New project on Supercritical Carbon Dioxide power systems opens 17 positions for Early Stage Researchers across Europe

iSOP stands for Innovation in Supercritical Carbon Dioxide Power Systems. It is a four year project funded by the European Commission through the Marie Sklodovska-Curie subprogramme of Horizon Europe, the 100 billion Euro flagship R&D programme in the EU.

iSOP is an Industrial Doctoral Network (MSCA-DN-IN) coordinated by University of Seville (Prof. David T. Sánchez Martínez) and focused on different yet complementary key aspects of the technology: system integration for internally or externally heated concepts, component (turbomachinery and heat exchangers) design and manufacturing, operation, control, materials, enviro-economics… To investigate each topic, an Early Stage Researcher (Doctoral Candidate) will be recruited by two members of the consortium. This is a unique feature of this class of projects, aimed at maximising the exposure of the researchers to both scientific and industrial environments (50% of the time spent at academia and industry).

Check out the complete list of PhD topics available and the associated beneficiaries involved at the iSOP website: Link

Acknowledgement: ISOP has received funding from the European Union’s Horizon Europe research and innovation programme, Marie-Sklodowska-Curie Actions (DN-ID), under Grant Agreement No. 101073266.

Salma Salah successfully passes PhD Viva at City, University of London

As SCARABEUS heads towards the last months of the project, and research outcomes are being disseminated amongst different stakeholders, the younger researchers in the project are also achieving their scientific objectives.

This last week saw Salma Salah, a young researcher at City, University of London, successfully pass her PhD Viva. Within WP3, Salma has worked very hard on the development of the SCARABEUS turbine, in collaboration with Baker-Hughes and interacting with University of Seville to ensure seamless integration with the work carried out in WP5. Let’s have Salma presenting this with her own words:

I have been working during the last four years on a PhD research project entitled “the design and analysis of supercritical carbon dioxide axial turbines”. This research is a part of the SACARABEUS project which aims to demonstrate the application of CO2 blends for Concentrated Solar Power (CSP) plants to enable cycle efficiencies greater than 50%, and hence enhance competitiveness of CSP technologies in the energy market. Considering that the turbine efficiency significantly affects the overall plant performance, the overall aim of my research is to develop design and optimisation tools for a 100 MWe scale sCO2 multi-stage axial turbine design for concentrated solar power cycles.

Turbine design is a multi-stage process that starts with preliminary aerodynamic design and optimisation using a combination of one-dimensional mean-line design suitable loss models. These models are used to quantify the energy losses that the working fluid experiences during the expansion in the blade rows, and hence they can predict overall turbine performance. To develop a turbine design operating with CO2 blends that stands from a practical design, other considerations should be considered, such as mechanical and rotor-dynamic considerations, to ensure a turbine design withstands the applied stresses and can operate safely under the different operation conditions. Therefore, the scope of this research focused on exploring the existing design methodologies to produce a mean line design for a multi-stage axial turbine operating with CO2 blends and to investigate the validity of the loss models for non-conventional working fluids (such as CO2 and organic fluids). Within this research I worked on developing a mean-line design tool that can optimise the aerodynamic turbine performance alongside complying with rotordynamic and mechanical design criteria.

Additionally, multiple design loss models have been integrated for turbines operating with these non-conventional working fluids. Using the developed tool, the loss models have been computed for air, sCO2 and ORC turbines.

Ultimately, a 14-stage CO2/SO2 flow path has been designed for a 100 MW CSP plant and the financial feasibility of the turbine flow path has been investigated to ensure that the design stands from an economic point.”

The SCARABEUS team would like to congratulate Salma Salah on this major step in her scientific career, and also the supervisors Prof. Abdulnaser Sayma (City, University of London) and Dr. Martin White (University of Sussex) and the entire team at City, University of London. Best of luck for your future professional development Salma!

A copy of Dr. Salah’s thesis can be downloaded from the repository at City, University of London:


Very nice representation of the SCARABEUS project team at the 5th European Conference on Supercritical Carbon Dioxide Energy Systems

The 5th European Conference on Supercritical Carbon Dioxide Energy Systems was held in Prague (Czech Republic) on the 15th and 16th of March, 2023. The conference was very well organised by Prof. Dostal (Czech Technical University in Prague, Czech Republic) and Prof. Brillert (Technical University of Duisburg-Essen, Germany).

