TY - CONF A1 - Ackermann, H. A1 - Bäßler, Ralph A1 - Diarra, D. A1 - Weltschev, Margit T1 - Entwicklung einer Prüfmethode zur Bewertung der Materialbeständigkeit von Bauteilen in Mitteldestillatanwendungen N2 - Damit stehen neben den klassischen (Massenänderung der Werkstoffprüfkörpern und metallographischer Bewertung) neue Auswertemethoden für die Werkstoffbewertung zur Verfügung. T2 - DGMK Projekttreffen CY - Hamburg, Germany DA - 28.02.2018 KW - Korrosion KW - Brennstoff PY - 2018 AN - OPUS4-44932 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Ackermann, H. A1 - Pötzsch, Sina A1 - Weltschev, Margit A1 - Bäßler, Ralph A1 - Plum, W. T1 - Entwicklung einer Prüfmethode zur Bewertung der Materialbeständigkeit von Bauteilen in Mitteldestillatanwendungen N2 - Im Vorhaben wurde eine forcierte Prüfmethode zur Bestimmung der Beständigkeit von metallenen Werkstoffen gegenüber Brennstoffen aus Mitteldestillaten und Gemischen aus Mitteldestillat und paraffinischen Kohlenwasserstoffen, die jeweils Fettsäuremethylester (FAME) als biogene Komponente enthalten, entwickelt. Bei der Prüfmethode werden Prüfkörper des jeweiligen Werkstoffes in speziellen Prüfmedien ausgelagert. Die Zusammensetzung von zwei Prüfmedien wurde im Vorhaben erarbeitet. Diese Prüfmedien erfassen die Effekte der Alterung des FAME, die zu erwarten sind, wenn der Brennstoff länger als 2 Jahre im Feld lagert. Sie decken den Bereich bis 20 % (V/V) FAME-Anteil ab. Die Auslagerung kann bei geringem Aufwand unter Atmosphärendruck durchgeführt werden. Die Eignung einer Auswahl von metallenen Werkstoffen und Polymerwerkstoffen, die für Versorgungsanlagen für Mitteldestillat relevant sind, wurde durch Auslagerung in folgenden nicht gealterten Brennstoffen bestimmt: Heizöl EL schwefelarm (B0), Heizöl EL schwefelarm mit 20 % (V/V) FAME (B20), FAME (B100) und hydriertes Pflanzenöl (HVO). Die Werkstoffe wurden auch in einem 1 Jahr gealterten B20 und einem 8 Jahre gealtertem B10 ausgelagert. Die Temperatur bei der Auslagerung betrug 50 °C für die metallenen Werkstoffe und 40 °C und 70 °C für die Polymerwerkstoffe. Die Ergebnisse der Beständigkeitsbewertung wurden in Beständigkeitslisten zusammengefasst. Die mit B20 erhaltenen Bewertungen gelten generell für Gemische aus Heizöl EL schwefelarm und FAME mit einem FAME-Gehalt bis 20 % (V/V). Sie sind auch auf Gemische aus Dieselkraftstoff und FAME mit einem FAME-Gehalt bis 20 %(V/V) übertragbar. Die forcierte Prüfmethode kann insbesondere KMUs bei der Weiterentwicklung von bestehenden Produkten und der Entwicklung von neuen Produkten als ein kostengünstiger Schnelltest zur Überprüfung der Werkstoff- und Bauteilbeständigkeit gegenüber Mitteldestillaten mit hohem FAME-Anteil dienen. Sie kann für die Hersteller die Sicherheit erhöhen, dass Bauteile die Freigabeprüfungen der Bauaufsicht bestehen, wobei die Freigabe jedoch nur für Deutschland gültig ist. Die Erkenntnisse des Forschungsvorhabens können in eine harmonisierte Europäische Norm für alternative Brenn- und Kraftstoffe einfließen. Diese ist für die Bauteilhersteller die Voraussetzung für die Erschließung des europäischen Marktes.   N2 - Within this project, a forced test method was developed to determine the resistance of metallic materials to middle distillate fuels and mixtures of middle distillate and paraffinic hydrocarbons both with fatty acid methyl ester (FAME) as a biogenic component. In the method, specimens of the material are immersed in special test media. The compositions of two test media were developed within the project. These test media include the influence of aging of the FAME which is to be expected after a storage of the fuel exceeding 2 years in the field. They cover a range of up to 20 % (v/v) FAME content. The exposure test can be carried out at ambient pressure with little effort. Suitability of selected metallic and polymer materials relevant for middle distillate supply systems was determined by exposure to the following non-aged fuels: low-sulfur light fuel oil (B0), low-sulfur light fuel oil with 20 % (v/v) FAME (B20), FAME (B100) and hydrogenated vegetable oil (HVO). The materials were also exposed in the 1-year-aged B20 and 8-year-aged B10. Test temperature was 50 °C for metallic materials and 40 °C and 70 °C for polymers. Resulting materials resistances were summarized in resistance tables. Resistances obtained in B20 are valid for any mixture of low-sulfur light fuel oil and FAME containing up to 20 % (v/v) FAME. They are also transferable to mixtures of diesel and FAME having a FAME content of up to 20 % (v/v). This method with special test media is a cost-effective rapid test for checking resistance of materials to middle distillates having a high FAME content. It can support SMEs manufacturing components for supply systems in further development of existing and new products. It increases the manufacturers' certainty that components will pass approval tests of authorities. Results of this research project can be incorporated