Periodic Reporting for period 2 - COMPASsCO2 (COMPONENTS’ AND MATERIALS’ PERFORMANCE FOR ADVANCED SOLAR SUPERCITICAL CO2 POWERPLANTS)
Reporting period: 2022-05-01 to 2023-10-31
COMPASsCO2 addresses the challenge of developing high performance materials and combined components to withstand extreme and varying conditions that are expected in future processes, and improve their target performance for a long time, as the main scope of H2020’s topic LC-SPIRE-08-2020. Energy conversion systems that are more efficient and make use of renewable sources of energy are highly required for the energy policy goal of the European Union of achieving decarbonization of the power sector by 2050. Current state-of-the-art concentrated solar power (CSP) plants include solar towers with molten salt and parabolic trough plants with thermal oil; having temperature limitations of 565 and 400 °C respectively. A path to increase the efficiency of the overall plant is to use highly efficient supercritical CO2 Brayton cycles with a CSP plant operating with solid particles above 900 °C. The conditions at the plants' interface, the particle/sCO2 heat exchanger, are extreme in terms of temperature, pressure, abrasion, corrosion, erosion, oxidation and carburization. COMPASsCO2 aims to develop, test and demonstrate new materials for the solid particles in the CSP plant and structural materials for the heat exchanger tubes, demonstrating its lifetime by measurement and modelling methods.
sCO2 Brayton cycles selected for the highest efficiency. Solar plant and particle-sCO2 heat exchanger (HX) designed and the selection of particles and structural materials to withstand high temperature and pressure.
Characterization and durability testing of 10 different particles types has been conducted. In addition, 3 coating types have been developed and deposited on the third and fourth generation of granulated particles. Based on the collected data, the fourth generation of granulated particles has been selected for commercialization and were named FerOx.
The selected state-of-the-art materials have been mechanically tested from room to high temperatures (up to 900 °C). Preliminary mechanical and oxidation performance of novel Cr-NiAl alloys, Cr-Cr3Si alloys, and coatings were investigated (D3.1&D3.2). Bulk Cr-NiAl alloys and the Cr-Cr3Si coating were selected for onward environmental testing in WP4. Sample coupons have been made and delivered (D3.3&MS11). Modelling was conducted to understand the structure-property relations of the Cr-based alloys and designs to improve their ductility (D3.4).
The heat exchanger tubes and their interaction with the sCO2 on the process side and air and ceramic particle contact on the exterior are being tested and modelled in WP4. The exposures in air and CO2, erosion by particles and creep tests in air and CO2 are informing the material lifetime predictions and allowing a ranking of the potential structural materials.
Cold test experiments were performed. Obtained experimental data were evaluated and used for designing of mock-up heat exchanger. The mock-up heat exchanger detail design is almost finished and the materials for its manufacturing purchased. Particle transport system, as well as the electrical heaters were designed, manufactured and verified under high temperature conditions. Particle mass flow meter was developed and tested. The particle loop has been manufactured, commissioned and it is ready for long-tem abrasion test. Newly developed particles were produced and delivered and are ready for following experiments. Most of samples for the abrasion test were manufactured and preprocessed and the experiment is going to start in next weeks.
The results of the project have been communicated and disseminated through a wide stakeholders' group. A comprehensive communication strategy with specific communication tools, including the visual identity, leaflet, website, etc. was produced. The website has been serving as the main communication and dissemination platform through which all updates related to COMPASsCO2 has been regularly announced. Social media tools have been used, namely LinkedIn and X (former Twitter). Six issues of the newsletter were produced (three during each period). Synergies with sister projects working on sCO2 and novel materials were carried out, including the participation in three webinars. Two Stakeholders Workshop were organized to introduce the project, discuss the main research activities conducted, validate the results and identify areas in which to cooperate with the different stakeholders. COMPASsCO2 team participated actively in several highly attended conferences (like SolarPACES, MRS, TMS, FEMS EUROMAT, ACHEMA, etc.) to disseminate the results, with 29 presentations. 4 scientific papers have been produced. 13 Key Exploitable Results have been identified so far. The Data Management Plan (D7.5) was developed in Feb 2021 and was updated after the first reporting period, with more new datasets.
Characterization and durability testing of 10 different particles types has been conducted. In addition, 3 coating types have been developed and deposited on the third and fourth generation of granulated particles. Based on the collected data, the fourth generation of granulated particles has been selected for commercialization and were named FerOx.
The selected state-of-the-art materials have been mechanically tested from room to high temperatures (up to 900 °C). Preliminary mechanical and oxidation performance of novel Cr-NiAl alloys, Cr-Cr3Si alloys, and coatings were investigated (D3.1&D3.2). Bulk Cr-NiAl alloys and the Cr-Cr3Si coating were selected for onward environmental testing in WP4. Sample coupons have been made and delivered (D3.3&MS11). Modelling was conducted to understand the structure-property relations of the Cr-based alloys and designs to improve their ductility (D3.4).
