Sequestro di CO 2 come effetto secondario di una tecnologia di carbonatazione di ceneri leggere - Elza Bontempi - Desarc-Maresanus
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Sequestro di CO2 come effetto secondario di una
tecnologia di carbonatazione di ceneri leggere
Elza Bontempi
INSTM and University of Brescia
elza.bontempi@unibs.it
Outline Azure Chemistry approach Rendering project: recovery of fly ash from co-combustion of sewage sludge (SS) and municipal solid waste (MSW) Carbon dioxide sequestration capability of proposed technologies La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
Azure Chemistry approach
Azure chemistry proposes to restore or
reconstruct the ecosystems by
sustainable solutions in terms of energy,
materials, and emissions
Connection of three dimensions of
sustainability (economic,
environmental, and social) to the
remediation technologies development
Remediation is generally based on the
use of natural resources (raw materials)
and the available de-pollution
technologies, with the aim to obtain a
safe environment
Zanoletti, A., Bilo, F., Depero, L.E., Zappa, D., Bontempi, E. The first sustainable material designed for air particulate matter capture:
An introduction to Azure Chemistry (2018) Journal of Environmental Management
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
RENDERING: «Recupero ENergetico dei fanghi di DEpurazione e loro
Riutilizzo, IN alternativa ad alcune risorse naturali, per la produzione di
compositi ‘Green’»
FLY ASH
2018-2021
RENDERING
project
Financed by Ministero dell’Ambiente e
della Tutela del Territorio e del Mare
BOTTOM ASH
Reuse of fly ash from co-incineration of
Stakeholder
Sewage Sludge (SS) and Municipal Solid
Waste (MSW)
Stabilization of Municipal Solid Waste
Incineration (MSWI) fly ash
Reuse of stabilized material as filler in new
eco-composites
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
Cosmos-Cosmos Rice projects
2010-2012 2013-2015
Methods devoted to stabilization of
MSWI fly ash derived from only
municipal solid waste incineration
Amorphous silica as metals stabilizer:
Colloidal Silica Silica from rice ash
COlloidal Silica COlloidal Silica Medium
Medium to Obtain to Obtain Safe inert
Safe inert with rice ash
Reuse of stabilized material as filler in new sustainable composites
COSMOS filler
Composites
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
RENDERING vs COSMOS
RENDERING
Rendering: evolution of
Cosmos projects; Fly ash from co-
BA or SSA are substitutes of combustion
silica fume tested as metals
stabilizer FGD
COSMOS
CFA
MSWI - FA
FGD Bottom ash (BA)
CFA
Sewage sludge ash (SSA)
Silica fume
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
Stabilization method
Simple and sustainable technology
Integrated on already existing plants of waste management
CFA
BA
FGD Stabilizer
FA SSA
NO Low T
commercial treatment
chemical
reagents
(A) 120°C for 4h
(to accelerate reactions)
(B) Room temperature Leaching test
(1-2 months) [CEN EN 12457-2, 2004]
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
Stabilization of fly ash from co-combustion
Raw materials FA: CFA:
CaClOH SiO2
NaCl Al4.75Si1.26O9.63
KCl
CaCO3 FGD:
Ca(OH)2 Ca(OH)2
BA: CaSO3*0.5H2O
SiO2 CaSO4*2H2O
CaCO3
XRD analysis
Ca6Al2(SO4)3(OH)12*26H2O
(K,Fe)0.97Si1.03O4
Al2(Ca,Mg)3O12Si3
Curing materials
Stabilized samples A and B
Calcite (1 M and 2 M):
CaCO3
NaCl
SiO2
CaSO3*0.5H2O
CaSO4
Calcium silicate hydrate (C-S-H)
Calcium silicate hydrate (or C-S-H)
Is the main product of the hydration of
A: curing samples at 120 °C Portland cement.
B: curing samples at room temperature It can be obtained from the reaction of
M: months CaO and SiO2.