into a harmonized European standard for alternative fuels. This is the prerequisite for component manufacturers to access the European market. KW - Heizöl KW - FAME KW - Biobrennstoff PY - 2020 UR - https://dgmk.de/publikationen/ SN - 978-3-947716-14-2 SN - 0937-9762 SP - 1 EP - 153 PB - DGMK CY - Hamburg AN - OPUS4-51110 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, G. A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Roth, C. T1 - The Effect of Different Polyaniline Types in Silicon Dioxide Containing Coatings for Carbon Steel Protection in Artificial Geothermal Brines N2 - According to the results of the experiments carried out, the following points can be concluded: 1. Exposure tests showed that specimens with the addition of SiO2 particles and polyaniline particles exhibit better corrosion resistance than specimens with the addition of only polyaniline particles or binder only. 2. Open circuit potential measurements showed that in the beginning of the experiments, both coatings had an open circuit potential 100 mV higher than carbon steel. Within one day of immersion, the potential of carbon steel increased significantly, indicating the formation of oxide layer. After extended exposure the carbon steel potential sat between PS1 (which had higher potential) and PS2 (which had a lower potential) and all three were in the range –600 mV to –500 mV vs Ag/AgCl. 3. Both coatings PS-1 and PS-2 were degraded with increasing exposure time, shown by the decrease of absolute impedance value at low frequency range after 2, 4, and 6 days exposure. 4. Potentiodynamic test was performed after 3 hours and 6 days exposure, and it was shown that the coating in the initial stage exhibited more passive behavior than the specimens exposed for 6 days. T2 - NACE International Corrosion Conference 2019 CY - Nashville, TN, USA DA - 24.03.2019 KW - Geothermal KW - Coating KW - Polyaniline KW - Corrosion PY - 2019 SP - 13121-1 EP - 13121-14 PB - NACE International CY - Houston AN - OPUS4-47913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Bäßler, Ralph T1 - A Coating System for Corrosion Protection of Carbon Steel as an Alternative for High Alloyed Materials N2 - Corrosive geothermal brines are a major challenge to geothermal power-plants. For cost reasons, plant designers favorize low alloyed steels, e.g., carbon steel, which are susceptible to uniform and localized corrosion when exposed to geothermal brines having acidic and saline properties. To solve such problem, coatings or inhibitors would be a protective solution as an alternative to the use of high alloyed materials. This study investigated a coating system consisting of polyaniline/silicon dioxide basing on locally available resources. Protection against corrosion of carbon steel is shown by long-term exposure and electrochemical tests of coated carbon steels, performed in an artificial acidic and saline geothermal brine, comparable to real conditions at a site in Indonesia. Therefore, an integrated coating system is presented for corrosion protection, combining the electro-chemical functionality of polyaniline and the physical advantages of silica. T2 - European Geothermal Congress CY - Berlin, Germany DA - 17.10.22 KW - Corrosion KW - Geothermal KW - Coatings KW - Polyaniniline KW - Silicate PY - 2022 SP - 1 EP - 7 CY - Berlin AN - OPUS4-56085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aristia, Gabriela A1 - Bäßler, Ralph A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Kohl, Anka T1 - Short-term exposure tests of ɣ-Al2O3 Sol-gel coating on X20Cr13 in artificial geothermal waters with different pH N2 - The suitability of an Al2O3 coating for corrosion protection on X20Cr13 was evaluated in various artificial geothermal brines, focusing on the influence of different pH (4, 6 and 8) and their chemical compositions on the coating properties. All experiments were performed in the laboratory using autoclaves at 150 ◦C and 1 MPa in deaerated condition for 1 and 7 days. Results showed that the pH of geothermal waters is the most detrimental factor in the transformation of ɣ-Al2O3 and its protective abilities. Delaminations were found in the Coating exposed to geothermal brines with pH 4. FTIR spectra indicated a transformation of ɣ-Al2O3 to boehmite AlOOH after exposure to pH 4 and 6, and bayerite Al(OH)3 was formed after exposure to pH 8. Different Crystal structures of the hydrated Al2O3 also contribute to the stability of the coatings, observed by the SEM- EDX of the surface and cross-section of coatings. This study indicated that ɣ-Al2O3 sol-gel coating presents a promising aspect of corrosion protection in geothermal environment with a neutral pH. KW - Al2O3 KW - Corrosion KW - Coating KW - Martensitic steel PY - 2021 DO - https://doi.org/10.1016/j.geothermics.2021.102193 SN - 0375-6505 VL - 96 SP - 102193 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-52931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Bäßler, Ralph A1 - Roth, C. T1 - Polyaniline/silicon dioxide containing coating for use in artificial geothermal brines N2 - Geothermal brine is a complex system containing a wide variety of dissolved salts resulting from the condition s in a geothermal well. These fluids lead to corrosion in pipes and other parts of geothermal system construction and necessitate intense research efforts in finding new suitable materials. Carbon steel is susceptible to corrosion in geothermal brine especially when it is exposed to a high temperature and high-pressure medium, which is considered to be an aggressive environment. An artificial geothermal water, bas ed on a brine composition found in Indonesia, was used to investigate the performance of high alloyed materials. The electrolyte has pH 4 and contains 1,500 mg/l Cl-, 20 mg/l SO4 2-, 15 mg/l HCO3 -, 200 mg/l Ca 2+, 250 mg/l K+, and 600 mg/l Na+. In order to protect the bare material in geothermal application, it is necessary to either use high alloyed material s or coatings. In this research, a coating system consisting of polyaniline and silicon dioxide was investigated regarding its behavior to protect carbon steel. In detail, the effect of SiO2 and polyaniline (PANi) addition was evaluated by exposure and electrochemical tests for 7 days, i.e. electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP ) at room temperature and 150 °C with 1 MPa pressure . T2 - NACE International Annual Corrosion Conference CY - Phoenix, AZ, USA DA - 15.04.2018 KW - Geothermal KW - Coating KW - SiO 2 KW - Polyaniline KW - Corrosion PY - 2018 SP - 10708, 1 EP - 14 PB - Omnipress CY - Houston AN - OPUS4-44916 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Electrochemical deposition of polyaniline on carbon steel for corrosion study in geothermal solution N2 - Polyaniline has been widely developed for many applications, e.g. sensor, supercapacitor components, electrochromic devices, and anticorrosion pigments. Although the addition of polyaniline pigment in organic coatings has been an alternative for corrosion protection in industrial applications, the protection mechanism is still not fully understood. Herein in this study, as a part of the development of polyaniline/silicon dioxide coating for geothermal application, polyaniline has been deposited electrochemically on carbon steel surface in oxalic acid medium and tested in geothermal solution to understand the contribution of polyaniline to the corrosion protection of a polyaniline-based composite in the geothermal system. To observe the surface/interface reaction between the electrolyte and electrode surface during the electrochemical polymerization, electrochemical impedance spectroscopy (EIS) was applied after each cycle. For corrosion study in the geothermal application, an artificial geothermal solution was used with the composition of 1,500 mg/l Cl⁻, 20 mg/l SO₄²⁻, 15 mg/l HCO₃⁻, 200 mg/l Ca²⁺, 250 mg/l K⁺, and 600 mg/l Na⁺, and pH 4 to simulate a geothermal brine found in Sibayak, Indonesia. An electrochemical measurement was performed by monitoring the open circuit potential over seven days, with the interruption by EIS every 22 hours. The experiments were performed at room temperature and 150 °C (1 MPa) in an oxygen-free environment. Impedance spectra showed a reduction of the total impedance value of approximately 10 times for specimens measured at 150 °C compared to the specimens measured at room temperature, suggesting a less stable layer at high temperature. KW - Corrosion KW - Electrochemical deposition KW - Polyaniline PY - 2019 DO - https://doi.org/10.4028/www.scientific.net/MSF.966.107 SN - 1662-9752 VL - 966 SP - 107 EP - 115 PB - Trans Tech Publications Ltd CY - Zürich AN - OPUS4-48776 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Study of Polyaniline/Silicon Dioxide based Coating on Carbon Steel in Artificial Geothermal Brine N2 - Geothermal brines are corrosive in nature because of their salt contents and high temperatures. Therefore, they pose a major challenge to geothermal power-plants, which are mostly built of low alloyed steels, e.g., carbon steel. Carbon steel is susceptible to uniform and localized corrosion when exposed to geothermal brines having acidic-saline properties. To overcome this limitation, geothermal power plants should be built by either high alloyed materials or by integrating protection systems on carbon steel, such as coatings and inhibitors. We studied a coating system containing polyaniline/silicon dioxide basing on locally available resources that provides protection against corrosion of carbon steel and enhance the thermal resistance in geothermal environments. Here, exposure and electrochemical tests of coated carbon steels were performed in an artificial geothermal brine. The solution had a pH of 4, with the composition of 1,500 mg/L of chlorides, which is based on the chemical analysis of geothermal brine found in Sibayak, Indonesia. All exposure tests were conducted using autoclaves at 150 °C with a total pressure of 1 MPa, which was performed for up to six months to evaluate the durability of the coating system. Post-experimental analyses were performed by assessing the surface of specimens using optical and electron microscopes. On the other hand, electrochemical tests were performed for seven days at 25 °C and 150 °C to investigate the kinetics of electrochemical reactions by measuring open circuit potential and electrochemical impedance spectra. Experimental results showed the corrosion resistance of PANI/SiO2 composite coatings, where polyaniline and SiO2 play their roles as stabilizers. T2 - World Geothermal Congress CY - Online meeting DA - 30.03.2021 KW - Coatings KW - Corrosion KW - Polyaniline KW - Sibayak KW - SiO2 PY - 2021 SP - 1 EP - 7 AN - OPUS4-52830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Effect of CO2 gas on carbon steel corrosion in an acidic-saline based geothermal fluid N2 - Geothermal energy is one of the most promising energy resources to replace fossil fuel. To extract this energy, hot fluids of various salts and gases are pumped up from a geothermal well having a certain depth and location. Geothermal wells in volcanic regions often contain highly corrosive CO2 and H2S gases that can be corrosive to the geothermal power-plants, which are commonly constructed of different steels, such as carbon steel. This research focuses on the corrosion behaviour of carbon steel exposed to an artificial geothermal fluid containing CO2 gas, using an artificial acidic-saline geothermal brine as found in Sibayak, Indonesia. This medium has a pH of 4 and a chloride content of 1,500 mg/L. Exposure tests were conducted for seven days at 70 °C and 150 °C to simulate the operating temperatures for low and medium enthalpy geothermal sources. Surface morphology and cross-section of the specimens from the above experiments were analysed using scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Electrochemical tests via open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) were performed to understand the corrosion processes of carbon steel in CO2-containing solution both at 70 °C and 150 °C. Localized corrosion was observed to a greater extent at 70 °C due to the less protectiveness of corrosion product layer compared to that at 150 °C, where FeCO3 has a high corrosion resistance. However, a longer exposure test for 28 days revealed the occurrence of localized corrosion with deeper pits compared to the seven-day exposed carbon steel. In addition, corrosion product transformation was observed after 28 days, indicating that more Ca2+ cations incorporate into the FeCO3 structure. T2 - EUROCORR 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Carbon steel KW - CO2 KW - EIS KW - Geothermal KW - Corrosion PY - 2019 SP - Paper 200245, 1 EP - 5 CY - Madrid, Spain AN - OPUS4-49099 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Bäßler, Ralph T1 - Study of Al2O3 Sol-Gel Coatings on X20Cr13 in Artificial North German Basin Geothermal Water at 150 °C N2 - Al2O3 has been widely used as a coating in industrial applications due to its excellent chemical and thermal resistance. Considering high temperatures and aggressive mediums exist in geothermal systems, Al2O3 can be a potential coating candidate to protect steels in geothermal applications. In this study, γ-Al2O3 was used as a coating on martensitic steels by applying AlOOH sol followed by a heat treatment at 600 °C. To evaluate the coating application process, one-, two-, and three-layer coatings were tested in the artificial North German Basin (NGB), containing 166 g/L Cl−, at 150 °C and 1 MPa for 168 h. To reveal the stability of the Al2O3 coating in NGB solution, three-layer coatings were used in exposure tests for 24, 168, 672, and 1296 h, followed by surface and cross-section characterization. SEM images show that the Al2O3 coating was stable up to 1296 h of exposure, where the outer layer mostly transformed into boehmite AlOOH with needle-like crystals dominating the surface. Closer analysis of cross-sections showed that the interface between each layer was affected in long-term exposure tests, which caused local delamination after 168 h of exposure. In separate experiments, electrochemical impedance spectroscopy (EIS) was performed at 150 °C to evaluate the changes of coatings within the first 24 h. Results showed that the most significant decrease in the impedance is within 6 h, which can be associated with the electrolyte penetration through the coating, followed by the formation of AlOOH. Here, results of both short-term EIS measurements (up to 24 h) and long-term exposure tests (up to 1296 h) are discussed. KW - Al2O3 KW - Geothermal KW - Martensitic steels KW - Behmite KW - Corrosion PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-525551 DO - https://doi.org/10.3390/coatings11050526 SN - 2079-6412 VL - 11 IS - 5 SP - 526 PB - MDPI CY - Basel AN - OPUS4-52555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -