biological syngas methanation - gas as part of the green

CELL & ENZYME TECHNOLOGY JO PHILIPS

3 DECEMBER 2018 ASSISTANT PROFESSORDEPARTMENT OF ENGINEERING

AARHUSUNIVERSITY

BIOLOGICAL SYNGAS METHANATION

Nabin Aryal Post-doctoral Researcher Aarhus University, DenmarkJune 23th 2020



AARHUSUNIVERSITY

WP1 GAS CONDITIONING• Analyze existing and emerging technologies for biogas upgrading and syngas methanation.

• Focus is on development and characterization of gas supply and emerging gas technologies.

• New and unconventional sources such as syngas are investigated, especially in relation to how these can best be conditioned for the existing gas infrastructure, addressing challenges as cost efficient methanation and upgrading to natural gas quality.



AARHUSUNIVERSITY

FUTUREGAS (WP1)-TASK

Developing biogas plants emission free and sustainable

Task• Technological assessment on biogas upgrading (Biological)• Methane emission from biogas upgrading plants (1.97%) • Syngas production from gasification (Wood/ Straw)• Syngas methantion and upgrading (Trickle bed reactor set-up)



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MICROBIAL BIOMETHANTION• Biological methanation is an attractive alternative for biogas upgrading • Eco-friendly, and low energy demanding • Hydrogen Injection for biogas upgrading (In situ /Ex situ upgrading)• Bioelectrochemical biomethanation approaches utilize CO2 and electricity for methane production (BES)

Development of technologies to inject H2 in full-scale

Biomethane

Bioelectrochemical System



AARHUSUNIVERSITY

BIOLOGICAL SYNGAS METHANATION

Fig: Coupling of gasification, syngas fermentation for biological syngas biomethanation

• Syngas methanaion is attractive altrnative to produce biomethane• Syngas could be produced utilzing waste biomass in the gasifier



AARHUSUNIVERSITY

GASIFICATION• 1.5 kw Laboratory scale allothermal gasifier was used at

different 750 oC, 800 oC, 850 oC, and 900 oC allothermaltemperature

• Commercially available pellet was used with 8 mm diameter

• The olivine (Mg²⁺, Fe²⁺)₂SiO₄ catalysis was used as a bed material for supporting and enhancement of gasification

1.5 kw Laboratory scale allothermal gasifier (DGC)

Pellet Olivine



AARHUSUNIVERSITY

SYNGAS COMPOSITION The syngas composition (750oC)

• Carbon monoxide 9.38%

• Hydrogen 15.42%

• Carbon dioxide 66.96%

• Methane 4.34%

• Other hydrocarbons

CO % concentration and H2 % concentration is low

Insufficient Stoichiometry (CO2:H2=40:60) for biomethanation

Fig:-Wood pellet gasification and composition of syngas with different allothermal operating temperature condition A) 750 oC, B) 800 oCC) 850 oC, & D) 900 oC

Ref: Rasmussen & Aryal, Fuel 2020



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LABORATORY EXPERIMENT

Gylling J. 2018 ( Master thesis )

CH4 37.78%

Not meeting the gridrequirement



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SYNGAS UPGRADING

Details Syngas Syngas upgrading

CO (mmol/l/h) -0.05±0.02 -0.06±0.02

H2 (mmol/l/h) -0.45±0.34 ad

CH4 (mmol/l/h) 0.05±0.01 0.30±0.02

CO2 (mmol/l/h) 0.02±0.002 -0.24±0.1

CH4 (%) 37.78±3 95±1

CH4 (mmol/lbed/h) na 1±0.06

CH4 (mmol/m3/h)$ na 300±19

Table 1: Syngas biomethanation

Exogenous Hydrogen addition for syngas biomethanation



AARHUSUNIVERSITY

CONCLUSION

• Syngas is a key energy carrier and intermediate product and can be derived from the gasification of waste biomass.

• Syngas upgrading is possible in the same reactor via exogenous hydrogen addition

• Syngas upgrading in trickle bed reactor produces biomethane that contains 95±1% CH4

• The cost of gasification, syngas methanation and syngas upgrading (Hydrogen) are essential steps for economic feasibility calculation



AARHUSUNIVERSITY

THANK YOU

biological syngas methanation - gas as part of the green

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