BIO-CATALYTIC CONVERSION OF SYNGAS: CURRENT AND POTENTIAL APPLICATIONS FOR BIOFUEL PRODUCTION
Mathieu Haddad, Ph.D.
Department of Microbiology, Immunology and Infectious Diseases
INTRODUCTION: WASTE TODAY
• 2012: 3 billion urbanites 1.2 kg MSW / person / day (1.3 billion tonnes per year)
• 2025: 4.3 billion urbanites 1.42 kg MSW / person / day (2.2 billion tonnes per year)
• Public Health and environmental concerns
• Actual (downstream) solid waste management:
• Recycling
• Anaerobic digestion / Composting
• Incineration
• Landfill disposal
Hoornweg, D., Bhada-Tata, P., & Kennedy, C. (2013). Environment: Waste production must peak this century. Nature, 502(7473), 615–617
INTRODUCTION: GASIFICATION AND SYNGAS
An emerging waste to energy technology: Gasification
Inc.:AlterNRG, Dynamis Energy, Enerkem, InEnTec, Plasco Energy Group...
“Conversion at high temperature (800 – 1800°C) at atmospheric or elevated pressures (up to 33 bar) with limited O2 of any carbonaceous fuel to a gaseous product with a useable heating value: syngas (CO, H2, CO2)”
Higman, C. Van der Burgt, M., 2003. Gasification. Gulf Professional Publishing Higman, C. (2013). Gasification Technologies Conference. In State of the Gasification Industry – the Updated Worldwide Gasification Database. Colorado Springs (CO).
Cumulative Worldwide Gasification Capacity and Growth
I – CONVENTIONAL GAS TO LIQUID: FISCHER-TROPSCH
The FT process uses metal catalysts (Fe/Co) to thermochemically convert syngas into liquid hydrocarbons:
n CO + 2n H2 CnH2n + n H2O
http://www.altonaenergy.com/project_gasification.php
I – CONVENTIONAL GAS TO LIQUID: FISCHER-TROPSCH
Daniell J, Köpke M, Simpson SD. Commercial Biomass Syngas Fermentation. Energies. 2012; 5(12):5372-5417.
Griffin, D. W., & Schultz, M. A. (2012). Fuel and chemical products from biomass syngas: A comparison of gas fermentation to thermochemical conversion routes. Environmental Progress & Sustainable Energy, 31(2), 219–224.
Pros:
• Fast process / Low gas retention time
• Known technology
Cons:
• Energy intensive process (7 MPa & 350°C)
• High intolerance to contaminants (H2S, CO2, HCN, HCl): extensive syngas cleaning required
• High CAPEX
• Catalysts require a fixed ratio of gases: low flexibility
• Low catalyst selectivity (45%): undesired products
Energy efficiency
• Feedstock: Woody biomass
• Final product: ethanol
• Energy efficiency: 45%
II - INNOVATIVE GTL PROCESS: SYNGAS FERMENTATION
Innovative approach: Acetogens as biocatalysts to convert syngas into liquid hydrocarbons.
Müller, Volker, and Frerichs, Janin(Sep 2013) Acetogenic Bacteria. In: eLS. John Wiley & Sons Ltd, Chichester
Daniell J, Köpke M, Simpson SD. Commercial Biomass Syngas Fermentation. Energies. 2012; 5(12):5372-5417
CO /
CO2 + H2
Acetate
M. thermoacetica
A. woodi
C. aceticum
Ethanol
C. autoethanogenum C. ljungdahlii
C. ragsdalei C. carboxydovorans
Butanol
C. carboxidovorans C. drakei
C. scatologenes B. methylotrophicum
2,3 Butanediol
C. autoethanogenum C. ljungdahlii C. ragsdalei
Definition: Anaerobic prokaryotes characterized by the Wood–Ljungdahl pathway of CO2 reduction with the acetyl-CoA synthase as the key enzyme of the pathway.
II - INNOVATIVE GTL PROCESS: SYNGAS FERMENTATION
Müller, Volker, and Frerichs, Janin(Sep 2013) Acetogenic Bacteria. In: eLS. John Wiley & Sons Ltd, Chichester
Daniell J, Köpke M, Simpson SD. Commercial Biomass Syngas Fermentation. Energies. 2012; 5(12):5372-5417
Griffin, D. W., & Schultz, M. A. (2012). Fuel and chemical products from biomass syngas: A comparison of gas fermentation to thermochemical conversion routes. Environmental Progress & Sustainable Energy, 31(2), 219–224.
