NCG emissions due to gases produced in-situ
Geothermal fluids have a different composition and gas content depending on the geological formation of the reservoir, geographical location, fluid temperature and depth. The most common compounds present in the gases of geothermal fluids are CO2, H2S, H2, Ar, NH3, N2 and CH4. Degassing from geothermal plants occurs when a fraction of these gasses can not be reinjected into the reservoir and, therefore, is emitted in the air. The largest fraction of emissions is mainly associated with utilization (if a proper treatment system, like AMIS plant in Italy is not equipped), or maintenance operations phases and partially with the well testing/drilling. However, some low temperature geothermal systems – especially in sedimentary basins where natural gas reservoirs and the geothermal aquifers may be in hydraulic connections - can also produce thermal water with significant gas content. Therefore, degassing and its consequences are not restricted to plant emissions, but are general effects of geothermal operations. Ref Geoenvi D2,1
Informations
- Category: Environmental risks
- Id: F-6
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Phases:
- Exploitation / Development
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Consequences:
- Economic / Performance / Acceptability
- Health / Safety / Environment
Mitigation
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Prevention:
- if possible, use of technologies able to guarantee complete reinjection of the resource (liquid + NCG)
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Monitoring:
- Emission control at the plant and air quality monitoring in the surrounding environment
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Corrective measures:
- Installation of CO2 (and other gases) removal technology, use of abatement systems
- if possible, installation of dispositive to use the gases (e.g. for greenhouse)
More information is available on the project deliverable (link), or navigate on the online version.
