hydrogen yield under relatively mild conditions. However, poor contact between biomass, especially the biomass pellet, and hydroxide during the slow heating process, as well as low reaction temperatures, become key factors limiting the hydrogen produc...

Hydrogen is called to play a crucial role in decarbonizing different sectors by meaningfully reducing their emissions. Hydrogen production from biomass and biowaste has recently gained momentum due to the high availability of the resource and maturity of thermochemical conversion technologies. However, hydrogen monitoring and purification is requir...

Fired clay ceramics are promising materials for TES, thanks to their thermal stability, availability worldwide, low cost and easy shaping and handling. However, their thermo-physical and thermo-mechanical properties have to be improved. For the first time, clay-phosphate ceramics, with synthetic calcium hydroxyapatite (TCP, Ca10(PO4)6(OH)2) as addi...

Pyrolysis of algae in molten carbonates driven by concentrated solar energy is proposed as an economical and environmentally friendly method to obtain capacitive carbon for supercapacitors. The effects of molten carbonates on pyrolysis process and electrochemical performance at different temperatures (800, 850 and 900 °C) are investigated. Na2CO3–K...

This paper deals with steam gasification kinetics of cellulose pulp extracted from biomass with on the focus silicon effect. Isothermal TGA tests were performed under various operating conditions. The gasification reactivity increased with increasing temperature and steam pressures. The reactivity of cellulose pulp biochar was 3 times lower than th...

Understanding the mechanism of iron‐catalyzed graphitization of biomass is an important step for the large‐scale synthesis of green graphene. Although iron is known to be the most active transition metal for the catalytic graphitization of cellulose‐derived biochar, the direct effect of the iron molecular structure on the formation of highly graphi...

Pyrolysis of lignocellulosic biomass (hard carbon) produces poorly graphitic biochar. In this study, nano-structured biochars were produced from microcrystalline cellulose using calcium as a non-conventional catalyst. Calcium is abundant, environmental-friendly and widely accessible. Graphitization of calcium-impregnated cellulose was carried out a...

Hydrothermal liquefaction (HTL) is a promising technique for renewable biofuel (biocrude) production from municipal sludge. However, its solid byproduct, hydrochar, requires sustainable management for further resource recovery and pollution control. This study comprehensively assessed the properties, environmental influences, and possible utilizati...

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...

4-hydroxy benzaldehyde (H) and vanillin (G) are typical primary pyrolysis products of β-O-4 lignin dimers with key functional groups that affect the secondary reactions of lignin pyrolysis. In this study, the pyrolysis heavy components from these two lignin monomers were analyzed and identified at molecular scale for the first time with Fourier tra...

The treatment and disposal of waste biomass and plastics are of great importance to achieve both waste management and resource recycling. In this work, pyrolysis of biomass and plastic blends were investigated to identify the influence of temperature and in situ CaO addition on the production of hydrogen-rich, HCl-free, and low tar content fuel gas...

Cellulose, lignin and their mixture were pyrolyzed at 500–700 °C for 60 s and 90 s to investigate the influence of cellulose-lignin interaction on the evolution of biomass pyrolysis bio-oil heavy components with temperature and reaction time. Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) and Fourier transform infrared spec...

The treatment of significant amounts of municipal sewage sludge requires novel and efficient technologies. This study evaluated hydrothermal liquefaction as a means to sustainably convert sludge waste into a renewable energy source – biocrude, which can mitigate both environmental and energy-related challenges. Response surface methodology was empl...

As one of the major urban waste streams, municipal sludge has been recognized as complementary phosphorus (P) sink that can be used to mitigate the global P scarcity. However, recovering P directly from municipal sludge is inefficient (< 50% of total input) and expensive due to its large volume but low concentrations of P. Moreover, municipal sludg...

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 pyro...

The application of biomass-derived renewable materials has generated great interest in recent research works. Among many such biopolymers, nanocellulose has become the leading topic in the sphere of sustainable material owing to the outstanding mechanical, chemical and thermal properties along with non-toxicity, surface functionality, ease of modif...

This work is part of the VABHYOGAZ (valorization of biogas into hydrogen) program, which targeted the industrial deployment of hydrogen production from biogas in France. To-date, different processes of methane reforming, such as steam reforming of methane (SRM), dry reforming of methane (DRM) and tri-reforming of methane (TRM), have been studied in...

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...

To identify the performance and mechanism of variant molten salts during biomass pyrolysis in molten salt, the thermogravimetric and differential scanning calorimetry (TG-DSC) analyzer, fixed-bed reactor and thermodynamic equilibrium simulation were applied to study the thermal melting characteristics and stability of molten salt as well as the sel...

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...

Waterworks sludge refers to the inevitable suspended and dissolved solids produced during the water purification process when producing tap water where Al-salt and/or Fe-salt are used as coagulant worldwide. Waterworks sludge is dewatered and the resultant cakes have been treated as “waste” for landfill as their major final disposal solution for a...

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-chemi...

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...

A batch crystallizer in a pilot setup was utilized to produce di-amonium phosphate (DAP) crystals for purification studies by desing of experiments using a fractional experimental design 2 5-2. After purification, the selling price of DAP is increased five fold, which is the incentive for this optimization. Purified DAP is also used in the pharmace...

Raw calcium phosphate obtained by adding phosphoric acid to phosphate ore yields industrial triple super phosphate (TSP), consisting of calcium phosphate that contains many impurities. TSP was dissolved in a minimum amount of water, filtered to remove insoluble compounds and evaporated to dryness. This produced monocalcium phosphate monohydrate of...

