Baltic Sea microalgae transform cement flue gas into valuable biomass

Abstract

We show high feasibility of using cement industrial flue gas as CO 2 source for microalgal cultivation. The toxicity of cement flue gas (12-15% CO 2 ) on algal biomass production and composition (lipids, proteins, carbohydrates) was tested using monocultures (Tetraselmis sp., green algae, Skeletonema marinoi, diatom) and natural brackish communities. The performance of a natural microalgal community dominated by spring diatoms was compared to a highly productive diatom monoculture S. marinoi fed with flue gas or air-CO 2 mixture. Flue gas was not toxic to any of the microalgae tested. Instead we show high quality of microalgal biomass (lipids 20-30% DW, proteins 20-28% DW, carbohydrates 15-30% DW) and high production when cultivated with flue gas addition compared to CO 2 -air. Brackish Baltic Sea microalgal communities performed equally or better in terms of biomass quality and production than documented monocultures of diatom and green algae, often used in algal research and development. Hence, we conclude that microalgae should be included in biological solutions to transform waste into renewable resources in coastal waters.

Production stability and biomass quality in microalgal cultivation – Contribution of community dynamics

“…Euglenoids are common in nutrient rich and eutrophied waters and were highly competitive in the CO 2 treatment but considerably less so in the FG treatment where Euglenoids were replaced by green algae. Flue gas did affect negatively the biovolume of Euglenoids compared to CO 2 , although cement FG has been shown to be a suitable source of CO 2 for Baltic microalgae . The presence of an inhibitory compound in the cement FG that targets specifically Euglenoids cannot be dismissed.…”

“…Environmental fluctuations, contamination by pathogens and grazers often undermine industrial‐scale algae cultivation. Ongoing research, using fundamental ecological principles, particularly the stability and resilience of diverse microalgal communities, as a powerful approach toward the sustainability of industrial‐scale algal cultivation has received increasing attention . Moreover, industrial flue gas can be an inexpensive source of CO 2 used in the cultivation process .…”

“…However, Olofsson et al. demonstrated that cement flue gas was an appropriate CO 2 source for microalgae with the same or higher biomass production attained compared to industrial grade CO 2 .…”

Complex mathematical analysis of photobioreactor system

“…It should be highlighted that logistics, preparation, and use according to the regional particularities can be a differentiator (e.g., seawater, brackish, freshwater and wastewater, cheap nutrients and fertilizers, flue gas from local sources: power-plant, cement industry, ethanol mills, biogas upgrading etc.) [20,36,38,[92][93][94][95][96][97][98][99].…”

An informatics-based analysis of developments to date and prospects for the application of microalgae in the biological sequestration of industrial flue gas

“…Among these published papers, most of researches focused on CO 2 fixation and utilization for production of algal biomass and high-value products, suggesting the possibility of capturing CO 2 and using the obtained algal biomass for various industrial applications. For example, Olofsson et al obtained high quality of microalgal biomass (lipids 20-30 % DW, proteins 20-28 % DW, carbohydrates 15-30 % DW) and high production when cultivated with flue gas addition (Olofsson et al 2015), and Kumar et al investigated the feasibility of using Chlorella sorokiniana for CO 2 sequestration from industrial flue gas with an inlet CO 2 content of 4.1 % (v/v) (Kumar et al 2014); both showed high feasibility of using cement industrial flue gas as a CO 2 source for microalgal cultivation.…”