Work

Comparative analysis of non-isothermal decomposition kinetics in Chrysotila carterae (Haptophyta) culture: Effects of coccolith removal

Year: 2025

Type: article

Abstract: The cement industry is a major contributor to global CO 2 emissions, necessitating sustainable alternatives. Biocement production using microalgae-derived calcium carbonate (CaCO 3 ) offers a promising solution. Coccolithophores, a group of calcifying microalgae, naturally produce CaCO 3 , which can be extracted and utilized in biocement production to reduce the industry's carbon footprint. This study investigates the thermal degradation of Chrysotila carterae biomass before and after coccolith removal to assess its thermal stability. Thermogravimetric analysis (TGA) confirmed effective coccolith extraction via acid treatment. Isoconversional models (Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, and Starink) were applied at multiple heating rates (5, 10, 25 °C/min) to determine the activation energy (Ea). The coccolith-free biomass exhibited significantly higher Ea values (3441.2 ± 4.3 kJ/mol) than biomass with coccoliths (536.4 ± 4.8 kJ/mol), indicating improved heat resistance. Further kinetic modeling using Coats-Redfern and Malek methods identified the three-way transfer model as the best fit. These results provide crucial insights into the thermal behavior of C. carterae , facilitating its optimal use in biocement production. Additionally, understanding its thermal decomposition enhances the feasibility of utilizing the residual biomass in other applications, including bioenergy. This study contributes to advancing sustainable cement alternatives and biomass valorisation. • Coccolith removal increased activation energy from 536.4 to 3441.2 kJ/mol. • Acid treatment effectively removed coccoliths from Chrysotila carterae biomass. • FWO, KAS, and Starink models used at 5, 10, and 25 °C/min heating rates. • Three-way transfer model showed the best fit, with MSE of 0.005 • Coccolith removal enhanced thermal stability and biocement potential.

Source: Biomass and Bioenergy

DOI: 10.1016/j.biombioe.2025.107921

Authors: Saleha Al-Mardeai, Hilal El-Hassan, Navid R. Moheimani, Waleed Hamza, Tamer El-Maaddawy, Sulaiman Al-Zuhair

Institutions: United Arab Emirates University, Murdoch University

Language: English

Topic: Thermal and Kinetic Analysis

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Climate action, Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $4,270