Peter He, a professor in Auburn's Department of Chemical Engineering, is leading the $2.5 million US Department of Energy (DOE)-funded, project, “Intensified and Energy Efficient Cultivation, Processing, and Conversion of Flue Gas Produced Algal Biomass to Aquafeed.”
“We believe that we can reduce harmful wastes from both pulp and paper and aquaculture industries and turn them into something useful,” He said. “As the population increases, the demand for protein will increase. One means to produce protein is through aquaculture, which has the greatest overall efficiency compared to other animal production systems. To achieve a circular aquaculture, converting waste into aquafeed is very important.”
Bench scale prototype of the recently patented circulating coculture biofilm photoreactor (CCBP) developed at Auburn University. The technology proposed in this project, “dry” biofilm photobioreactor, is based on CCBP, which will be used as the platform for intensified microalgae cultivation from flue gas and fishery wastewater.
The project is part of a multi-university/industry DOE initiative aimed at advancing mixed algae developments for low-carbon biofuels and bioproducts. This aims to significantly enhance current algae cultivation technologies by increasing productivity by 200 percent, boosting biomass concentration by 300 percent, and reducing production costs by 50 percent. Besides directly capturing carbon dioxide from flue gas and converting it into algae, the utilisation of algae as aquafeed further boosts greenhouse gas emission reduction.
Success of this project, He said, relies on three key innovations:
- Using dry microalgae biofilm as biocatalysts to intensify the flue gas conversion process and improve biomass productivity.
- Adapting advanced and energy efficient pulp and paper dewatering and drying techniques for algae dewatering and drying.
- Systems engineering approaches that employ feedstock integration, logistic integration, process integration and energy/heat integration.
“Various studies have demonstrated that biofilm-based microalgae cultivation has many advantages over raceway ponds and conventional photobioreactors,” He said. “One key innovation of our solution is the dry biofilm. By making biofilm dry, the transport of carbon dioxide to the biocatalyst will be significantly enhanced, therefore improving carbon dioxide uptake and biomass productivity.”
The project will divide specific tasks among the researchers.
He and Wang will optimise and quantitatively assess algae productivity in a 104-litre lab-scale dry biofilm photoreactor using flue gas and aquaculture wastewater. This is expected to fine-tune the technology and optimise the operation parameters.
Researchers will move to a greenhouse-style 1,000-litre prototype, to be developed by DVO, for pilot testing at the Auburn University Fisheries.
Jiang, who also directs the Alabama Center for Paper and Bioresource Engineering, will test, optimise and compare different dewatering techniques on microalgae in his laboratory to significantly improve algae harvesting in economic and sustainability metrics.
Davis' lab will oversee the evaluation of the aquafeed ingredients’ nutrient profile, safety and efficacy for potential commercial aquafeed applications.
