The International Space Station ISS will receive a new element for the life support system called the “Advanced Closed Loop System” (ACLS), which recently was installed by Commander Alexander Gerst and now is being tested. A catalyst from Evonik plays an important role in the system. The ALCS was developed by Airbus for the European Space Agency (ESA) to ensure a very efficient life support system on board. The system is capable of removing exhaled carbon dioxide from the air whilst generating water and oxygen to breathe. With the commissioning of the system, it will generate about 40 percent of the fresh water required on board and thus significantly reduces the amount of water which needs to be transported from the earth to the ISS. The transport of water to the ISS is extremely expensive costing up to 60,000 Euro per liter. At the beginning of 2019, the system should be fully operational on the space station.
At the heart of the system is a Sabatier reactor, which converts carbon dioxide and hydrogen into methane and water. The oxygen needed for breathing is then obtained by electrolysis of the water produced. To make the reaction of carbon dioxide and hydrogen possible, a hydrogenation catalyst is necessary. This was jointly developed by Evonik and Airbus for the special application in the ACLS and prepared for use in the ISS in a multi-year qualification. It is a high-performance catalyst that has high-stress resistance and reliably delivers the required activity and selectivity over a long period of time, even when small quantities are used.