The excellent scientific programme was comprised of scientific and industrial presentations, combined with interesting keynotes and panel sessions. This unfolded in an excellent setup which enabled continuous networking and provided the younger researchers with an excellent opportunity to mix and exchange ideas with senior scientists and industrials leading the development of supercritical CO2 power systems. Amongst these Early Stage Researchers, we would like to congratulate Viktoria (TU Wien), Ettore (Politecnico di Milano) and Pablo (University of Seville) for their very good presentations, which attracted the interest of the audience.

The technical papers presented at the conference will be made available in Open-Access in the coming months. More information will be shared on the SCARABEUS website when available.


Laboratorio Energia e Ambiente Piacenza working on the socio-economic assessment of the technology

Laboratorio Energia e Ambiente Piacenza working on the socio-economic assessment of the technology



The team led by Marco Gabba at the Laboratorio Energia e Ambiente Piacenza is working on Task 5.5 of the project, focused on natural capital valuation and socio-economic assessment. To this end, Gabba’s team has set up a survey, with the objective to evaluate the advantages, costs and risks of a concentrating solar plant using a CO2-based mixture as working fluid starting from the assessments of experts / technicians in the sector, through a series of structured questions with quantitative parameters.


This is an excellent opportunity for anyone interested in contributing to and influencing the development of new generation Concentrated Solar Plants. Answering the survey takes less than ten minutes and the data collected are strictly technical, not including any personal information.

If you would like to provide your input, follow this link:


Thank you very much for your input!!!

SCARABEUS present at the Solar Helix meeting in Madrid

The Dissemination Coordinator of SCARABEUS, Prof. David Sánchez from University of Seville, has been invited to join a clustering session organized by the ASTEP project: Application of Solar Thermal Energy to Processes . ASTEP is funded by the Horizon 2020 programme of the European Commission, under Grant Agreement Ni. 884411, and its main objective is to successfully demonstrate the viability of applying solar thermal energy to partially cover heating, and heating and cooling demands on two different relevant industrial demo sites located on two different climate regions, and to further develop the implementation of solar thermal energy in industrial processes up to 400 ºC. More information about this project, coordinated by Universidad Nacional de Educación a Distancia – UNED (Spain), is available on their website:


With the aim to explore opportunities for joint dissemination and exploitation in the future, the clustering activity held on October 20th is an excellent opportunity to get acquainted with the portfolio of collaborative projects investigating how solar energy can be integrated into thermal process for the industry and to generate electric power.


Agenda of the meeting. Clustering activity scheduled at 15.00 – 16.30

SCARABEUS present at the ASME Turbo Expo conference in Rotterdam, The Netherlands

The Turbo Expo conference gathers the leading professionals in power and propulsion technologies based on rotating equipment from around the world. The conference is organized by the International Gas Turbine Institute of the American Society of Mechanical Engineers and is held annually in either Europe or North America, with an attendance of over 2000 delegates from industry, academia and government. This year, the conference was held in Rotterdam, The Netherlands, in June 13-17.


SCARABEUS was very well represented by the partners, presenting the latest progress made in each area of research:


  1. Illyes et al., Design of an Air-Cooled Condenser for CO2-Based Mixtures: Model Development, Validation and Heat Exchange Gain with Internal Microfins, Paper GT2022-82438 in Technical Session 33-05.
  2. Liao et al., Life Cycle Assessment of Innovative Concentrated Solar Power Plants Using Supercritical Carbon Dioxide Mixtures, Paper GT2022-83576 in Technical Session 33-08.
  3. Putelli et al., Preliminary Analysis of High-Temperature Corrosion of Metallic Alloys with CO2 and CO2-Based Working Mixtures for Power Plants Applications, Paper GT2022-84197 in Technical Session 33-08
  4. Abdeldayem et al., Integrated Aerodynamic and Structural Blade Shape Optimisation of Axial Turbines Operating With Supercritical Carbon Dioxide Blended with Dopants, Paper GT2022-81223 in Technical Session 33-08


In addition to this, the Dissemination Coordinator of SCARABEUS (Prof. D. Sánchez) organizer a panel session on Large R&D Project Development in Europe, along with Renaud Le Pierres (Heatric).

The technical papers will be published in Open-Access in the conference proceedings. For the panel discussion, you can contact Prof. Sánchez to get a summary presentation (

SCO2-Flex Final Event: The Role of sCO2 cycles in Europe’s future energy system

SCO2-Flex Final Event: The Role of sCO2 cycles in Europe’s future energy system

On the 16th June 2021 the Sco2-Flex project will host its final event to present the results of the project and also introduce 5 other Horizon 2020 projects working with sco2 technology. 

