Co2 sequestration experiments by producing geopolymer specimens from lignite fly ash

Kurusta, Tamás and Kitti, Patrícia Klaj and Teemu, Kinnarinen and Nazila, Bolourieh and Mucsi, Gábor (2025) Co2 sequestration experiments by producing geopolymer specimens from lignite fly ash. GEOSCIENCES AND ENGINEERING: A PUBLICATION OF THE UNIVERSITY OF MISKOLC, 13 (1). pp. 88-96. ISSN 2063-6997

Preview

Text 07_Kurusta.pdf - Published Version Download (498kB) | Preview

Abstract

The mineral-based sequestration of CO₂ offers a permanent and safe method to store CO₂ captured from flue gas. In this process, CO₂ reacts with calcium and/or magnesium-bearing materials to form stable, environmentally benign carbonate minerals. In a recent research project, CO₂ sequestration was performed on deposited fly ash from Visonta, Northern Hungary, coupled with mechanical activation. The resultant carbonate phases were analyzed for their suitability as geopolymer-based construction materials. CO₂ sequestration and mechanical activation occurred in a Fritsch Pulverisette 5 planetary ball mill under wet conditions. The samples were dried post-sequestration, and 20 × 20 × 20 mm geopolymer specimens were prepared and tested for compressive strength after seven days. It was found that bassanite, the primary calcium source in fly ash, reacts with CO₂ only in the presence of NaOH. Additionally, low NaOH concentrations (0.5 M) during grinding positively impacted the compressive strength of the geopolymer, while higher concentrations reduced it. At 2 M NaOH, the specimen failed to set fully, deforming plastically under pressure. The experiment yielded a maximum compressive strength of 16.1 MPa for the geopolymer using 0.5 M NaOH.

Actions (login required)

Edit Item