The heat exchanger tubes and their interaction with the sCO2 on the process side and air and ceramic particle contact on the exterior are being tested and modelled in WP4. The exposures in air and CO2, erosion by particles and creep tests in air and CO2 are informing the material lifetime predictions and allowing a ranking of the potential structural materials.
Cold test experiments were performed. Obtained experimental data were evaluated and used for designing of mock-up heat exchanger. The mock-up heat exchanger detail design is almost finished and the materials for its manufacturing purchased. Particle transport system, as well as the electrical heaters were designed, manufactured and verified under high temperature conditions. Particle mass flow meter was developed and tested. The particle loop has been manufactured, commissioned and it is ready for long-tem abrasion test. Newly developed particles were produced and delivered and are ready for following experiments. Most of samples for the abrasion test were manufactured and preprocessed and the experiment is going to start in next weeks.
The results of the project have been communicated and disseminated through a wide stakeholders' group. A comprehensive communication strategy with specific communication tools, including the visual identity, leaflet, website, etc. was produced. The website has been serving as the main communication and dissemination platform through which all updates related to COMPASsCO2 has been regularly announced. Social media tools have been used, namely LinkedIn and X (former Twitter). Six issues of the newsletter were produced (three during each period). Synergies with sister projects working on sCO2 and novel materials were carried out, including the participation in three webinars. Two Stakeholders Workshop were organized to introduce the project, discuss the main research activities conducted, validate the results and identify areas in which to cooperate with the different stakeholders. COMPASsCO2 team participated actively in several highly attended conferences (like SolarPACES, MRS, TMS, FEMS EUROMAT, ACHEMA, etc.) to disseminate the results, with 29 presentations. 4 scientific papers have been produced. 13 Key Exploitable Results have been identified so far. The Data Management Plan (D7.5) was developed in Feb 2021 and was updated after the first reporting period, with more new datasets.
A conceptual design of a solar plant including a solar tower, a supercritical CO2 Brayton cycles and a particle-sCO2 heat exchanger (HX) was developed. The HX design provides a general arrangement for an industrial-scale viable solution at the end of the project. The key impact refers mainly to the knowledge of materials to be used in the HX with a broad assessment of their lifetime. It would therefore increase the TRL from 3 up to 5 validating the developed concept in industrially relevant conditions.
FerOx particles seem to exceed the performance of state-of-the-art particles proppants: while maintaining same cost range, mechanical properties and energy density, they show superior softening temperature and better thermal stability. Three types of coatings have been deposited on FerOx, reaching solar absorptance up to 97% (the state of the art is about 85%).
Two peer-reviewed papers on Cr-NiAl alloys were published, and Cr-Cr3Si coating has been patented. UoB Experiment +VTT modelling has been presented in EUROMAT2023, and will be published in an onward paper. A further paper on the Cr-Cr3Si alloys and coating will be submitted in next period. The high-quality scientific research work in the period has successfully achieved top scientific papers and conference engagement. Results of the environmental testing on bulk/coated materials will further advance materials development for CSP.
SOTA materials have been tested and their application range for the CSP plant with particles and sCO2 is being determined. Beyond the SOTA alloys, novel coatings and new alloys with enhanced properties are being tested and compared with the SOTA materials. These novel materials will be fully characterized and have potential to be commercialized for other high temperature applications, e.g. turbines, molten salts.
The efficiency and the feasibility of high temperature heat exchanger (HX) with the target sCO2 temperature of 700°C will be verified. It will lead to efficiency increase of the solar thermal power systems integrating energy storage. The flow field of solid particles in the HX bundle was studied in detail and important parameters for future design of solid particles heat exchangers were reached. Air particle-transport system and unique electrical heater, which are well applicable for further experimental facilities were developed and verified.
FerOx particles seem to exceed the performance of state-of-the-art particles proppants: while maintaining same cost range, mechanical properties and energy density, they show superior softening temperature and better thermal stability. Three types of coatings have been deposited on FerOx, reaching solar absorptance up to 97% (the state of the art is about 85%).
Two peer-reviewed papers on Cr-NiAl alloys were published, and Cr-Cr3Si coating has been patented. UoB Experiment +VTT modelling has been presented in EUROMAT2023, and will be published in an onward paper. A further paper on the Cr-Cr3Si alloys and coating will be submitted in next period. The high-quality scientific research work in the period has successfully achieved top scientific papers and conference engagement. Results of the environmental testing on bulk/coated materials will further advance materials development for CSP.
SOTA materials have been tested and their application range for the CSP plant with particles and sCO2 is being determined. Beyond the SOTA alloys, novel coatings and new alloys with enhanced properties are being tested and compared with the SOTA materials. These novel materials will be fully characterized and have potential to be commercialized for other high temperature applications, e.g. turbines, molten salts.
The efficiency and the feasibility of high temperature heat exchanger (HX) with the target sCO2 temperature of 700°C will be verified. It will lead to efficiency increase of the solar thermal power systems integrating energy storage. The flow field of solid particles in the HX bundle was studied in detail and important parameters for future design of solid particles heat exchangers were reached. Air particle-transport system and unique electrical heater, which are well applicable for further experimental facilities were developed and verified.