Microalgae: Potential precursors of CO2 adsorbents. (July 2018)

• Record Type: Journal Article
• Authors: Durán, I.; Rubiera, F.; Pevida, C.
• Is Part Of: Journal of CO₂ utilization. Volume 26(2018)
• Page Start: 454
• Page End: 464
• Publication Date: 2018-07
• Subjects: Biomass -- Microalgae -- Adsorbents -- Activated carbon -- CO2 capture; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2018.06.001
• Languages: English
• ISSNs: 2212-9820

Abstract

Highlights: Four microalgae species, freeze-dried and/or pastes, were evaluated as precursors of CO2 adsorbents. Pre-treatment by hydrothermal carbonization did not improve CO2 adsorption capacity. Adsorbents produced from mixtures microalgae-pine sawdust showed enhanced density and CO2 uptake. Maximum CO2 uptake of 4 wt.% (0.9 mmol CO2 /g) at 50 °C and 10.5 kPa of CO2 . Abstract: With faster growth rates and higher photosynthetic efficiencies than other terrestrial plants, microalgae biomass could be considered as a green, low-cost, alternative carbon source. This paper explores the potential use of various species of microalgae as activated carbon precursors. C hlorella and Spirulina were evaluated both as freeze-dried microalgae and in fresh paste form, while Acutodesmus Obliquus and Coelastrella sp . were studied only as paste. Activated carbons were produced using the selected species of microalgae as well as mixtures of pine sawdust and microalgae. Two different preparation routes were compared: with and without hydrothermal carbonization pretreatment before physical activation with CO2 in a single step. All samples were conformed into pellets prior to CO2 activation. The CO2 adsorption capacity of the microalgae derived carbons was assessed in conditions representative of a flue gas (10.5 vol.% CO2 at atmospheric pressure and 50 °C). Significant differences in terms of CO2 adsorption capacity, carbon yield and pellet density were obtained among the species studied. These preliminary results showed that activated carbons produced from microalgae mixed with pine sawdust and directly activated with CO2 are among the most promising adsorbents to capture CO2 from flue gas.