Hydrogen can be used for the storage and conversion of energy. Organic liquids such as cyclohexane, methylcyclohexane, and decalin are potential carriers for hydrogen. During dehydrogenation, they can release hydrogen to form their unsaturated counterparts benzene, toluene, and naphthalene. These unsaturated hydrocarbons can undergo re-hydrogenation to store hydrogen in the COx-free and reversible process.

Since the eighties scientists try to use cycloalkanes as hydrogen carrier. The realization of the processes is not yet done because high specific heat flows are required for high conversion and compact systems during the endothermic dehydrogenation. To realize the high heat flows, the use of a micro structured reactor could be a promising solution. The reaction system could also be used for heat storage under these assumptions.

The design and development of the reactor and the catalyst coating were part of the research project. Furthermore, the possibility to integrate a membrane in the micro structured system has been evaluated. Reactor modules for the separation of hydrogen from the dehydrogenation of methylcyclohexane were developed and tested. In addition, catalysts and kinetics of the hydrogenation of toluene at 300°C and 30 bar were investigated to allow an efficient heat recovery from the overall so-called Liquid Organic Reaction Cycle (LORC).

Publications:

Optimization of membrane area to catalyst mass in a microstructured membrane reactor for dehydrogenation of methylcyclohexane [in press]  .
Cholewa, M.; Zehner, B.; Kreuder, H.; Pfeifer, P.
2017. Chemical engineering and processing. doi:10.1016/j.cep.2017.10.011 

Konzept zur Chemischen Wärmespeicherung mit flüssigen organischen Hydriden  .
Wagner, C.; Cholewa, M.; Ulmer, U.; Poncette, D.; Patyk, A.; Fichtner, M.; Dittmeyer, R.; Pfeifer, P.
2017. Chemie - Ingenieur - Technik, 89 (3), 341-345. doi:10.1002/cite.201600025 

Heat storage by the dehydrogenation of methylcyclohexane - Experimental studies for the design of a microstructured membrane reactor  .
Kreuder, H.; Boeltken, T.; Cholewa, M.; Meier, J.; Pfeifer, P.; Dittmeyer, R.
2016. International journal of hydrogen energy, 41 (28), 12082–12092. doi:10.1016/j.ijhydene.2016.05.140