The role of biogas in greening the gas grid
Professor Jerry D Murphy Director of MaREI centreChair of Civil, Structural & Environmental EngineeringLeader International Energy Agency Bioenergy Energy from Biogas Task 37AD Network Research Colloquium, “Beyond Biogas”, Manchester January 23-25th, 2019
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RESEARCH AREA 5 BIOENERGY: RENEWABLE GAS
6 European gas grids have committed to 100% green gas in the gas grid by 2050
Green Gas
First stage of Industry
Digestion of wet organic biomass
RESEARCH AREA 5 BIOENERGY: RENEWABLE GAS
Grass to transport fuel
harvest silage storage
macerator
Source: energiewerkstatt, IEA and personal photos
anaerobic digester
weigh bridge
Biogas service station Scrubbing &storage
RESEARCH AREA 5 BIOENERGY: GAS FROM GRASS
Higher Grass Silage Input
Higher Dairy Slurry Input
R1 R2 R3 R4 + R5 & R6
Grass %VS
Slurry %VS
R6 100 0
R5 80 20
R4 60 40
R3 40 60
R2 20 80
R1 0 100
Continuous digestion of grass and slurry
RESEARCH AREA 5 BIOENERGY: GAS FROM GRASS
0
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L C
H4
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-1V
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REACTOR NO.
OLR = 2.0 kg VS m-3 d-1
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OLR = 2.5 kg VS m-3 d-1
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REACTOR NO.
OLR = 3.0 kg VS m-3 d-1
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OLR = 3.5 kg VS m-3 d-1
Increased gas production with increased grass
RESEARCH AREA 5 BIOENERGY: GAS FROM GRASS
3.5 OLR
HRT 21 days
12%
decrease
in SMY
Reduction in yield of mono-digestion at high OLR
RESEARCH AREA 5 BIOENERGY: TRACE ELEMENTS
Trace element analysisRESEARCH AREA 5 BIOENERGY: TRACE ELEMENTS
RESEARCH AREA 5 BIOENERGY: IMPROVED DIGESTION PERFORMANCE
PretreatmentAnaerobic digestion
Hydrolysate
Upgraded Biogas(Biomethane)
Feedstocks and pretreatment Enhanced anaerobic digestion Solid digestate pyrolysis
Feedstocks
microbes Solid digestate
Liquid digestate(Soil amendment) Pyrolysis
Syngas, Bio-oil
Pyrochar
RESEARCH AREA 5 BIOENERGY: DEMAND DRIVEN BIOGAS
Third stage of Industry
Green Gas from seaweed
RESEARCH AREA 5 BIOENERGY: SEAWEED
RESEARCH AREA 5 BIOENERGY: SEAWEED
RESEARCH AREA 5 BIOENERGY: SEAWEED
RESEARCH AREA 5 BIOENERGY: SEAWEED
Seasonal Variation in composition of Laminaria Digitata Seasonal Variation in biomethane yield from Laminaria Digitata
Seasonal Variation in A. nodosum
RESEARCH AREA 5 BIOENERGY: SEAWEED
Long term co-digestion of seaweed with dairy slurry
RESEARCH AREA 5 BIOENERGY: SEAWEED
Cultivating Seaweed
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Position adjacent to fish farms, protect fish from jelly fish
Increased yields of seaweed as compared to pristine waters
Clean water of excess nutrients
Harvest when yield is highest
RESEARCH AREA 5 BIOENERGY: SEAWEED
Higher methane yields after ensiling can compensate for silage fermentation losses.
No losses in methane yield occurred during 90 day storage for 4 of 5 species.
RESEARCH AREA 5 BIOENERGY: SEAWEED
RESEARCH AREA 5 BIOENERGY: SEAWEED
RESEARCH AREA 5 BIOENERGY: SEAWEED
Sustainability Criteria:• 70% GHG emissions reduction for transport biofuels• 80% GHG reduction for renewable heat.Advanced biofuels (such as seaweed biomethane) may not meet this. We need:• Cascading bioenergy• Carbon captureWe need bioenergy with carbon capture:• Micro-algae• Power to gas
RESEARCH AREA 5 BIOENERGY: MICROALGAE
Fourth stage of Industry
Green Gas from electricity
RESEARCH AREA 5 BIOENERGY: ELECTROFUELS
Audi E-gas at Wertle, Germany
Food waste biomethane
Production of hydrogen in 6 MW electrolysis
Production of methane via Sabatier
1000 Audi NGVs
Cascading bioenergy, circular economy, carbon capture.
Sabatier Equation: 4H2 + CO2 = CH4 + 2H2O
RESEARCH AREA 5 BIOENERGY: ELECTROFUELS
BIOENERGY
Sabatier Equation: 4H2 + CO2 = CH4 + 2H2O
RESEARCH AREA 5 BIOENERGY: ELECTROFUELS
RESEARCH AREA 5 BIOENERGY: ELECTROFUELS
RESEARCH AREA 5 BIOENERGY: ELECTROFUELS
RESEARCH AREA 5 BIOENERGY: ELECTROFUELS
RESEARCH AREA 5 BIOENERGY: ELECTROFUELS
Base case 80:20 Grass: slurry on a VS basis; 2% fugitive CH4 losses: 41% green electricitySequestration of 2.2tCO2/ha/a considered
2018: Causeway project13 additional filling stations3 additional digesters
2019: Green gas certificates
RESEARCH AREA 5: ECONOMIC IMPACTGNI CASE STUDY
2030: 20% renewable gas by 2030
2018: 1st gas to grid siteEquivalent to 600 CNG buses
2007: Future of Renewable Gas
“Unlocking the potential of our marine and renewable energy
resources through the power of research and innovation”
International Energy Agency Bioenergy: Task 37 Biogas Reports
International Energy Agency Bioenergy: Task 37 Biogas Success Stories
IEA Workshops:
Oxfordshire, Sept 2016;
Toowoomba, Nov 2016;
Sao Paulo, Jan 2017;
Vlijmen, April 2017;
Esjberg, Sept 2017,
Jyvaskyla March 2018,
Cork, Sept 2018
International Energy Agency Bioenergy: Task 37 Biogasd Workshops