Industrial CO2 capturing by mass cultivation of microalgae (diatoms): Processes, sustainability and applications

Abstract

In the 2012–2013 academic year, a research group at UiT The Arctic University of Norway, with expertise in the physiology and ecology of planktonic microalgae, took on the challenge to test industrial mass cultivation of certain species of microalgae. This ambition was driven by the increasing focus on photoautotrophic (photosynthetic) microalgae as future biofuels, as well as a source of feed and food (Demirbas, 2009; Ratha & Prasanna, 2012). However, mass cultivation of microalgae at high concentrations demands a carbon (CO2) source at concentrations far above natural levels in the air or sea. At the same time, the ferrosilicon factory Finnfjord AS (which releases 300,000 tonne of CO2 and 1000 tonne NO x factory fume/year) was actively seeking more sustainable production processes. In this context, carbon capture and storage (CCS) was, for obvious practical reasons, not considered a viable alternative; but practising carbon capture and use (CCU) by sequestering CO2 with microalgae from the fume – and, at the same time, performing biosynthesis of nutritious biomass – seemed attractive and possibly economically sustainable.