6th International Conference on Sustainable Solid Waste Management 13-16 June 2018 Naxos, Greece Unravel the structure and reactivity of wood and biowaste biochars Professor Ange Nzihou RAPSODEE Research Center, CNRS , IMT Mines Albi, France
Research field: Alternative feedstocks to energy and multifunctional materials My group: 16 persons (4 faculties + 8 PhDs and 4post-docs) CO 2 + H 2 O, (- Hr) CHP Steam Gas Electricity reforming Combustion CH 4 + H 2 O → CO + 3 H 2 ( 750-1000 °C; Excess air) Heat Fuel cell Wood Pyrolysis Gasification (400 – 800 °C; Syngas H 2 Biochar Cleaning Inert atm) ( >800 °C; (CO, H 2 ) Biomass,Waste Atm: O 2 , H 2 O,CO 2 ) and/or separation HCl, Metals MSW Catalytic synthesis (Municipal Solid Waste) Biocommodities, MeOH, EtOH Refinery & Fuels Food Waste Multi-functional materials for: • Environment Bio-Oil / Tar • Composites RDF ( Refuse Derived Fuel) • Energy SRF (Solid Recovered Fuel) • Chemistry Paper, plastic, chips of wood 2 • Agronomy C&IW (Commercial & Industrial Waste)
OUTLINE I. Biochar production and utilisation II. Biochar characterisation and properties III. Some applications as ceramics for environmental remediation IV. To take home 3
I. Biochar production and utilisation Thermochemical conversion – range of applications 600 - 900°C 250 - 280°C 300 - 550°C 100- 150°C Torrefaction MT pyrolysis HT pyrolysis & Drying gasification enables chemical conversion of a mild form of pyrolysis dedicated only A dehydration with the release of light conversion most of the feedstock into products like biomass, plastic, or rubber for biomass conversion. Torrefaction hydrocarbons methane-rich syngas which can be into a solid, liquid or gas phase. Enables leads to obtaining dry product with valorized into energy by using it CHP valorization to biooil and biochar. Yield higher energy content. Main product is unit or steam boiler. Yield of syngas of biooil ranges from 30 to 60%. biocoal - yield between 70 and 80% ranges from 50 and 95% Yield of biochar 25 to 35% BIOOIL, BIOOIL, GAS GAS BIOCOAL BIOCOAL SYNGAS SYNGAS BIOCHAR BIOCHAR VOC CO+H 2 H 2 O H v(H2O) = 2.3 MJ/kg at 100°C 13 < Biooil (MJ/kg) < 27 8 < Biocoal (MJ/kg) < 22 12 <Syngas (MJ/kg) < 20 LHV (Low heating value): 4 10 < Biochar (MJ/kg) < 32 Reference: LHV H2= 120 MJ/kg LHV CH4= 50 MJ/kg LHV MSW=10 MJ/kg
I. Biochar production and utilisation Energy Fuel cells photovoltaic Some current utilisations Supercapacitors Chemistry Catalyst Adsorbent Water treatment Environment Carbon fibers Carbon sequestration Nanotubes CO 2 Storage Sensors Agronomy Water retention Plant nutrients Soil conditioner Composites Reinforcing materials Other uses in polymer composites. Biomedical use Pharmaceutical 5 5 Biocomposites
II. Biochar characterisation and properties Raw biomass composition Oil Palm Shell (OPS) Coconut Shell (CS) Bamboo (BG) Three tropical biomasses were selected from different agro wastes Macromolecular composition Inorganic composition 60 2,0 2.0 Composition [wt%] 50 Composition [wt%] 1,5 1.5 40 1.0 1,0 30 20 0.5 0,5 10 0 0,0 0 Al Ca Cr Cu Fe K MgMnMn Ni P Si Zn Cellulose Hemicellulose Lignin OPS BG CS OPS BG CS Oil palm shells and Coconut shells are endocarps with high lignin content Si is the most important inorganic constituent of Bamboo guadua K is the most important inorganic constituent of Coconut shells 6 L.M. Romero Millan, NZIHOU A., F.E. Sierra Vargas., BioEnergy Research, 10, 832-845, 2017
II. Biochar characterisation and properties Chemical Physical properties properties textural carbon matrix O- groups minerals properties • Fourier • X-ray • BET analysis • Raman transformed infra fluorescence spectroscopy Specific (XRF) red (FTIR) Carbon structure surface area Elemental analysis distribution Nature of O- • Transmission Porosity containing groups • X-ray Electron • Temperature diffraction (XRD) Microscopy (TEM) Programmed Structure Desorption (TPD) •X-Ray • ESEM analysis Tomography Quantification Distribution Nanostructure 7
