Dynamic process model and economic analysis of microalgae cultivation in open raceway ponds

Microalgae are a promising biomass feedstock for production of value-added chemicals and bioproducts. A first principle based bioreaction kinetics and bioprocess model of microalgae production was developed for an outdoor open raceway pond that takes into account year-round geospatial characteristics and variability. The primary factors that affect microalgae growth, such as solar irradiance, temperature, biological growth parameters, nutrients and carbon dioxide uptake rates, were considered in the bioreactor process model. Microalgae productivity varied between 2000 and 7200 t km(-2) year(-1) for the different geographical regions studied. For each location, techno-economic analysis was conducted to assess microalgae production price. The capital and operating expenses for microalgae cultivation systems were quantified based on the mass and energy balances of the process. Given the geospatial locations, cost of microalgae production varied between 1074 $ t(-1) to 502 $ t(-1). Results showed that cost of microalgae production depends heavily on the average areal productivity, price of nutrients, as well as design specifications of microalgae growth ponds.