H - Georg

Reducing H2S Emissions from Geothermal
Power Plants. Collaboration of Icelandic
Energy Companies
From Waste to Value, GEORGE seminar 3. April 2013
Bjarni Már Júlíusson
Project Manager H2S
Outline
• H2S project background
• Gas emissions from Icelandic geothermal power plants
• Measuring of H2S and regulations
• The SulFix project
• Summary
Geothermal Gases
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Emissions of non condensable gases are an inevitable part of high temperature geothermal utilization
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Major gases in geothermal fluids
CO2, H2S, H2, N2, CH4, Ar
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Some of the gases are environmentally important
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Concentration depends on:
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Greenhouse gases
Corrosive
Toxic
Flammable
Smell bad
Temperature
Composition of fluid
Geological setting
New regulation (514/2010) about H2S concentration levels demands that the geothermal industry takes action to reduce emissions
H2S Project Management Structure
OR Steering Group
Collaboration Steering Group
OR: Bjarni Bjarnason Chairman
LV: Óli Grétar Sveinsson
HS: Þór Gíslason
Bjarni Bjarnason Chairman
Páll Erland, Virkjunum og sölu
Hildigunnur Thorsteinsson, Þróun
Hólmfríður Sigurðardóttir, umhverfisstj.
Eiríkur Hjálmarsson, upplýsingafltr.
OR Advisory Committee
Collaboration Advisory
Committee
OR: Ingvi Gunnarsson
LV: Sigurður H Markússon
HS: Kristín Vala Matthíasdóttir Project manager
Project manager
Bjarni Már Júlíusson
Bjarni Már Júlíusson
ESA
Tracer ferilp. ESA
CarbFix
ISOR, VER, HÍ, Vista, Mannvit, Vatnaskil, Kemía, Veðurvaktin
Foreign bodis: Trimeric Corporation, IGA
Útfellingartilr. IG
Advisory bodies
Gasskiljustöð BMJ
SulFix 2. áf. BMJ
Útbl.háfur LV/SHM
H2S í lút HS/KVM
H2S Collaboration
BMJ
Dr. Edda Sif Arnardóttir, CarbFix, reservoir engin.
Dr. Einar Gunnlaugsson, chemistry, geology
Guðmundur Kjartansson, well field
Guðmundur Hagalín, Head of Power Plant
Operation
Helgi Leifsson, development
Ingólfur Hrólfsson, prior work and solutions
Ingvi Gunnarsson, geochemist
Gas Emissions from Hellisheiði and Nesjavellir Power Plants
Nesjavellir
power plant
Hellisheiði and Nesjavellir power plants • Located on the Hengill central volcano 20‐25 km from Reykjavík
• Nesjavellir commissioned in 1990 and Hellisheiði in 2006
• Installed capacity and annually emission of H2S Hellisheiði
‐ 303 MWe
‐ 133 MWth
‐ 16,000 tons H2S
Hellisheiði Power plant
Nesjavellir
‐ 120 Mwe
‐ 290 MWth
‐ 9,400 tons H2S
• Reservoir temperature between 250‐320°C.
• Concentrated in the steam phase during separation of the geothermal fluid.
• Concentration of gases in the steam phase is around 0,4% • From condensers they are pumped to atmosphere using vacuum pumps
• Released to atmosphere on top of cooling towers to secure better distribution
Composition of Gas and Total Emissions
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Gas emissions have been gradually increasing Total emissions from both power plants were 62000 tons CO2 and 28000 tons H2S in 2012
Equals about 5‐6% of CO2 emissions from fossil fuel power plants of comparable size.
Current CO2 and H2S Emissions from Icelandic Geothermal Power Plants
Power company
Installed CO2
Power MWe tons/year
H2S
tons/year
Total
tons/year
HS Orka
175
78.930
1.880
80.816
Landsvirkjun
63
40.975
6.783
47.758
Orkuveita
Reykjavíkur
423
57.474
26.474
83.949
Total
661
177.379
35.137
212.523
Planned Projects ‐Estimated Increase in CO2 and H2S Emissions
Power company
Installed CO2
Power MWe tons/year
H2S
tons/year
Total
tons/year
HS Orka
130
13.000
1.010
14.010
Landsvirkjun
135
22.670
9.845
32.515
Orkuveita
Reykjavíkur
90
19.158
5.370
24.528
Total
355
54.828
16.225
71.053
Concentration of H2S in Atmosphere
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Icelandic regulation from 2010 on atmospheric concentration of H2S − Stricter rules take effect in 2014
− Stricter than WHO guidelines
− Requires the geothermal industry in Iceland to reduce H2S emissions
− The Icelandic energy companies have requested that the effective date is delayed until 2020.
Comparison of H2S Limits in Scale
H2S µg/m3
15.000 µg/m3 eyes irritation 6
7.000 µg/m3 HES (VER) 8h limit on site work
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150 µg/m3uWHO
24h. average
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50 µg/m3
24h. average
3
5 µg/m3
Yearly average
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1
0
0
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SulFix Project ‐ Returning the H2S back to Where it Came From
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Gases flash from the geothermal fluid in the production wells
H2S from the power plant will be dissolved in condensate water Dissolved gases are injected back into the high temperature geothermal reservoir
The aim is to use water‐rock reactions taking place in high temperature geothermal reservoir to mineralize the H2S (Metal Sulfides)
Why Dissolution and Reinjection of H2S?
The aim of SulFix is to develop a method to lower H2S emissions from high temperature power plants that has lower operation costs and is more environmentally friendly than current H2S cleaning methods
Returning H2S back into the geothermal system in the same form as it came out in has to be considered a good H2S abatement method
From Pilot to Industrial scale
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Next step is to build an adsorption tower to clean out 15‐30% of H2S from the power plant and inject it back into the geothermal reservoir (2014)
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If successful, an amine unit will be installed to selectively remove H2S from the geothermal gas stream and dissolve it in the effluent water. 50% removal of H2S (2016)
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An additional amine unit installed if needed to comply with Icelandic regulations on atmospheric H2S concentration.
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Parallel to this OR will continue looking at conventional H2S abatement solutions (oxidation)
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And leave open possible collaboration with companies aiming at producing valuables from the gas
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Carbon Recycling (Methanol)
Prokatín (single cell proteins) CO2 for green houses
Sulfuric acid
SulFix Project and Work Breakdown Structure
• Project Master Plan
• Work breakdown structure and milestones
Summary
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Emissions of geothermal gases are an inevitable part of high temperature geothermal utilization.
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Annually Icelandic geothermal power plants emit 177.000 tons of CO2 and 35.000 tons of H2S.
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New regulations on H2S concentration in air requiring the geothermal industry to take action to reduce H2S emissions have resulted in a collaborative effort to find “the best solution”.
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The Icelandic energy companies have requested that that the stricter rules be delayed until 2020 to allow for time to develop a cost‐effective and environmentally friendly solution to reduce H2S emissions.
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From pilot to industrial scale in 2014. 15‐30% of the gas from Hellisheiði power plant dissolved in re‐injection water. Further steps to a proven final solution in 2020.
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Returning the H2S back to where it came from has to be considered an ideal method for reducing gas emissions from geothermal power plants.
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Thank You