II. Biochar characterisation and properties High Resolution TEM spectra Raman spectrum Disordered structure 1 0.9 BG-750°C 0.8 Normalized intensity Mean pore diam: 0,7 nm 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 800 1000 1200 1400 1600 1800 2000 Raman shift (cm ‐ 1 ) • Raw biochar complex carbon containing: - Ordered structure - Disordered structure 8
II. Biochar characterisation and properties BG- BIOCHAR 750°C HRTEM Porosity Graphene fringes
II. Biochar characterisation and properties BIOCHAR 400°C Bright field TEM - nanopores 1 7 . 9 0 n m 1 7 . 9 0 n m 1 8 . 7 5 n m 1 8 . 7 5 n m 3 4 . 4 5 n m 3 4 . 4 5 n m 1 3 . 7 1 n m 1 3 . 7 1 n m 1 8 . 6 0 n m 1 8 . 6 0 n m 1 6 . 0 1 n m 1 6 . 0 1 n m 1 6 . 9 0 n m 1 6 . 9 0 n m 1 3 . 9 0 n m 1 3 . 9 0 n m 2 0 . 4 7 n m 2 0 . 4 7 n m 1 2 . 1 5 n m 1 2 . 1 5 n m 1 4 . 2 2 n m 1 4 . 2 2 n m 2 0 . 0 1 n m 2 0 . 0 1 n m 1 8 . 2 2 n m 1 8 . 2 2 n m 2 1 . 0 1 n m 2 1 . 0 1 n m 1 9 . 0 3 n m 1 9 . 0 3 n m 4 7 . 2 0 n m 4 7 . 2 0 n m 2 5 . 5 9 n m 2 5 . 5 9 n m 5 0 n m 5 0 n m
II. Biochar characterisation and properties Surface functions determination strong weak acids acids carboxylic anhydride lactone acid acid TPX (R, O, D) quinone phenol pyrone TPR : reductible species 00 TPO : oxidable species TPD : active sites Chimisorption : dispersion of metals Titration : acidic and basic sites bases Temperature Programmed Desorption (TPD): Thermal desorption spectrometer 11 J.L. Figueiredo et al.,Carbon (1999) / I. Salame ,J. of Colloid and Interface Science (2001)
II. Biochar characterisation and properties Surface functions determination Temperature Programmed Desorption (TPD)- Gas chromatography Biochar from poplar wood ether 0.07 0.175 CO CO 2 anhydride 0.06 0.15 acid Concentration (%) Concentration (%) phenol 0.05 0.125 peroxide lactone 0.04 0.1 carboxylic hydroxyl quinone 0.03 acid 0.075 0.02 0.05 pyrone anhydride acid 0.01 0.025 0 0 0 200 400 600 800 1000 0 200 400 600 800 1000 Temperature (°C) Temperature ( ° C) Bases Strong acids Weak acids 12 M. Ducousso, E. Weiss-Hortala, A. Nzihou, M.Castaldi. Fuel 2015, 159, 491-499
III. Some applications as ceramics for environmental remediation Clay biochar Composites 50 • Filters for polluted gas Specific surface area (m²/g) Clay + Biochar • Filters for effluents treatment 40 • Sensors for pollutants removal Wood biochar-750°C 30 20 10 0 0 5 10 15 20 Filter Addition rate (%) Polluted gas Polluted gas 13
III. Some applications as ceramics for environmental remediation Wastewater treatment: Denitrification Sample Total porosity Open porosity Permeability Specific surface (%) (vol.%) (mD) area (m 2 /g) CWF 34 27 23 0.9 CWF+ 20wt.% 57 52 43 194.7 biochar Data obtained using water absorption (porosity), mercury intrusion porosimetry (permeability) and nitrogen adsorption analysis using the BET method (specific surface area)) Contaminants (nitrate), adhesion forces and capture efficiency of the ceramic water filter (CWF). 180 7 Capture of nitrate (mg/g) 160 6 Adhesion force (nN) 140 5 120 4 100 80 3 60 2 40 1 20 0 0 CWF CWF CWF CWF+20wt.%Biochar CWF+ 20 wt.% Biochar CWF+20wt.%Biochar Data obtained using AFM, chromatography (IC), ICP-MS 14 P.M. Nigay et al. J. of Environ. Eng., 2017
III. Some applications as ceramics for environmental remediation Wastewater treatment: Removal of heavy metals Dependence of the cadmium capture efficiency of the clay ceramic 15 P.M. Nigay, A. Nzihou et al. J. of Environ. Eng., 2017
IV . To take home Carbonaceous materials such as biochar can derive from renewable resources such as Biomass and Biogenic waste Can be used as a product itself or as an ingredient within a blended product, with a range of potential applications as ceramics Renewable nature Cost effectiveness Tunable: reactivity, thermal and mechanical stability Well adapted for developing Countries BIOCHAR: A tunable and multi-functional material 16
ACKOWLEDGEMENTS Thank you to my research group and international colleagues: Thank you to Maria and Kostas for the invitation and for the PARTICULAR CARE.
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