Development of plastic flatbed-based algal culture system deployable on non-arable land

Abstract

The industrial use of microalgae as bulk commodities relies on large scale and economical production. We recently reported a flat, open and shallow (FOS) culture method. In the present study, microalgae (Chlorella sorokiniana) were cultivated in various modes to evaluate key parameters and assess biomass and productivity. Using batch mode with 1-5 cm culture depth, the highest volumetric and areal productivity were 0.37 g L−1 d−1 and 9.08 g m−2 d−1, respectively. Using fed-batch mode, the microalgae density reached 6.40 g L−1. The yield remained stable after the microalgae were harvested 11 times in the semi-continuous mode. The system was then upgraded and scaled up to 4000 L for outdoor experiments in autumn, spring and summer, and the productivities were 6.80, 7.20 and 7.60 g m−2 d−1, respectively. Technoeconomic analysis showed that compared with open pond systems, this method is more efficient in terms of investment, water, electricity and operation, thus having great potential for deployment on non-arable land for massive algal production.