In the context of the EU’s energy transition, the last few years have seen the potential of supercritical CO2 (carbon dioxide) cycles emerge as an efficient replacement of steam in the cycles converting heat into power, leading to a more flexible and lower-emission electricity production.


Indeed, since they can be adapted to any type of production (from conventional production to heat recovery, including nuclear and renewable energy), sCO2 cycles offer very interesting prospects in terms of increased efficiency, flexibility, cost control and reduced environmental impact.


All over the world, numerous research projects and demonstrators are being set up, and Europe is positioning itself as one of the players in this area. The number of research projects on sCO2, financed by the European Commission, has been increasing for more than 6 years and demonstrates the dynamics of European academic and industrial actors.


Given this fact, the event proposed within the framework of the sCO2-flex project aims to show the versatility of sCO2 cycles in energy production as well as the objectives and results obtained by the actors of these European projects.

In addition to a presentation by the European Commission, 6 projects will present their vision of the potential of sCO2 cycles. They are:


Check out the full Agenda and to register please click HERE


The event will take place online from 2pm to 5pm CET.


Registrations will close on the 15th June or until hosting capacity is reached. After registering, you will be sent a link to join the online session the day before the event.

Carbon Dioxide mixtures at the 4th European sCO2 Conference for Energy Systems, Prague

The 4th edition of the European sCO2 Conference for Energy Systems, held virtually on March 23-24, gathered some forty excellent works presented by international authors. The number of attendees and quality of works presented confirmed that the sCO2 community is vibrant and the future of the technology looks bright.

A number of very interesting papers dedicated to CO2 blends triggered the interest of the SCARABEUS consortium:

  • 1 Valencia Chapi, R., Fierros-Peraza, O., Coco-Enríquez, L., Muñoz-Antón, J., Modeling and study of a printed circuit heat exchanger for Brayton power cycles using supercritical CO2 mixtures as working fluid (Universidad Politécnica de Madrid)
  • 2 Ayub, A., Di Marcoberardino, G., Invernizzi, C.M., Iora, P., Advanced thermodynamic power cycles utilizing carbon dioxide based mixtures as working fluids for high temperature waste heat recovery (University of Brescia)
  • 3 Rath, S., Mickoleit, E., Gampe, U., Breitkopf, C., Jäger, A., Study of the influence of additives to CO2 on the performance parameters of a sCO2-cycle (TU Dresden)

These added to two works by University of Seville and City, University of London, presented on behalf of the consortium:

  • Aqel, O., White, M., Sayma, A., Binary interaction uncertainty in the optimization of a transcritical cycle: consequences on cycle and turbine design (City, University of London)
  • Crespi, F., Rodríguez-de Arriba, P., Sánchez, D., Ayub, A., Di Marcoberardino, G., Invernizzi, C.M., Martínez, G.S., Iora, P., Di Bona, D., Binotti, M., Manzolini, G.,  Thermal efficiency gains enabled by using supercritical CO2 mixtures in Concentrated Solar Power applications (University of Seville, Politecnico di Milano, University of Brescia, LEAP)

Different CO2 mixtures were proposed for Concentrated Solar Power and Waste Heat Recovery applications. Rath et al. performed a vast screening of 135 candidates out which five were selected: Krypton, Xenon, Carbonyl sulfide (COS), Propane and Sulfur hexafluoride for WHR systems. For the same application, Ayub et al. studied CO2-Novec mixtures in three different layouts, concluding that a 3 percentage point gain with respect to pure CO2 seems possible. Regarding CSP, Crespi et al. investigated the use of CO2-C6F6 and CO2-TiCl4 mixtures, coming to the conclusion that it is possible for the power block to achieve and even exceed 50% thermal efficiency even under semi-arid boundary conditions, provided that the suitable cycle layout is selected for each working fluid-was achievable. Also for CSP plants, Valencia-Chapi et al. modelled a printed circuit heat exchanger and studied its performance for different CO2 mixtures, noting that heat transfer coefficients of the mixtures were higher than those of pure CO2; this favours lower heat exchang areas. Finally, the turbine of large power blocks running on CO2-C6F6, CO2-H2S and CO2-NOD (non-organic dopant) were studied by Aqel, White & Sayma.

