A comparative assessment of four analytical methods, i.e., thermogravimetric analysis, volumetric analysis, total/inorganic carbon analysis, and CHN elemental analysis to quantify the CO₂ equivalent carbon content in wood ash before and after lab-scale carbonation with pure CO₂ is provided with regard to the reliable quantification the CO₂ sequestration potential of wood ash.

Abstract

To assess mineral carbonation as a negative emission technology, the reliable quantification of the sequestered carbon is crucial. This study evaluates four methods for quantifying carbon sequestration by wood ash, through analyses of ash samples before and after lab-scale carbonation, and compares the results to the theoretical storage potential determined using the Steinour equation. Results show that CHN elemental analysis and total carbon quantification provided consistent values for total carbon content and for the amount of CO₂ sequestered. Inorganic carbon was effectively quantified using both total/inorganic carbon analysis (TC/IC) analysis and volumetric calcimetry. The findings highlight the importance of selecting analytical methods and demonstrate that oversimplified thermogravimetric analysis (TGA) can lead to misinterpretation of sequestration results.