Utilizing Bosch Generated Carbon for Additive Manufacturing

For long duration life support missions, oxygen recovery from metabolic CO2 is essential. Currently, the ISS oxygen recovery system is capable of recovering approximately 50% of the oxygen from metabolic carbon dioxide. However, for long duration manned missions, a minimum of 75% with a target of 90% of oxygen recovery is required. Theoretically, the Bosch process can recover 100% of oxygen from metabolic CO2, making it a desirable technology for oxygen recovery for long duration missions. The Bosch process reacts carbon dioxide (CO2) with hydrogen (H2) to produce water (H2O) and elemental carbon (C) in the presence of a catalyst. The water that is produced in the Bosch process is fed to the Oxygen Generation Assembly (OGA) where it is then electrolyzed to form gaseous H2 and O2. H2 is recycled back to the Bosch process and O2 is returned to the atmosphere. Carbon builds up and fouls the catalyst at a rate of 1 kg per day. Finding useful ways to utilize the carbon produced in the Bosch process would be very beneficial. One area of particular interest is additive manufacturing. Additive manufacturing onboard ISS provides the ability to manufacture parts on demand allowing for critical replacement parts and tools to be manufactured without the need to wait for them to arrive. ABS filament is used on ISS for additive manufacturing, and although ABS is a relatively strong plastic, when ABS manufactured parts are used as tools there is a great chance of the manufactured parts to fracture. The addition of carbon to the ABS filament is likely to solve this issue.