Common to all work was the emphasis on the suitable fluid modelling of CO2 mixtures. In the work of Ayub et al., binary interaction parameters of different CO2 mixtures (Novec 5110, Novec 649, R134a, HFO1234yf and HFO1234ze(E)) were estimated using experimental VLE data from literature and then applying Peng-Robinson with Van der Walls mixing rule to estimate thermodynamic properties. The same fluid model was used by Crespi et al. for CO2-C6F6 and CO2-TiCl4 mixtures. Valencia-Chapi et al. modelled CO2 mixtures using the Aungier-Redlich-Kwong real gas model. Aqel, White & Sayma studied the influence of four different Equations of State and of the uncertainty in the estimates of binary interaction parameters on cycle performance and turbine geometry. Rath et al. use a predictive model to calculate mixture properties based on the best available EoS for the pure components.

In addition to the works by Aqel et al. and Crespi et al., which describe the latest results obtained by the SCARABEUS consortium, a series of works developed by other projects funded by the European Commission (sCO2 Hero and sCO2 Flex) were presented at the conference. Moreover, several interesting topics regarding sCO2 cycle performance, turbomachinery and heat exchanger design and novel sCO2 cycle configurations have been thoroughly discussed. The entire set of presentations and papers are available online in the conference repository ( so, if you wish to take a closer look at some of the works, just follow this link and enjoy!


Preliminary heat transfer experiments at TU Wien

One of the major goals of the SCARABEUS project is to show the feasibility of the innovative air cooled condenser (ACC) through experiments in Vienna. This heat exchanger is a crucial component in the proposed technology by enabling dry cooling in warm areas where one would typically find Concentrated Solar Power plants.

For down-sizing and thereby reducing the costs, enhanced finned tubes on the inside (CO2 side) will be used. In the course of the design process of Kelvion, experimental measurements at TU Wien are essential to evaluate the heat transfer coefficients on the CO2 side.

To do so, the existing test rig at TU Wien was modified. Originally, in the former project for which the rig was designed and constructed, this was able to perform a full Rankine cycle at a maximum CO2 temperature of 350 °C and a pressure of up to 240 bar. For the heat transfer measurements, maximum temperature and pressure were temporarily reduced, since only the low pressure side is of interest.  After the expansion valve, which represents the turbine, two heat exchangers are now located: the precooler and the test tube.

The test tube is a tube-in-tube heat exchanger of 1 m length. Water was chosen as the cooling medium. In a numerical study, Kelvion determined two types of fins considering number, height, thickness and angle of the fins. There will be three test tubes tested at TU Wien in total:

  • BARE test tube
    • Used as a reference without fins
  • COOLING test tube
    • Fins designed to enhance the heat transfer when cooling down superheated CO2
  • CONDENSING test tube
    • Fins designed to enhance the heat transfer when condensing the CO2

The precooler´s purpose is to specifically control the conditions of CO2 at the inlet of the test tube. The test conditions will cover a range of conditions we expect at the ACC in the future which will show dependencies of the heat transfer on:

  • 2 pressures
  • 3 CO2 mass flows
  • 2 CO2 inlet temperatures
  • 5 values of inlet vapor content

To show the impact of an additive on the heat transfer, the heat transfer of a blend of CO2 with R1234ze will be examined and compared to pure CO2. Based on the results the ACC will be designed.

SolarPACES 2020: SCARABEUS listed as one of the flagship R&D projects in Europe by Prof. Julián Blanco, Managing Director of the Solar Platform in Almería (PSA-CIEMAT)



This year, most conferences have made the decision to go virtual in order to circumvent the limitations on mobility brought about by COVID-19. SolarPACES has been no different in this regard but the


Wednesday’s plenary session, chaired by Ana María Ruiz Frías (Solar Committee Chile), focused on CSP Technology Innovation. All continents were represented by high-level speakers -Australia, Asia, America and China- who introduced their vision about research priorities in Concentrating Solar Power and the tools and funding schemes to enable their accomplishment.


In this session, Europe was represented by Prof. Julián Blanco, Director of Plataforma Solar de Almería (CIEMAT), largest research, development and test centre in Europe for Concentrating Solar technologies. Prof. Blanco’s presentation provided an excellent summary of the current research priorities identified by the European Commission, along with a very informative review of the ongoing research activities and flagship projects in Europe. With the aim to make the presentation comprehensive, the contents were broken down into twelve R&I areas approved by the Steering Group of the Solar Energy Technology (SET) Plan in 2017.


The SCARABEUS consortium is grateful to Prof. Julián Blanco for making the presentation available for download (link).