Clean technologies for solar hydrogen production based on mixed-ferrites thermo-chemical cycle. HITERSOL

Participants: ABENGOA Hydrogen (company subsidiary of the ABENGOA group) and  CIEMAT
Contacts: M. Maynar,;  Alfonso Vidal,
Funding: 150 k€; CTA-IDEA.
Duration: June 1, 2014 – December 31, 2015

Background: Some high temperature endothermic reactions for converting solar energy to chemical fuels have been investigated around the world. Many of the activities to this point dealt with identifying, developing, and assessing improved receiver/reactors for efficient running of thermochemical processes for the production of H2. A challenging approach is investigated at the Hitersol project where the reactor used to drive the ferrites cycle is a cavity receiver using tubular reactors.

Objectives: HITERSOL is cooperation between CIEMAT-PSA, and the company Abengoa Hydrogen, established within the framework of CTA-IDEA Initiative funded by the Andalusia Community.
Hitersol pursued to develop clean technologies for solar hydrogen production based on water splitting by mixed-ferrites thermochemical cycle. To achieve this aim, an installation was designed, constructed and commissioning within a previous project named SolH2. Present collaboration pursued to complete the evaluation of a 200 kW pilot plant erected in PSA.


Fig. 1. Photograph of the reactor for SolH2 tests at CRS Plant

Achievements in 2015:  The 200kWth SOLH2 solar receiver is located in the 2nd level at 28 m height and consists of a cavity receiver in which 80 vertically oriented ceramic tubes containing commercial ferrite (Fig. 1). SolH2 facility also comprises auxiliary services, such as inert gas, water, compressed air and electricity supply and communications wiring.

Along 2015, CIEMAT carried out different activities of the project, such as construction, commissioning and implementation of the SCADA in collaboration with ABENGOA Company. A preliminary simulation of the heliostat field and the heliostats that is required with the reactor design. The results of this part of the campaign must provide information of: cycle duration, feasibility of changing the reflection angle of the heliostats with sufficient speed and realization of the necessary temperature levels in order to achieve the best performance (e.g. homogeneous flux, low spillage etc.). Some problems that remain to be resolved have already been detected (e.g. the flux directed at the central point of the reactor needs to be distributed differently to cover the needs of the peripheral points).

Main conclusions of this study were that the amount of power needed for the reaction requirements are achievable and also the restrictions of the flux distribution on the chamber becomes a limitation. At this stage, definition of the heliostats strategy is complete and operating conditions before the experimental campaigns were defined. The experimental chemical campaign is scheduled for the beginning of the next year 2016.

SolH2 – Solar-driven hydrogen production by bioethanol reforming and mixed-ferrite thermochemical cycle. Raquel Díaz Franco et al.  SolarPACES Conference, 2012 Conference Marrakech, September 11‐14, 2002.