Pros:
• Mesophilic conditions (30-40°C), 1 atm
• Tolerance to impurities: fewer gas cleanup required
• High selectivity regardless of syngas composition: products at predetermined ratios
• Low CAPEX / OPEX
Cons:
• Limited mass transfer rate of gases: lower solubility (especially CO and H2)
• Low cell density => low volumetric activity
Energy efficiency
• Feedstock: Woody biomass
• Final product: ethanol
• Energy efficiency: 57%
II - INNOVATIVE GTL PROCESS: SYNGAS FERMENTATION
http://www.ineos.com/en/businesses/INEOS-Bio/
Daniell J, Köpke M, Simpson SD. Commercial Biomass Syngas Fermentation. Energies. 2012; 5(12):5372-5417
INEOS Bio (Vero Beach, FL)
Start date: November 1st, 2012
Scale: Commercial plant
Feedstock: yard, vegetative and household waste
Biocatalyst: GM Closrtidium ljungdahlii
Products:
• 6 MW (gross) of electricity (unused syngas & recovered heat)
• 8 million gallons of ethanol per year
Capacity: 300 dry tons per day
II - INNOVATIVE GTL PROCESS: SYNGAS FERMENTATION
http://www.coskata.com/
Daniell J, Köpke M, Simpson SD. Commercial Biomass Syngas Fermentation. Energies. 2012; 5(12):5372-5417
Coskata (Madison, PA)
Start date: October, 2009
Scale: Demonstration plant
Feedstock: wood biomass and municipal solid waste
Biocatalyst: GM Clostridium ragsdalei & Clostridium carboxidivorans
Products: Ethanol
Capacity: ND
II - INNOVATIVE GTL PROCESS: SYNGAS FERMENTATION
http://www.lanzatech.com/
http://www.biofuelsdigest.com/bdigest/2013/08/14/algae-to-fuel-developers-lanzatech-is-supersizing-our-fries/
Daniell J, Köpke M, Simpson SD. Commercial Biomass Syngas Fermentation. Energies. 2012; 5(12):5372-5417
Lanzatech (New Zealand, USA, India, China)
Start date: October, 2005
Scale: Pilot plant (NZ), Demonstration plant (China),
Feedstock: steel mill off-gases, syngas from wood residues
Biocatalyst: GM Clostridium autoethanogenum
Products: Ethanol, Butanol & and 2,3-Butanediol
Capacity: ND
III – CONVENTIONAL GTG: THE WATER GAS SHIFT REACTION
CO + H2O(g) = H2 + CO2 ΔG0=-20kJ/mol
Newsome, D.S., 1980. The Water-Gas Shift Reaction. Catalysis Reviews, 21(2), pp.275–318
Torres, W., Pansare, S.S. & Goodwin, J.G., 2007. Hot Gas Removal of Tars, Ammonia, and Hydrogen Sulfide from Biomass Gasification Gas. Catalysis Reviews, 49(4), pp.407–456
Conventional method: catalysts
Two-step process: Cr2O3 – Fe2O3 (≈350°C) and CuO (≈200°C)
Pros:
• Fast process / Low gas retention time
• Known technology
Cons:
• Catalysts need to be regenerated (energy intensive & costly)
• High intolerance to sulfur: need for gas pretreatment (H2S <0.1 ppm)
• High CAPEX
• Catalysts are effective under specific conditions: low flexibility
CO + H2O(g) = H2 + CO2 ΔG0=-20kJ/mol
Svetlichny, V.A., Sokolova, T.G., Gerhardt, M., Ringpfeil, M. (1991). Carboxydothermus hydrogenoformans gen. nov., sp. Nov., a CO-utilizing thermophilic anaerobic bacterium from hydrothermal environments of Kunashir Island. System. Appl. Microbiol. 14, 254-260.
Svetlichny, V.A., Peschel, C., Acker, G., Meyer, O., (2001) Two Membrane‐Associated NiFeS‐ Carbon Monoxide Dehydrogenases from the Anaerobic Carbon‐Monoxide‐Utilizing Eubacterium Carboxydother
mus hydrogenoformans. Journal of Bacteriology. 183(17), 5134– 5144.