Monocalcium phosphate monohydrate (MCPM) was obtained by water extraction of triple superphosphate. The solubility of MCPM is 783.1 g/L, and is entirely soluble. Saturated MCPM solution dissociates into free phosphoric acid and monetite (CaHPO 4), but evaporation to dryness by spray drying forms MCPM during crystallization. Complete characterizatio...

Raw calcium phosphate obtained by adding phosphoric acid to phosphate ore yields industrial triple super phosphate (TSP), consisting of calcium phosphate that contains many impurities. TSP was dissolved in a minimum amount of water, filtered to remove insoluble compounds and evaporated to dryness. This produced monocalcium phosphate monohydrate of...

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 e...

Additional options for the sustainable treatment of municipal sludge are required due to the significant amounts of sludge, high levels of nutrients (e.g., C, N, and P), and trace constituents it contains. Hydrothermal processing of municipal sludge has recently been recognized as a promising technology to efficiently reduce waste volume, recover b...

Algae pyrolytic bio-oil contains a large quantity of N-containing components (NCCs), which can be processed as valuable chemicals, while the harmful gases can also be released during bio-oil upgrading. However, the characteristics of NCCs in the bio-oil, especially the composition of heavy NCCs (molecular weight ≥200 Da), have not been fully studie...

Fischer-Tropsch catalyst preparation parameters, such as cobalt precursor and impregnation solvent, determine structure and in fine catalytic performances of Co-based catalysts. Co particles of 3-7 nm mean size were prepared by incipient wetness impregnation on surface-oxidized CNT. In this work the crucial impact of the chemistry operating between...

A novel alum sludge-based odor-gas aerated vertical flow biofilter (Al-OAF) was developed, which aims to removal the pollutants in wastewater and simultaneously to eliminate H2S generated from wastewater treatment facility. Three lab-scale parallel columns were operated in batch model while intermittently aerated with 200 ppm H2S (Al-OAF), air (Al-...

The solar gasification system (SGS) and traditional system are modeled by Aspen Plus. And their energetic, economic as well as ecologic (3E) performance are compared. The effects of different feedstocks and Direct Normal Irradiance (DNI) to the productivity and efficiency of SGS are also carried out. The results show that a biomass-based, solar-ass...

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 dep...

An array of highly conductive, lightweight and flexible cellulose nanopapers as effective attenuators of electromagnetic radiations within 8.2–12.4 GHz (X band) were formulated via in situ polymerization of pyrrole monomers on to cellulose nanofibers (CNFs). It is quite obvious that the free hydroxyl groups on the surface of CNFs facilitate the for...

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, paper...

By 17 October 2020, the severe acute respiratory syndrome coronavirus (SARS-CoV-2) has caused confirmed infection of more than 39,000,000 people in 217 countries and territories globally and still continues to grow. As environmental professionals, understanding how SARS-CoV-2 can be transmitted via water and air environment is a concern. We have to...

Lignocellulosic agrowastes are one of the most abundant and inexpensive bioresources on earth. However, they comprise a wide range of materials with different organic and inorganic composition that may influence their performance in energy applications. Here, we analyze the impact of inherent inorganics on the steam gasification performance of bior...

The design of composite materials using environmentally compatible materials and adopting sustainable preparation techniques is very necessary for a better environment. The present study is a step towards developing an environmentally friendly alternative to foam-based composites. The aim of the study is to understand the effect of natural fibers f...

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...

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...

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-sit...

Modeling approaches are generally used to describe mercury transformations in a single step of flue gas treatment processes. However, less attention has been given to the interactions between the different process stages. Accordingly, the mercury removal performance of a full-scale solid waste incineration plant, equipped with a dry flue gas treatm...

Levulinates are used as oxygenated fuel additives or as blending components in biodiesel. A metal salt was used for the direct conversion of real biomass, ie. softwood bark, to produce methyl levulinate (ML) and levulinic acid (LA). The experimental data were analyzed through response surface methodology (RSM), using a central composite design (CCD...

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,...

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 assessme...

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 u...

Solar pyrolysis of raw and heavy metals (HMs) impregnated willow was performed at different temperatures (600, 800, 1000, 1200, 1400 and 1600 °C) with heating rate of 50 °C/s. CHNS, ICP-OES, SEM-EDX and BET were employed to investigate the effects of temperature and HMs contamination on char properties. The results indicated that a more ordered and...

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 i...

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) nan...

In this work, the direct production of levulinates from cheap residual lignocellulosic biomass was performed using an affordable homogeneous catalyst. A central composite design (CCD) using the response surface methodology (RSM) was applied to analyze the effects of the four selected factors (acid concentration, temperature, α-cellulose content, an...

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. T...

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 literatu...

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 pet...

This work is devoted to the removal of H2S 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 colum...

In this study, a comprehensive assessment of doped ceramic water filters (doping with hydroxyapatite and alumina) was conducted for potential application in household water treatment. The efficiency/reliability was assessed via statistical data analysis and normal distributions. It was found that the doped ceramic water filters had high porosity (6...

This paper firstly reported a systematic study of using alum sludge (waterworks residue) for H2S adsorption. Various trials were performed at ambient temperature in a fixed bed column to study the effects of H2S flow rate, sorbent bed depth on the alum sludge adsorption efficiency of H2S. The Breakthrough Curves were simulated by the Thomas model,...

The dry reforming of methane over hydroxyapatite‐ and alumina/magnesia (commercial Pural MG 30)‐supported nickel catalysts was investigated. The catalytic performance of the catalysts prepared with fresh supports highly depended on the basicity, the metal‐support interaction, and the metal particle size. Calcination of the supports at 1200 °C for 5...

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 literatu...