ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Unraveling the effects of calcination on the properties and CO₂ capture performance of Turkish coffee grounds

Gamze Özçakır

Department of Chemical Engineering, Faculty of Engineering, Bilecik Şeyh Edebali University, Bilecik, Turkey

E-mail: gamze.ozcakir@bilecik.edu.tr

Received: 26 March 2026  Accepted: 30 April 2026

Abstract:

In this paper, low-cost carbonaceous materials were obtained from Turkish coffee grounds by one-pot physical activation under an air atmosphere at 300 and 500 °C for CO₂ capture. The characterization of these adsorbents was conducted to investigate their structural properties. One of these adsorbents, which was calcined at 500 °C, exhibits an impressive CO₂ capturing performance (20.07 mmol/g) at ambient conditions (25 °C, 1 atm). The experimental data were found to be in complete correlation with the Freundlich isotherm model. Thermodynamic data proved that the reaction occurred spontaneously. Briefly, the results reveal that calcinated Turkish Coffee Grounds have high potential to adsorb the main greenhouse gas without utilizing any pretreatment with hazardous solvents and chemicals in their preparation. The success of this material was primarily based on its high surface area (2,534 m²/g), natural carbonate content, and layered structure.

Keywords: CO2 capture; Adsorption; Biomass ash; Air activation; Biomass characterization

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04986-0

Chemical Papers 80 (8) 9779–9790 (2026)