The case for onboard carbon dioxide capture on long-range vehicles

https://news.northwestern.edu/stories/2021/08/the-case-for-onboard-carbon-dioxide-capture-on-long-range-vehicles/

"...shrinking the fuel chamber as the fuel is used, making space for CO2 in the other chamber."

Related: Elon Musk has big plans for turning this greenhouse gas into rocket fuel
https://web.archive.org/web/20211220222247/https://www.popularmechanics.com/space/rockets/a38569598/elon-musk-carbon-dioxide-rocket-fuel/