CIEMAT-ATYCOS Group of the Center for Energy, Environmental and Technological Research/ Solar Platform Almeria

The main objective of the ATYCOS Unit is to store, directly or indirectly, the thermal concentrated solar energy. Directly, with the optimised design of thermal storage systems and indirectly with the chemical storage of concentrated solar energy with so-called solar fuels (reformed from Methane) and hydrogen production with thermochemical processes.

Simulation of thermocline tanks using numerical and analytical models.

In ATYCOS Thermal Storage, ATYCOS aims to develop, optimise and integrate thermal storage systems (TSS) according to the specific characteristics of the technology of the solar thermal plant.

Simulation of thermocline tanks using numerical and analytical models.

Our extensive experience, both in the testing of thermal storage prototypes – sensitive or latent -, and in the simulation of the thermohydraulic behaviour of physical systems – through our own or commercial programs – enables us to design and optimize TSSs for working temperatures above 140°C and up to 800°C. In this sense we follow a holistic approach in which integration with the solar thermal power plant plays a major role.

Thermal Storage activities cover all aspects necessary for the development, verification and optimisation of an efficient system to accumulate thermal energy:

• Proposing new materials for thermal storage and characterising some of its chemical, mechanical and thermal properties¹.
• Testing components for molten salt circuits (valves, pressure transmitters, vertical pumps, electrical swallowing, etc.).
• Designing new thermal exchangers or accumulators with well-known materials.
• Testing, even in real solar conditions, innovative thermal energy storage modules, both sensitive and latent.
• Simulating the behaviour of energy accumulators, either with our own programs or with commercial programs.
• Studying the integration of the plant storage system and its overall technical feasibility.
• Optimising storage system operating strategies to get the most out of that stored energy.

The interest in Hydrogen as an energy vector in the transport sector and the undoubted appeal presented by its clean production means that the ATYCOS Solar Fuel group is paying special interest to the production of hydrogen from concentrated solar thermal technologies at high temperature. In addition, another objective of ATYCOS is the application of concentrated solar technologies to thermochemical processes in the industry, as these are generally large consumers of thermal energy.

The lines of research in relation to hydrogen are realised in two fields of activity:

• Development of processes and technologies for the decarbonisation of fossil fuels and the recovery of fossil fuels by solar gasification, with special attention to low quality carbonous materials.
• Demonstrate on a pre-commercial scale the technical and economic feasibility of water dissociation for hydrogen production by using thermochemical cycles with concentrated solar energy.

For the development of these lines,

• Studies are carried out for the integration of industrial thermochemical processes at high temperature in central tower plants.
• Chemical balance calculations and thermodynamic and kinetic analysis of innovative thermochemical cycles, based on new materials, are performed.
• Chemical reactors with different configurations are simulated, designed and operated, both at laboratory scale and in real solar conditions: volumetric, cavity, fluidised bed, etc.

Simulation of the temperature map of a tubular reactor under concentrated solar radiation

From the experience gained with chemical reactors for hydrogen production comes a new line of research whose objective is to obtain oxygen on the Moon from regolith. The special contour conditions imposed by this line of research impose the design of innovative ultra-lightweight concentrators.

Collaborations

ATYCOS, through its experts, actively participates in several scientific networks (Energy Storage JP of EERA, Tasks II and III of the SolarPACES Agreement of the IEA, Spanish Hydrogen Association –AeH2-,) and national standardisation committees (AENOR-GT3) and (IEC- CTN 206/SC 117/GT 03 and ASME-PCT52).

Since its formation, ATYCOS has been working closely with other experts from different universities, with companies in the sector and technology centres from different autonomous communities through specific collaboration agreements.