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
Results
Pulses
106 MSWI fly ash
Stabilized material
Chemical analysis on 105
liquid (leaching tests) Pb
Mo
104 Cl K Mn
S Ar Ca Ti Cr Fe Ni Cu Zn Ga Pb Br Rb Sr
103
102
4 6 8 10 12 14
- keV -
A: curing samples at 120 °C
B: curing samples at room temperature
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
Results
SEM analysis on powder TEM analysis on powder
The sample morphology appears to
include some fibrils, which may be due to
a C-S-H with a Ca/Si ratio lower than 1.5.
Identified
EDX maps
elements: Si Zn
C, O, Na, Mg, Al,
Si, P, S, Cl, K,
Ca, Ti, Fe and
Zn.
Ca Pb
In collaboration with:
Identified elements:
Assi, A., Bilo, F., Zanoletti, A., Ponti, J., Valsesia, A., La Spina, R., Zacco, A., Bontempi, E.
Zero-waste approach in municipal solid waste incineration: Reuse of bottom ash to stabilize fly Si, Ca, Pb and Zn.
ash (2019) Journal of Cleaner Production
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Heavy metals stabilization effect Reduction of Pb and Zn all stabilized samples have lower concentrations of Pb and Zn in their leaching solutions in respect to the starting MSWI-FA Reduction of pH pH results always lower one (and two) months after stabilization. Literature attributes this stabilization effect, due to the pH reduction, to carbonation reactions La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020
Carbonation reactions
Mineral sequestration is considered one of the promising method of CO2
emission reduction. Generally CO2 is injected into geological formations with
alkaline minerals it forms stable carbonates and is stored.
The disadvantages are related to CO2 recovery and injection (energy
requirements). Direct gas–solid carbonation has slow reaction and Direct
aqueous carbonation is expensive for large scale applications [Global NEST
Journal, Vol 20, No 3, pp 497-503, 2018]
The alternative is found in the use of industry-specific CO2 sequestration
methods, by using by-products of these same industrial processes
The approach concerning fly ashes:
• the carbonation reactions are by-products of a stabilization procedure;
• all the materials used in the process are wastes and by-products;
• the reactions don’t require control of temperature or pressure conditions;
• the process is realized in the frame of “Azure chemistry” approach. Its
sustainability is guarantee by the approach fundamentals.
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020CO2 sequestration by the proposed
technologies
• Carbonation reactions occur by mixing:
MSWI FA, Coal Fly Ash (CFA), Flue Gas
Desulphurization (FGD) residues and silica
fume (or bottom ash)
MSWI FA CFA FGD Silica fume MSWI-BA
Samples % MSWI-FA % FGD
(g) (g) (g) (g) (g)
A 130 30 40 20 \ 59.1 18.2
B 130 30 \ \ 20 72.2 \
C 130 30 40 \ 20 59.1 18.2
D 130 30 40 \ \ 65 20
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020CO2 sequestration by the proposed
technologies
Raw materials
• MSWI-FA: CaClOH
XRD analysis
• FGD: Ca(OH)2
Reactive species for
CO2 sequestration
Carbonation reaction for CaClOH:
2CaOHCl + CO2 CaCO3 + CaCl2 + H2O (1)
Carbonation reaction for Ca(OH)2 :
Ca(OH)2 + CO2 CaCO3 + H2O (2)
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Rietveld Refinement
The XRD spectrum depends on:
- phases: crystal structure, microstructure, Minimize differences between
quantity, cell volume, texture, stress, calculated and observed pattern by
chemistry etc. least-squares method
- instrument geometry characteristics:
- sample: position, shape and dimensions,
orientation.
Each of the quantity can be written in term of
parameters that can be refined (optimized).
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Rietveld refinement of different stabilized
materials
Calcite
•Rietveld method allows
the quantification of the
amorphous content (Al2O3
as the internal standard)
•The change in the
amorphous amount must
be checked to obtain
reliable information about
phases evolution
XRD pattern and corresponding Rietveld refined profile made in
stabilized sample A, one month after the synthesis. Difference curve is
also plotted.