Innovative approach: a biological catalyst, Carboxydothermus hydrogenoformans
Pros:
• Hyperthermophilic (70°C) with High duplication time (≈2 hours)
• CO (or pyruvate) as sole source of Carbon & Energy
• High tolerance to sulfur
• High H2 yield (≥95%)
• 5 CODH: Tolerant to 100% CO / 2 bars in the headspace
Cons:
• Low biomass density (planktonic cultures) -> low volumetric activity
• CO mass transfer limitation: Low solubility at 70°C
III – INNOVATIVE GTG: THE BIO-WATER GAS SHIFT REACTION
Set Up
• 35 L gas-lift reactor, @70°C
• 100% CO & Basal Mineral Medium
Operation
• 3 months
• 2 Phases: unsupported vs. supported (1.0 g.L-1 bacto-peptone) growth
• Gradually augmenting CO loading
Haddad, M., Cimpoia, R., & Guiot, S. R. (2014). Performance of Carboxydothermus hydrogenoformans in a gas-lift reactor for syngas upgrading into hydrogen. International Journal of Hydrogen Energy, 39(6), 2543–2548
Material & Methods
III – INNOVATIVE GTG: THE BIO-WATER GAS SHIFT REACTION
• Logarithmic relationship between QR:QCO and CO Conversion Efficiency and Specific Activity
• mass transfer limited < QR:QCO=40 < biologically limited
Performance of the gas-lift reactor under
supported growth of C. hydrogenoformans
Unsupported Growth
YH2 constant ≈ 80%
ECO max (79%) obtained at QCO = 0.05 mol.Lrxr
-1.d-1
QCO max = 0.08 mol.Lrxr-1.d-1
If QCO= 0.13 mol.Lrxr-1.d-1
activity drop
and reactor failure (biologically limited)
Supported Growth (peptone)
YH2 constant ≈ 95%
ECO max (90%) obtained at QCO = 0.05 mol.Lrxr
-1.d-1
QCO max = 0.30 mol.Lrxr-1.d-1
If QCO= 0.46 mol.Lrxr-1.d-1
activity drop
and reactor failure (biologically limited)
Results & Discussion
Haddad, M., Cimpoia, R., & Guiot, S. R. (2014). Performance of Carboxydothermus hydrogenoformans in a gas-lift reactor for syngas upgrading into hydrogen. International Journal of Hydrogen Energy, 39(6), 2543–2548
III – INNOVATIVE GTG: THE BIO-WATER GAS SHIFT REACTION
Haddad, M., Cimpoia, R., & Guiot, S. R. (2014). Performance of Carboxydothermus hydrogenoformans in a gas-lift reactor for syngas upgrading into hydrogen. International Journal of Hydrogen Energy, 39(6), 2543–2548
III – INNOVATIVE GTG: THE BIO-WATER GAS SHIFT REACTION
Conclusion
• Promising technology: high and stable performances (YH2, ECO, A)
• Importance of 2 parameters: bacto-peptone and QR:QCO ratio
• With biomass concentration of 0.106 gVSS.Lrxr-1 and bioactivity of 2.7 molCO.gVSS
-1.d-1 maximal volumetric CO conversion ca. 0.28 molCO.Lrxr
-1.d-1 (8m3.mrxr-3.d-1)
• Low cell density affected the volumetric activity (18x lower than sessile growth)
limitation for higher QCO
Enhanced for possible scale-up
• Sessile growth using physical medium (beads) will allow 18x higher cellular density =>Enhanced volumetric activity => Higher QCO
• Liquid phase renewal and recirculation: maximize cellular activity and enhance mass transfer
SUMMARY – SYNGAS FERMENTATION – GAS TO LIQUID
Second generation biofuel technology currently in development with many advantages (compared to chemical catalysis):
• low-temperature/pressure
• tolerance to several impurities
• flexible H2/CO ratio feed gas
• higher overall fuel and thermal efficiency
Actual technologies: acetogenic bacteria for the production of acetate, ethanol, butanol & 2,3-butanediol.
Improvement for higher yields / rates made possible using:
• Metabolic engineering
• Reactor design
• Process optimization
SUMMARY – SYNGAS FERMENTATION – GAS TO GAS
Next-generation syngas fermentation:
• gaseous biofuel (H2, CH4)
• Mixed population: acetogenic and hydrogenogenic bacteria
• Metabolically engineered hydrogenogenic carboxydotrophs with higher yields / hydrogen production rates
QUESTIONS?
ACKNOWLEDGMENT
Doctoral Supervisor: Serge R. Guiot, Ph.D.
Bioengineering Group, NRC-CRNC Montreal