Objective
The aim of the project is to increase the electric power generation of Latera geothermal plant by means of a turbine expander, recovering the pressure energy from the NCG (noncondensable gas), mainly consisting of CO2, separated from the geothermal fluid.
While the technology of natural gas expansion, also by means of turbine expanders, is proven, this project is aimed at the demonstration of the possibility to obtain a consistent and reliable energy generation by the expansion of a stream of geothermal gases. A tailored approach is required, due to the chemical and physical characteristics of the NCG, substantially differing from the ones of natural gas.
The proposed plant consists of a new expansion line, where a single-stage turbine is fed by the NCG separated by the geothermal fluid upstream from the steam turbine.
The new turbine expander shall drive an asinchronous generator, producing a peak power of around 4200 kW, with an average generation capacity of 2450 kW over 12 years, the lifetime of the project. This additional net power will be generated in addition to the 26 MW generated by the geothermal plant, now under construction, without any increase of fluid consumption. Some 10% increase in the electricity generation will thus be obtained, with a corresponding increase in the efficiency of fluid utilization. The installation of the turbine expander is made possible by the particular scheme of the geothermal plant, entailing NCG separation upstream of the steam turbine by means of a direct-contact "reboiler" (a sort of pressure condenser fed by the flashed steam with high NCG content separated at wellhead). This solution was chosen as it allows a net higher efficiency of the geothermal plant in comparison with other schemes, where the geothermal steam with high NCG content is directly fed to the turbine.
The new expansion line includes a fillter for the turbine expander protection (liquid particles present before the turbine inlet must be removed), a thermal-flow computer (for the assessment and monitoring of the performances) and the single-stage turbine, coupled to an induction-type asynchronous generator.
The line is fitted with a by-pass, to allow NCG discharge to the atmosphere whenever required, as in case of signals coming from the control system of the expander.
The sue of a turbine expander with geothermal NCG has no previous application worldwide. The calculated yearly value of the energy recovered by the expander to conventional installations, amounts to 1470 Mlit.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectrical engineeringelectric energy
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringcontrol systems
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectrical engineeringpower engineeringelectric power generation
- engineering and technologyenvironmental engineeringenergy and fuelsfossil energynatural gas
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Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
56122 Pisa
Italy