Innovating for a Greener Brew: A Testament to Resilience

The world of brewing, although boasting a long-standing tradition spanning centuries, has been found to be a significant contributor to carbon emissions. Recognizing this environmental impact, the BioBrew senior design team set an ambitious goal: to revolutionize how breweries manage their carbon footprint. 

BioBrew is composed of five students:  Emmy van Witzenburg, an integrated engineering senior in the program's sustainability concentration, alongside four mechanical engineering seniors, Derrek Hissong, Joseph Marcinek, Christian Perez and Gabrielle Ramseier. The team's goal was to design and build a system that integrates the electrodialysis bipolar membrane designed by Ameridia Innovative Solutions for the capture of the CO2 generated during fermentation. 

The system designed by BioBrew separates CO2 from the gas stream that is produced during fermentation for the production of beer, and moves it under pressure to be stored in tanks. The stored CO2, in turn, can be made available to the brewery for reuse, thereby reducing the brewery’s carbon footprint and enhancing sustainability.

Initially, the team was sponsored by industry partner Carbon Blade, a company focused on the approach of distributed direct capture of CO2 from air. During the first semester, the team was tasked with designing a system for craft breweries to capture CO2 emissions and repurpose them for future use by the breweries. However, a change in leadership at Carbon Blade coupled with a re-evaluation of the scope of the project led to a pivot to smaller scale brewing applications.

Hissong notes: “This team wanted to continue something in the second semester that was good for the environment without wasting time from the work we put in last semester." This led them to downsize their focus to homebrewing operations — a strategic shift allowing them to develop a replicable system that, if proven effective on a smaller scale, could hold a potential for scalability to larger craft brewing operations.

The core of the BioBrew team’s homebrewing approach involves the use of algae for carbon capture. Ramseier articulates the problem statement: "The goal of this project is to demonstrate a sustainable method of reducing CO2 emissions generated during beer fermentation. We have developed a system that directs the CO2 concentrated off-gas from homebrewing fermentation into an algae sub-system, which absorbs CO2 via photosynthesis. This system has the potential for scalability to larger-scale craft brewing operations."

Perez and van Witzenburg made significant progress in proving the efficacy of their algae system. While initial plans to use CO2 sensors for precise quantification faced technical hurdles, they've adapted by using a sodium hydroxide scrubber to detect the presence of CO2 and measure volume. Their current goal, in consultation with faculty mentor Susan Lord, PhD, is to demonstrate a reduction in CO2 volume by approximately 40%.

The BioBrew project is a testament to collaborative and flexible innovation. The team has received support through a grant secured through faculty advisor Venkat Shastri, PhD, who acted as a sponsor for the project, with Assistant Professor of mechanical engineering Marissa Forbes serving the team as a valuable resource.

"The project with Carbon Blade was a part of a California Energy Commission grant to help the startup company develop a new product portfolio that can have a positive impact on the State’s Climate Action goals. While this was no longer possible due to changes in the company, we were able to redirect the team to a second application that would still be aligned with our original goals in the grant,” explains Ramseier. Shastri, who is the USD investigator on the grant, was able to “secure a $1,000 grant for our work in the spring.” 

Christian Perez (left) and Joseph Marcinek (right) at the 2025 Engineering and Computing Showcase

While Rasmeier and Hissong took on team lead responsibilities, Marcinek dedicated his time to CO2 sensor coding, Perez focused on quantifiable algae health and van Witzenburg was instrumental in brewing tests and "helped out with everything." This versatility has been crucial in navigating the challenges and successes of the project.

The BioBrew team exemplifies how innovative thinking and a commitment to sustainability can lead to impactful solutions, starting from a smaller scale with the potential to transform an entire industry.

“The students have demonstrated remarkable adaptability,” says Shastri, proud of the team’s resilience in the face of adversity. "It's not easy to pivot halfway through a senior design project, especially one with such an ambitious initial scope. But this group truly embodied resilience. They didn't just pivot; they did it seamlessly, adapting their vision and tackling new challenges with remarkable agility. Their ability to switch gears and maintain momentum without compromising the relevance of their project to the State’s Climate goals speaks volumes about their dedication to sustainability and their engineering ingenuity."

— By Michelle Sztupkay