Engineers Without Borders Waterloo Team wins at OpenAir Carbon Removal Challenge

Anjiya Sharif, a fourth-year chemical engineering student, became a member of Engineers Without Borders in her first year at the University of Waterloo with the intention of practising engineering for social good.

Sharif is interested in CO₂ capture and during one of her co-op terms had been in the research sector learning about it. During this time, she attended workshops run by the OpenAir Collective which was introduced to the University of Waterloo by Engineers Without Borders in 2022. In 2023 Sharif was part of a team of twelve undergraduate engineers who went to New York City to take part in the first-ever OpenAir Carbon Removal Challenge.

The Waterloo team, working under the supervision of Dr. Xiao Yu Wu, designed and built a prototype that can remove CO₂ directly from the air. It uses that captured CO₂ to grow algae in just under four months. The CO₂ capture process is driven by a moisture swing. CO₂ is captured under dry conditions and released under wet conditions.

The prototype works in a novel way. A fan blows air onto an ion-exchange resin called AmberLite which has a molecular structure that can bind to and pull a very small quantity of CO₂ from the air. Water is then pumped into a resin. Once the resin becomes saturated with CO₂, it needs to be released and so it is primed for re-use. Water molecules can replace the CO₂ molecules at the AmberLite binding sites. After this ion swap, AmberLite is ready to capture more CO₂.

CO₂-enriched water is pumped into a beaker of algae. A strain of single-celled algae called Chlorella Vulgaris is used because it’s shown to have a faster growth rate when exposed to more CO₂. It’s also edible! Sharif’s background in Chemical Engineering influenced her participation in the project.

“Chemical Engineering course and lab work helped significantly during the prototype design process. The AmberLite resin was arranged in a fluidized bed configuration, the background knowledge for which was learned in CHE 314 (Chemical Reaction Engineering) and the implementation for which was practiced in the CHE 390 (Chemical Engineering lab 3) project design lab,” says Sharif. “The force balances used in the project lab helped us calculate the air and water flow rates required for fluidizing the AmberLite resin. This helped us size our pumps.”

The Waterloo Team was one of the five finalists in the OpenAir Carbon Removal Challenge. The showcase ended with a pitch presentation that was broadcast globally, and during this event, the categorical wins were revealed. The Waterloo team emerged victorious in the category of "Most Detailed Design"!

 The team has already begun preparing for next year’s competition with two key changes to their design. They will be using a different, more accessible ion-exchange resin for the capture component. This would be a completely novel use of a molecule with an established supply chain. Instead of utilizing CO₂ for algae growth, they will be experimenting with bacteria to transform CO₂ into a valuable bioplastic.  

The University of Waterloo Engineers Without Borders chapter is looking for new members. If you are interested, please join EWB slack!