Corrosion Behaviour of L80 Steel Grade in Geothermal Power Plants in Switzerland

In Switzerland, deep geothermal energy can give a promising contribution to the future energy scenario. However, the expertise in operational issues of deep geothermal power plants is limited, and technical challenges, such as corrosion, are a determining factor for their reliable and long-term operation. In this work, two representative fluids of optimal geothermal conditions in Switzerland were studied. The corrosiveness of the solutions was assessed using two experimental setups that allow investigating the range of temperatures and pressures that apply to the reservoir and power plant conditions. The corrosion behaviour of API L80 steel was analyzed by means of electrochemical measurements (at 100 and 200 ∘ C ) and of gravimetric tests (at 100 ∘ C ). After the tests, the morphologies and composition of the corrosion products were obtained by scanning electron microscopy (SEM) coupled with energy dispersive X-Ray (EDX) and X-Ray diffraction (XRD). Results show that corrosion rates are significantly high at 100 ∘ C in environments with a chloride concentration of around 600 mg/L and pH around 7. The corrosion products deposited on the metal surface mainly consist of magnetite and/or hematite that might potentially form a protective layer. This study gives a first insight of the potential corrosiveness of geothermal fluids in Switzerland.

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Corrosion Behavior of Q235A Steel under Wet-Dry Cyclic Condition

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.557-559.139 ◽

2012 ◽

Vol 557-559 ◽

pp. 139-142

Author(s):

Jian Guo Liu ◽

Yan Tao Li ◽

Bao Rong Hou

Keyword(s):

Electron Microscopy ◽

Chloride Concentration ◽

Corrosion Products ◽

Drying Process ◽

X Ray Diffraction ◽

Cathodic Process ◽

X Ray ◽

Reduction Processes ◽

Cyclic Condition ◽

Scanning Electron

The corrosion processes and mechanisms of Q235A steel under wet-dry cyclic condition were studied using polarization curve compared with immersion samples, while, the corrosion morphologies and corrosion products of the steel samples were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The cathodic process of wet-dry samples was likely to be controlled not by the oxygen reduction, but rather by the reduction of corrosion products. During the drying process of the wet-dry sample, the electrolyte thickness decreased and chloride concentration increased. Oxygen would be much easier to diffuse into the interface of electrolyte/metal, which improved the cathodic reduction processes. Except for this, the rust itself took part in the reduction processes and hence increased the corrosion rate of the steel samples.

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Further Studies of the Anaerobic Corrosion of Steel in Bentonite

MRS Proceedings ◽

10.1557/proc-932-32.1 ◽

2006 ◽

Vol 932 ◽

Cited By ~ 9

Author(s):

Nick R. Smart ◽

Andrew P. Rance ◽

Liisa Carlson ◽

Lars O. Werme

Keyword(s):

Corrosion Behaviour ◽

Chloride Concentration ◽

Analytical Techniques ◽

Oxide Phase ◽

Product Layer ◽

Corrosion Products ◽

Support Structures ◽

Ferrous Ions ◽

Anaerobic Corrosion ◽

Corrosion Of Steel

ABSTRACTIn the horizontal emplacement concept (KBS-3H) for the disposal of radioactive waste, which is being developed in Sweden and Finland, copper canisters with cast iron inserts will be surrounded by bentonite buffer and mounted in perforated carbon steel support structures in boreholes within the bedrock. The groundwater will be reducing, leading to anaerobic corrosion of the ferrous material. It is important to understand both the effect of bentonite on the corrosion behaviour of the steel and the effect of the corrosion products on the performance of the bentonite. Previous work on the corrosion of steel in bentonite was extended to investigate a wider range of conditions, including the possible effects of alkaline plumes released from concrete support structures and the effect of chloride concentration and temperature on the corrosion rate of steel in bentonite. Corrosion rates were measured by collecting hydrogen produced by the anaerobic corrosion of iron. In addition, a range of analytical techniques was applied to study the composition and morphology of the corrosion products and the distribution and chemical state of the iron released into the bentonite. Comparison was also made between corrosion in compacted bentonite and artificial bentonite porewater. In the presence of bentonite, the corrosion product layer was relatively thin compared to fully aqueous conditions, probably because the ferrous ions released by corrosion exchanged with the bentonite interlayer or attached to the surface of the bentonite grains, rather than forming a separate iron oxide phase.

