H 2 S adsorption from biogas with thermal treatment residues - - PowerPoint PPT Presentation

H2S adsorption from biogas with thermal treatment residues

Valentine Gasquet1, Boram Kim1, Léa Sigot2 & Hassen Benbelkacem1

1 DEEP- INSA Lyon 2 LRGP, CNRS, Université de Lorraine,

7th International Conference on Sustainable Solid Waste Management Friday June 28th 2019

BIOGAS, WHAT IS IT?

Source : Department of Environmental & Conservation

A renewable, local and uninterrupted energy

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CH4 CO2

Air Pollutants CH4

CO2

Air Pollutants

BIOGAS, WHAT IS IT?

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• Water
• H2S
• Siloxanes
• Etc

H2S

H2S ISSUE Flammable Dangerous for the environnent Toxic

Between 100 and 10 000 ppm

H2S

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BIOGAS PURIFICATION For all biogas types: H2S issue Current solutions :

• Adsorption on activated carbon or ferric
• xide
• Scrubbing tower
• Biofilters

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EXAMPLE

Raw biogas Cleaned biogas 600 Nm3/h [H2S]=1000 ppm Removal capacity : 50 % 75 k€/yr Impregnated activated carbon

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Alternative adsorbant

?? € /yr

• Municipal solid waste incineration

bottom ash

• Biomass ash
• Biochars
• Pyrolyzed sewage sludge
• Industrial waste

ALTERNATIVE ADSORBANTS

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Number of articles concerning H2S adsorption with alternative materials

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 1 2 3 4 5 6 7 8 9 10 Year Number of articles

 Thermal treatment residues

ALTERNATIVE ADSORBANTS

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Biogas type:

Real or synthetic, composition

Process parameters:

Reactor size, experiment length, flow

Difficult to compare

Objectives :  Compare adsorbents performances for H2S removal in the same experimental conditions  Link adsorption capacity and materials characterization Objectives :  Compare adsorbents performances for H2S removal in the same experimental conditions  Link adsorption capacity and materials characterization

SELECTED MATERIALS

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Biomass ash Municipal solid waste incineration bottom ash

Source : CCI Lozère – Mission bois-énergie Source : Annual Report Household Waste Service - – Grand Angoulême

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Biochar

Incinerated sewage sludge

Source : Green Charcoal Internationam Source : Leaflet Pyrofluid - VEOLIA

SELECTED MATERIALS

EXPERIMENTAL SET-UP

 Raw biogas  Reactor volume = 250 cm3  Flow : 1L/min  Length ≈ 2 weeks  Residence time = 14 s

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EXPERIMENTAL SET-UP

Adsorption reactors Humidification vial Flowmeter

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Systematical characterisation of materials Physical characterisation Porosity Water content Chemical characterisation Elementary composition pH MATERIAL CHARACTERISATION

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For raw and used materials :

ELEMENTARY COMPOSITION

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SiO2 Al2O3 Fe2O3 CaO P2O5 Other minera ls Loss-

• n-

ignitio n

BA

SiO2 Al2O3 Fe2O3 CaO P2O5 Other minera ls Loss-

• n-

ignitio n

ISS

SiO2 Al2O3 Fe2O3 CaO

P2O5 Other minerals

Loss-

• n-

ignitio n

MSWI BA

SiO2; 0,3; 0,32% Al2O3; 0,1; 0,06% Fe2O3; 0,0; 0,03% CaO P2O5; 0,1; 0,12% Other minerals

Loss-

• n-

ignitio n

BCH

ELEMENTARY COMPOSITION

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SiO2 Al2O3 Fe2O3 CaO P2O5 Other minera ls Loss-

• n-

ignitio n

BA

SiO2 Al2O3 Fe2O3 CaO P2O5 Other minera ls Loss-

• n-

ignitio n

ISS

SiO2 Al2O3 Fe2O3 CaO

P2O5 Other minerals

Loss-

• n-

ignitio n

MSWI BA

SiO2; 0,3; 0,32% Al2O3; 0,1; 0,06% Fe2O3; 0,0; 0,03% CaO P2O5; 0,1; 0,12% Other minerals

Loss-

• n-

ignitio n

BCH

BA MSWI BA BCH ISS 2 4 6 8 10 12 14 0% 10% 20% 30% 40%

pH AND WATER CONTENT

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p H Water content (%)

Surface area (m²/g) Mesopore volume (cm3/g) Micropore volume (cm3/g) Bulk specific gravity Biomass ash 32 MSWI bottom ash 17 Biochar 919 Incinerated sewage sludge 3 Surface area (m²/g) Mesopore volume (cm3/g) Micropore volume (cm3/g) Bulk specific gravity Biomass ash 32 0.090 0.026 MSWI bottom ash 17

• Biochar

919 0.196 0.315 Incinerated sewage sludge 3 0.021 0.000 Surface area (m²/g) Mesopore volume (cm3/g) Micropore volume (cm3/g) Bulk specific gravity Biomass ash 32 0.090 0.026 0.7 MSWI bottom ash 17

• 2.3

Biochar 919 0.196 0.315 0.1 Incinerated sewage sludge 3 0.021 0.000 0.8

POROSITY

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ADSORPTION TESTS

1 2 3 4 5 6 7 8 9 10 10 20 30 40 50 60 70 80 90 100

Evolution of the retention rate

Biomass ash Biochar Incinerated sewage sludge MSWI bottom ash Time (days) Retention rate (%)

ALCALINITY

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BA MSWI BA BCH ISS 2 4 6 8 10 12 14

pH variation before and after adsorption

Raw material Used material

Surface area (m²/g) Mesopore volume (cm3/g) Micropore volume (cm3/g) Raw material Used material Raw material Used material Raw material Used material Biomass ash 32 9 MSWI bottom ash 17 9 Biochar 919 66 Incinerated sewage sludge 3 2 Surface area (m²/g) Mesopore volume (cm3/g) Micropore volume (cm3/g) Raw material Used material Raw material Used material Raw material Used material Biomass ash 32 9 0.090 0.045 0.026 0.000 MSWI bottom ash 17 9

• Biochar

919 66 0.196 0.095 0.315 0.007 Incinerated sewage sludge 3 2 0.021 0.021 0.000 0.000

POROSITY

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= =

Micropores filling

CONCLUSION

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Raw biogas Clean biogas

Biomass ash Biochar MSWI bottom ash Incinerated sewage sludge Basic materials, humid and containing mineral oxides and some porosity Porous material but no mineral oxides Contain mineral

• xides but non

porous material

ON GOING STUDY - ADSORPTION MECHANISMS

Modified from Hervy et al. (2018)

Influence

• f porosity

H2S

• xidation

Chemisorption Physisorption

OUTLOOK

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 Understand adsorption mechansims with further analysis of materials : Infra-red and Raman spectroscopy, thermogravimetric analysis …  Improve adsorbent’s capacities with formulation and granulation

Thank you for your attention