The RESTRUCTURE project, which officially ended in January 2016, performed the validation at a semi-pilot scale system of about 74 kWh capacity and was constructed and operated at the Juelich Solar Tower (STJ), Germany.
Although the storage capacity was relatively low, this was the first time that such a concept was validated under near-realistic conditions for thermochemical heat storage applications.
The novelty of the reactor design relates to the use of a monolithic honeycomb ceramic structure as its building block, in which the active material can be incorporated via several ways. This structure is very similar to the ceramic ‘bricks’ used in the catalyst converters in motor vehicles.
The materials used are metal oxide-based (e.g. cobalt oxide and manganese oxide). Substantial development was required within the project framework, in order to produce the full-scale redox honeycombs, and several challenges had to be confronted by the project team.
Prominent examples of such challenges included achieving a good compromise between structural stability under operating conditions and redox performance, as well as scaling-up of production strategies initially developed at a laboratory scale. However, the project consortium had already anticipated most of these challenges and in several cases developed fall-back options to be held in reserve.
The advantages that monolithic honeycomb structures can provide are related to the simpler reactor design that they can offer and the inherent modularity of such a system.
More information: http://www.heatexchanging.com