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Thermodynamic modelling and simulation of geothermal power plants: case studies and environmental impact

10.5194/egusphere-egu21-16182 ◽

2021 ◽

Author(s):

Vitantonio Colucci ◽

Angelo Damone ◽

Giampaolo Manfrida ◽

Daniele Fiaschi

Keyword(s):

Power Plants ◽

Liquid Mixtures ◽

Pollutant Emissions ◽

Geothermal Fluids ◽

Framework Model ◽

On Line ◽

Geothermal Power ◽

And Control ◽

Excellent Tool ◽

Complicated Task

<p>The emissions associated with Geothermal power plant (GTPP) due to geothermal fluids represents a compelling challenge addressed in the last decades. The on-line measuring of pollutants generated by GTPP might result in a complicated task to handle. Simulation of GTPP has become an excellent tool to monitor and control the emission of pollutants. In the present work, the pollutant emissions of GTPP of Hellisheidi (Island), Chiusdino, and Castelnuovo (Italy) are modelled and developed with Unisim Design R480 using well understood thermodynamical models implemented in OLI. The presence of brine in the thermodynamical models has been taken into account. Carbon dioxide, methane, and hydrogen sulfide are the chemical pollutants considered for the process simulation. The AQ framework model in OLI is being used for binary mixtures and non-condensable gas. Furthermore, for liquid mixtures containing more than two components, the MSE-SRK Thermodynamic model is desirable depending on the original geothermal fluid source. The simulation process outcome agrees with experimental data for pressure between 30 and 100 bar within 5% deviation. A systematic study of the spatial distribution of the emissions has been made for the area surrounding the GTPP. Furthermore, an economic evaluation overview has been performed to highlight the equipment needed for maintenance and tool substitution.</p>

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Corrosion analysis of copper T2 exposed to polluted atmospheres and study on prediction model

Corrosion Reviews ◽

10.1515/corrrev-2016-0068 ◽

2017 ◽

Vol 35 (1) ◽

pp. 35-46 ◽

Cited By ~ 1

Author(s):

Zhiping Zhu ◽

Xiandi Zuo ◽

Zhaohui Ying

Keyword(s):

Corrosion Rate ◽

Electrochemical Impedance ◽

Corrosion Behaviour ◽

Corrosion Products ◽

Good Prediction ◽

X Ray Diffraction ◽

X Ray ◽

Early Stages ◽

Metal Materials ◽

The Mathematical Model

AbstractThe power supply accident caused by the corrosion of metal materials in the substation has become an important issue that affects the safe operation of the power grid. The corrosion of copper T2 was the most serious. The corrosion behaviour of copper T2 in SO2- and H2S-containing atmospheric environments was investigated using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), and X-ray diffraction (XRD), and the nonequidistant grey GM(1,1) model was established of which the precision and forecast dependability were evaluated. Results indicated that the corrosion rate of copper in the SO2 environment increased in the early stages of corrosion and then gradually decreased at the later stages. In contrast, the corrosion rate of copper in the H2S environment slowly increased in the early stages of corrosion and then sharply increased at the later stages. The corrosion products in the SO2 environment consisted of cuprite (Cu2O) and brochantite [Cu4(OH)6SO4], whereas the corrosion products in the H2S environment were Cu2O and chalcocite (Cu2S). The mathematical model has good prediction dependability and higher forecast reliability.

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Sulphur and vanadium-induced high-temperature corrosion behaviour of different regions of SMAW weldment in ASTM SA 210 GrA1 boiler tube steel

High Temperature Materials and Processes ◽

10.1515/htmp-2020-0035 ◽

2020 ◽

Vol 39 (1) ◽

pp. 256-260

Author(s):

Ravindra Kumar ◽

Vinay Kumar Tewari ◽

Satya Prakash

Keyword(s):

High Temperature ◽

Weld Metal ◽

Power Plants ◽

Corrosion Behaviour ◽

Thermal Power ◽

High Temperature Corrosion ◽

Tube Steel ◽

Low Grade ◽

Shielded Metal Arc Welding ◽

X Ray

AbstractCorrosion at elevated temperature is a serious problem in running thermal power plants because of the use of low-grade fuels that contain substantial amounts of sulphur, vanadium, sodium etc. This article reports the high-temperature corrosion of weld metal and heat-affected zone (HAZ) of shielded metal arc-welding (SMAW) weldment in GrA1 steel in a molten salt (Na2SO4–60% V2O5) environment at 900°C under cyclic conditions. The thermogravimetric technique was used to observe the kinetics of corrosion. The corrosion products formed on weld metal and HAZ of SMAW welded steel were characterized by scanning electron microscopy with energy dispersive X-ray analysis (EDX) and X-ray diffraction pattern. Weld metal was found to oxidize at a higher rate than those of HAZ due to the presence of sodium and sulphur in the inner oxide scale as confirmed by EDX, and this leads to high corrosion rate (in terms of weight gain).

