Project Title: Sub-Scale Thermally Coupled Temperature Swing Adsorption and Compression (TC-TSAC) System Redesign
William Leslie Fowler, mechanical engineering
Grace Marie Halferty, mechanical engineering
Briana Magdalena Otero, systems engineering
Joaquin Eduardo Pesquiera (project lead) electrical and computer engineering
Kenneth Werrell, mechanical engineering
Project Title: Sub-Scale Adsorption and Compression CO2 Removal System Redesign
Engineering seniors at the University of Arizona are building a system to help astronauts breathe in spacecraft environments, with the ultimate goal of making space exploration more sustainable.
CO2 scrubbers use material that adsorbs, or attracts and holds on its surface, carbon dioxide molecules – thus pulling them from the breathable atmosphere and making the air safe to breathe. Similar to a water purifier pitcher that requires replacement filters, the adsorptive material in these systems eventually fills up with carbon dioxide.
“The point of this project is to make a CO2 scrubber that can run virtually forever, because most of the current ones have material that does adsorbing until it’s saturated with CO2 and then needs to be replaced,” said Joaquin Pesquiera, an electrical and computer engineering student and project leader. “Ours will use a material that can release the CO2 and put it elsewhere.”
The team is completing a redesign of a Thermally Coupled Temperature Swing Adsorption Compressor (TC-TSAC) CO2 scrubber. In addition to using regenerable materials, the system combines what was traditionally two units: one part to pull, or scrub, CO2 from the air, and another to compress the air and send it downstream for conversion into useful products. For example, the CO2 may be reduced and combined with hydrogen molecules to produce water. Though such systems do exist, this team’s focus is on producing a more efficient and economical alternative.
They’re doing the project as part of the Moon to Mars eXploration Systems and Habitation (M2M X-Hab) 2022 Academic Innovation Challenge, sponsored by NASA’s Advance Exploration Systems division. The UA was among six universities from across the country selected to participate.
“My career goals are bioastronautics, which is basically space systems engineering – looking at how we can live in space,” said mechanical engineering major Grace Halferty. “It’s cool working on something that might have an impact in the future.”
The device will be sub-scale, capable of only a limited amount of CO2 removal, but the team is also modeling performance and scalability to remove up to 4 kg of CO2 per day. The average human breathes out about 1 kg in mass of carbon dioxide per day.
Space Analog for the Moon and Mars
To test the device, they’ll work with the University of Arizona’s Biosphere 2, the world’s largest controlled environment facility. Specifically, they’ll be testing it in the Space Analog for the Moon and Mars (SAM), a hermetically sealed habitat being constructed at the Biosphere 2. Analog environments like SAM are designed to mimic the way outer space settings can affect astronauts’ bodies and minds. These facilities, combined with the university’s history of partnerships with NASA, mean the team can do this research at the scale of a full human habitat.
“Students can take the new TC-TSAC system and test in a life-size controlled environment with analog astronauts,” said Trent Tresch, director of research and development for SAM and one of the team’s mentors. “They’re building a system from scratch and, in the end, potentially helping make the future of human space exploration more sustainable.”
The team has already reviewed existing literature and completed the first prototype, and they continue to hold meetings with NASA and SAM team members across several time zones. The students will operate the device in SAM while a known amount of CO2 is introduced into the space. They’ll measure the amount of CO2 present in the space before, during and after the test. Then, they plan to safely replicate the test with humans in the facility to accommodate for how breathing affects CO2 levels.
“In many ways, we’re in a unique position here at the UA, because we have the Biosphere 2, and we have local space companies like Paragon Space Corporation, which has sponsored capstone projects in the past. Another advantage is that last year, one of our capstone teams worked on a Biosphere 2 project to build a pressure regulating system for SAM, a Mars habitat analog, which is relevant to this year’s project,” said Ara Arabyan, former director of the Interdisciplinary Capstone program, who spearheaded the X-Hab application. “So, a lot of things combined to put us in a competitive position relative to other X-Hab applicants.”
Tresch said the students are making good use of the resources provided by the university, Biosphere 2 and NASA.
“Being a student during the new space age is such an exciting opportunity,” he said. “Students such as the UA crew have the chance to develop technology which will be directly and indirectly responsible for humanity expanding towards the stars.”