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Results
XRD analysis
• CaClOH and Ca(OH)2
• Calcite and Vaterite were
identified in the carbonated
sample
Rietveld refinement
• 6-10% of calcite due to the natural
carbonation of MSWI-FA
• > 65 % amorphous amount
• Reduction of amorphous during
reaction with CO2
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Results
• Increase of Calcite and Vaterite when
the amorphous phase decreases
• Increase of CaCO3:
59% samples A and D
42% sample C
31% sample B
• Sample B (highest amount of MSWI-FA,
not FGD) shows the largest amount of
Vaterite and lowest amount of Calcite
• Sample D (highest amount of FGD)
shows the highest amount of Calcite and
the lowest amount of amorphous
•Vaterite formation is related to MSWI-
FA carbonation
•Carbonation of FGD favors the Calcite
formation
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Carbonation: in summary
• The carbonation reactions are by-products of a
stabilization procedure
• The changes during the ageing of the Calcite and Vaterite content
allows to highlight the carbonation process
• The carbonation of FGD residues favors the formation of Calcite,
while the Vaterite formation may be due to MSWI-FA carbonation
• These proposed recycled materials can sequestrate till to 90
gCO2/Kg of ash
• Despite carbonation of MSWI-FA was already proposed as possible
CO2 sequestration technology, the potential maximum theoretical
CO2 sequestration quantity is reported to be about 58 gCO2/kg of FA
in literature.
Assi, A., Federici, S., Bilo, F., Zacco, A., Depero, L.E., Bontempi, E.
Increased sustainability of carbon dioxide mineral sequestration by a technology involving fly ash stabilization (2019) Materials
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Global avoided CO2 emissions due to the
stabilization of co-combusted fly ash
Waste treatment in the place where it is produced;
Reuse of FA and BA;
CO2 sequestration due to carbonation reaction
Parametri Kg CO2-eq/t FA
Trasporto MSWI FA (600 Km) 36.24
Processo solidificazione MSWI FA 285.6
Reazione carbonatazione 55
Smaltimento discarica MSWI BA 0.8
Macinazione MSWI BA -1.32
Emissioni evitate 376.32
EMISSIONS AVOIDED 376.32 kg CO2-eq/t FA
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Future activities
• Make a chamber with controlled environmental
conditions (temperature, humidity, etc)
• Substitute FGD residues (derived from coal
combustion) with other wastes and by-products
• Use of accelerated carbonation to sequestrate more
carbon dioxide
• Evaluate the eventual formed amorphous calcium
carbonate: the amount of CO2 sequestrated by this
technology is expected to be higher than that
evaluated only considering the formed crystalline
calcium carbonate
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020Published papers:
- Benassi, L., Zanoletti, A., Depero, L.E., Bontempi, E.
Sewage sludge ash recovery as valuable raw material for chemical stabilization of
leachable heavy metals (2019) Journal of Environmental Management
- Assi, A., Federici, S., Bilo, F., Zacco, A., Depero, L.E., Bontempi, E.
Increased sustainability of carbon dioxide mineral sequestration by a technology
involving fly ash stabilization (2019) Materials
- Assi, A., Bilo, F., Zanoletti, A., Ponti, J., Valsesia, A., La Spina, R., Zacco, A.,
Bontempi, E.
Zero-waste approach in municipal solid waste incineration: Reuse of bottom ash to
stabilize fly ash (2019) Journal of Cleaner Production
- Zanoletti, A., Bilo, F., Depero, L.E., Zappa, D., Bontempi, E.
The first sustainable material designed for air particulate matter capture: An
introduction to Azure Chemistry (2018) Journal of Environmental Management
- Pasquali, M., Zanoletti, A., Benassi, L., Federici, S., Depero, L.E., Bontempi, E.
Stabilized biomass ash as a sustainable substitute for commercial P-fertilizers
(2018) Land Degradation and Development
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus - 4-5 febbraio 2020THANK YOU FOR YOUR
ATTENTION
Acknowledgements:
Ministero dell’Ambiente e della
Tutela del Territorio e del Mare
e-mail:elza.bontempi@unibs.it
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