Specific chemical processes are capable to store solar high temperature heat above 400 °C in the form of solar fuels and other chemical substances. The Thermochemistry Lab of CeraStorE® offer technical equipment fort he investigation of such processes. The development start off from functional materials, in particular from redox materials, and proceeds to the realization of key components essential for the technical validation of the solar-chemical process of interest. Innovative concepts based on the one hand on particle technology and on the other hand on porous monolithic ceramic structures are being tested in practice.
For most of the tests the use of high power high temperature furnaces is meaningful. Depending on the scientific target the size of the sample containing chamber or the heating rate can be important parameters. In the thermochemistry the following equipment is available:
Chamber furnaces are ideally suitable for the synthesis of innovative redox materials or for the sintering of larger structures of material. Tube Furnaces often are the core part of test set-ups which serve to investigate the properties of redox materials and catalysts. A primary interest of DLR’s solar researcher is the reactions of such material with gases like air, steam or carbon dioxide.
E.g. in the case of solar thermochemical water splitting, a core reaction for Solar Fuels Production, water vapour is reacted with redox materials. The resulting products oxygen and hydrogen are quantitatively analysed. For the control and analysis of the products the following equipment is used:
A complex test bench for the analysis and evaluation of long-term performance of sulfuric acid splitting catalystshas been developed and is available for dedicated tests. A specific safety strategy and procedure enables continuous testing even overnight and over weekends. By using this test bench catalysts have been continuously tested over periods of more than 5000 hours in a row.
Catalyst benchmarking for solar sulfuric acid splitting. Source: DLR
The screening of redox material is carried out via thermogravimetric analyses (TGA). Core part of the TGA is a thermobalance allowing to determine mass changes depending on temperature. In combination with monitoring changes of gas phase compositions that way thermochemical process can be excellently simulated. The activity of the materials can be precisely correlated to a corresponding mass change.
The thermochemistry lab offers a high performance thermobalance connected to a mass spectrometer and to an oxygen pump with integrated lambda sensor.