The present study was formulated to assess microalgae productivity potential in hypothetical commercial scale flat panel photobioreactors in different locations in the United States, taking into account geospatial variabilities. Furthermore, the quantitative model was coupled with a detailed economic analysis to determine microalgae production costs for the different locations studied. Microalgae-based biorefinery, being at the nascent stage of commercial development, are often characterized by uncertainties and associated economic risks. In order to minimize uncertainties and associated risks and to ensure its commercial success, comprehensive understanding of microalgae growth and harvesting and the influence of process parameters on microalgae growth are critical. Thus, the first principles based microalgae growth model developed in the study is a significant step forward in predicting algae productivity for a given geographic location. Such a comprehensive approach helped to provide more realistic annual algae productivity potential, by incorporating local climatic factors for a given location. The economic analysis in the study quantified the total capital and operating costs of microalgae cultivation in flat panel photobioreactors operated in a commercial scale. Correspondingly, the minimum microalgae selling price for each location was determined based on the capital and operating expenditures. A sensitivity analysis helped to quantify the impacts of biological and process engineering parameters on microalgae production costs. The present techno-economic analysis of microalgae production confirms that microalgae-based technologies have significant potential for the production of food, feed, pharmaceuticals and nutraceuticals. However, there exists several challenges for commercial scale algae cultivation including availability of raw materials and nutrients as well as land and water resources availability. Ongoing research work on microalgae is thus essential to provide technological breakthroughs to address the challenges posed by commercial scale algae cultivation. Thus, with further microalgae research and development, it will certainly be possible to develop and implement economically feasible and environmentally sustainable approaches to algae cultivation and utilization and help achieve a sustainable bioeconomy.
The funding support from the Buckman Graduate Fellowship and from the Department of Bioproducts and Biosystems Engineering at the University of Minnesota is greatly appreciated.
Conflict of interest
The authors declare no conflict of interest.