Lindsey Shay Smith {EIT}

At Clemson University, every student is required to complete a Capstone project their senior year before they can graduate. In Biosystems Engineering, the requirements are to design a system or process that is relatable to our field. The design project is a group effort, and my group designed a biological reactor to grow algae using beer fermentation waste containing dead yeast cells and ethanol. This bioreactor features a two-step process in which the media will be prepared, then a pure culture of Chlorella protothecoides will be added and allowed to grow in a continuous stirred-tank reactor. The design allows algae to be grown heterotrophically and aerobically, using only the fermentation waste as a nutrient source. Once growth is complete, the algae can be harvested and used for biodiesels, biopharmaceuticals or to replace other petroleum-based products. A heat exchanger was also designed to keep the culture at the optimal temperature for algae growth.

 

This project has a focus on sustainability, the recycling of waste products and the creation of as little waste as possible. The worldwide issue of diminishing natural resources can be remedied by sustainable practices and the use of biodiesels such as the ones addressed by this design. If implemented at a brewery, this design could not only create another profit stream but would also allow for the brewery to eliminate a waste stream entirely and provide energy for their own processes.