• New test facility at the Coal Innovation Centre in Niederaussem is one more module for the "Power-to-Gas" project
  • Germany's Federal Ministry of Economics and Technology is backing project under the CO2RRECT research initiative

New electrolysis technology in the Coal Innovation Centre: the delivery...

Separating water into its components hydrogen and oxygen using excess wind power: that is the aim of an innovative electrolysis system from Siemens. The novel technology comes with a so-called proton exchange membrane (PEM) and enables electric power to be converted into hydrogen. The system is currently being built up in the Coal Innovation Centre at the Niederaussem power-plant location. The electrolysis system is located in a standard container and, after commissioning, is due to be tested from January to October 2013.

The new test facility is an important component in RWE's research activities for storing power ("Power-to-Gas") and utilizing CO2. Building and trialling the system is part of the CO2RRECT research project supported by the Federal Ministry of Economics and Technology. Besides numerous research facilities, participants in the initiative include industrial partners like Bayer Technology Services, Bayer Material Science, Siemens and RWE Power. Here, experts are jointly examining how hydrogen can be produced from excess renewables-based electricity and CO2 utilized as a raw material.

The hydrogen produced by the electrolysis system can be deployed in the most varied of ways: Some of it can be used with CO2 from the power plant's flue gas to produce methane in the adjacent new catalyst test facility. As chemical energy in the form of natural gas, it can be placed in interim storage; when required, the gas can be turned into electricity or made available to the heating market. So this is trialling another, crucial step in the "Power-to-Gas" process chain under real conditions. Alternatively, the hydrogen can be used to make further chemical products, like methanol.

Dr Ulrich Hartmann, RWE Power Board member responsible for Research and Development, explains: "Renewables often generate more electricity than is consumed when energy demand happens to be low", adding "At our Coal Innovation Centre, we are investigating various ways of storing and using this excess energy. That is becoming more and more important as renewables go on growing if this energy is to be called at night or when there's a lull in the wind, say."

Within the scope of the test programme, RWE Power's engineers are examining with real operating profiles how fluctuations in renewable sources can be offset by storing electricity. One of the research focuses is on investigating the effect of frequent load changes on the functioning of the electrolysis system and on the hydrogen quality obtained.

This is how the conversion of electric energy into hydrogen works:

At the core of the new electrolysis technology is a so-called proton exchange membrane (PEM).

In the electrolyser, this proton-permeable membrane separates the areas in which oxygen and hydrogen emerge. Fitted at the front and back of the membrane are precious-metal electrodes which are connected to the positive and negative poles of the voltage source. The water is split at the electrodes.

Thanks to this membrane technology, PEM electrolysis can respond to the fluctuating electricity supply from renewable sources within milliseconds. Such fast response times are achieved by combining the PEM's properties with innovative industrial control technology.

Contact for inquiries:
Laura Hoeboer
Press, RWE Power AG
T: +49 / 201/12-22342

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