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In Situ EXAFS Study of Sr Adsorption on TiO2(110) under High Ionic Strength Wastewater Conditions

Minerals ◽

10.3390/min11121386 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1386

Author(s):

Arjen van Veelen ◽

Paul C. M. Francisco ◽

Nicholas P. Edwards ◽

Julian Frederick W. Mosselmans ◽

Tsutomu Sato ◽

...

Keyword(s):

Fine Structure ◽

Nuclear Power ◽

Power Plants ◽

Chloride Concentration ◽

Ex Situ ◽

X Ray ◽

Surface Precipitation ◽

Absorption Fine ◽

X Ray Absorption

In order to provide important details concerning the adsorption reactions of Sr, batch reactions and a set of both ex situ and in situ Grazing Incidence X-ray Absorption Fine Structure (GIXAFS) adsorption experiments were completed on powdered TiO2 and on rutile(110), both reacted with either SrCl2 or SrCO3 solutions. TiO2 sorption capacity for strontium (Sr) ranges from 550 ppm (SrCl2 solutions, second order kinetics) to 1400 ppm (SrCO3 solutions, first order kinetics), respectively, and is rapid. Sr adsorption decreased as a function of chloride concentration but significantly increased as carbonate concentrations increased. In the presence of carbonate, the ability of TiO2 to remove Sr from the solution increases by a factor of ~4 due to rapid epitaxial surface precipitation of an SrCO3 thin film, which registers itself on the rutile(110) surface as a strontianite-like phase (d-spacing 2.8 Å). Extended X-ray Absorption Fine Structure (EXAFS) results suggest the initial attachment is via tetradental inner-sphere Sr adsorption. Moreover, adsorbates from concentrated SrCl2 solutions contain carbonate and hydroxyl species, which results in both inner- and outer-sphere adsorbates and explains the reduced Sr adsorption in these systems. These results not only provide new insights into Sr kinetics and adsorption on TiO2 but also provide valuable information concerning potential improvements in effluent water treatment models and are pertinent in developing treatment methods for rutile-coated structural materials within nuclear power plants.

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Microstructural and chemical variation in silica-rich precipitates at the Hellisheiði geothermal power plant

Mineralogical Magazine ◽

10.1180/minmag.2014.078.6.04 ◽

2014 ◽

Vol 78 (6) ◽

pp. 1381-1389 ◽

Cited By ~ 8

Author(s):

D. B. Meier ◽

E. Gunnlaugsson ◽

I. Gunnarsson ◽

B. Jamtveit ◽

C. L. Peacock ◽

...

Keyword(s):

Amorphous Silica ◽

Power Plants ◽

Common Factor ◽

Study Data ◽

Fluid Composition ◽

Silica Layer ◽

Geothermal Systems ◽

Pipe Surface ◽

Geothermal Fluids ◽

Geothermal Power

Precipitation of amorphous silica (SiO2) in geothermal power plants, although a common factor limiting the efficiency of geothermal energy production, is poorly understood and no universally applicable mitigation strategy to prevent or reduce precipitation is available. This is primarily due to the lack of understanding of the precipitation mechanism of amorphous silica in geothermal systems.In the present study data are presented about microstructures and compositions of precipitates formed on scaling plates inserted at five different locations in the pipelines at the Hellisheiði power station (SW-Iceland). Precipitates on these plates formed over 6 to 8 weeks of immersion in hot (120 or 60ºC), fast-flowing and silica-supersaturated geothermal fluids (~800 ppm of SiO2). Although the composition of the precipitates is fairly homogeneous, with silica being the dominant component and Fe sulfides as a less common phase, the microstructures of the precipitates are highly variable and dependent on the location within the geothermal pipelines. The silica precipitates have grown through aggregation and precipitation of silica particles that precipitated homogeneously in the geothermal fluid. Five main factors were identified that may control the precipitation of silica: (1) temperature, (2) fluid composition, (3) fluid-flow regime, (4) distance along the flow path, and (5) immersion time.On all scaling plates, a corrosion layer was found underlying the silica precipitates indicating that, once formed, the presence of a silica layer probably protects the steel pipe surface against further corrosion. Yet silica precipitates influence the flow of the geothermal fluids and therefore can limit the efficiency of geothermal power stations.

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