Our project aims to facilitate society's integration back into normal life by equipping indoor workspaces with the ability to provide clean, fresh, pathogen-free air in these spaces. It does so by taking air from outside and:
But Olympus doesn't stop there. Taking further inspiration from the Environment Control and Life Support Systems (ECLSS) in the ISS we decided integrate a carbon dioxide recycling system [3]. Air coming in from the outside as well as the indoor air are passed through a molecular sieve made of a nano-porous material called "zeolite" which is highly effective at capturing CO2 [4]. Having several zeolite sieves allows one to be lowered down into a hot chamber below once it has been saturated with CO2, where a reaction called the "Bosch" reaction [5] is exploited to turn CO2 and hydrogen gas into water and solid carbon in the presence of a catalyst, in this case iron rods. The hot steam is then used to run a turbine which turns the fan that takes the outside air in to be initially filtered.
The steam is then condensed into water and through electrolysis it is split into oxygen and hydrogen. The oxygen is vented to the main airflow going in the building, while the hydrogen is pumped in the Bosch reaction chamber, thus closing the loop of CO2 recycling.
As many countries in the world start to lift their lockdown restrictions to prevent further damage to their economies and people start to go back to their day-to-day lives, many are still scared and uncertain about their health and safety. What is especially concerning is a second wave of infections emerging, which would pose even more catastrophic consequences for everyone in the world.
After living in the United Kingdom during the COVID-19 pandemic, a country whose population suffered a lot from the spread of the virus (currently with 250,000 confirmed cases and 38,000 casualties [6]) , it was hard to accept for friends and loved ones that they would have to go back to their normal lives with the uncertainty and fear of a second wave of infections. Having an engineering background, our team was inspired to make a difference and alleviate the consequences that might come from the re-opening of the economy by introducing Project Olympus.
We approached the project with the idea of integrating current space technologies used aboard the ISS to maintain the required air quality for the station crew into existing air filtration systems used on Earth in order to improve the indoor air quality as well as help in reducing CO2 concentrations in the outdoor air around Olympus itself.
Many research papers and technology reports provided by NASA and other online sources were used in order to come up with a system which would prove to be a working solution. Technologies such as the silica and HEPA air filters were looked into to determine their effectiveness on capturing moisture and harmful airborne particles respectively [7], while technologies such as the Photo Catalyst filter were inspired by current projects aboard the ISS like the Advanced AstrocultureTM (ADVASC) [8] . The use of zeolite molecular sieves was also inspired by their use as CO2 scrubbers in the ISS as part of the Carbon Dioxide Removal System (CDRS) and their high temperature stability (since they need to be lowered in the Bosch reactor where the temperatures will be 450 - 600 degrees Celsius) was also confirmed to be more than adequate [9].
In order to present our solution, our team used Computer Aided Design (CAD) software, most notably SolidWorks and Rhino, to come up with a presentable physical desgin.
The most notable achievement of project Olympus is not only the ability to provide clean air for people returning to workplaces after a long period of lockdown, but also the self-sustaining CO2 recycling loop, which only requires a small amount of water and electricity to initially be kickstarted, and makes the filtering process run by spinning the fan that takes in the outside air to be filtered in the first place. Not only that, but now the air is being cleaned off of a recently very abundant greenhouse gas like CO2, potentially contributing to the purification of the surrounding outdoor air.
Unfortunately, some problems with the current design have been identified. Firstly, the carbon produced in the Bosch reaction chamber will poison the iron catalyst rods by falling on the surface and reducing the surface area available for reaction to occur [10]. Our team suggests a scraping method by which the iron rods are lowered down and the carbon is scraped off, but that would pose other issues mechanically and in maintaining the required gas pressure in the chamber.
Another problem can be the production of oxygen during electrolysis. This can be highly combustible, and thus a lot of caution must be exercised so no leaks are present or that the temperature near the electrolysis setup does not get too high.
PDF link of slideshow (videos are images):
https://drive.google.com/file/d/1tAwQzBHnrj0_6-_RA-3vEUjEQT6l50G1/view?usp=sharing
Slide Show link (videos should work):
https://ispri.ng/qnQRg
[1] DOE Technical Standard. Specification for HEPA Filters Used by DOE Contractors. U.S Department of Energy, Washington D.C. 20585. https://www.standards.doe.gov/standards-documents/3000/3020-astd-2015/@@images/file. Accessed 31 May 2020.
[2] NASA - Air Purification. https://www.nasa.gov/mission_pages/station/research/advasc.html. Accessed 31 May 2020.
[3] NASA. Closing the Loop: Recycling Water and Air in Space. https://www.nasa.gov/pdf/146558main_RecyclingEDA(final)%204_10_06.pdf. Accessed 31 May 2020.
[4] National Space Society. Carbon Dioxide Control: Molecular Sieves. https://space.nss.org/settlement/nasa/teacher/course/zeolite.html. Accessed 31 May 2020.
[5] Holmes, R.F et al, 1970. A carbon dioxide reduction unit using Bosch reaction and expandable catalyst cartridges. San Diego, CA.
[6] Coronavirus (COVID-19). Google News, https://news.google.com/covid19/map?hl=en-US&gl=US&ceid=US:en. Accessed 31 May 2020.
[7] A. Joubert, J. C. Laborde, L. Bouilloux, S. Callé-Chazelet & D. Thomas. 2010. Influence of Humidity on Clogging of Flat and Pleated HEPA Filters, Aerosol Science and Technology, 44:12, 1065-1076, DOI: 10.1080/02786826.2010.510154
[8] NASA. Advanced Astroculture (ADVASC).https://www.nasa.gov/centers/marshall/news/background/facts/advasc.html. Accessed 31 May 2020.
[9] Musyoka, N.M., Petrik, L.F., Hums, E. et al, 2015.Thermal stability studies of zeolites A and X synthesized from South African coal fly ash. Res Chem Intermed 41, 575–582. https://doi.org/10.1007/s11164-013-1211-3
[10] Howard. D, NASA. Bosch Reactor Development for High Percentage Oxygen Recovery From Carbon Dioxide. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160008027.pdf. Accessed 31 May 2020.