A comparative study on methane adsorption onto various adsorbents including activated carbons, zeolites, MWCNT, and MCM-41

ABSTRACT

In this study, it was aimed to produce low-cost activated carbons from cornelian cherry stones (CCS) by ultrasound-assisted chemical activation with the use of LiOH, KOH, NaOH, and ZnCl₂. In the study, adsorption capacities of the activated carbon samples for CH₄ compared with that of commercially obtained activated carbon (AC), multi-walled carbon nanotubes (MWCNT), mesoporous silica (MCM-41), and various zeolites. BET and t-plot analysis have been used for the characterization of adsorbents with the use of N₂ adsorption-desorption data and SEM. In the evaluation of the adsorption data, several isotherm models such as DR, Harkins-Jura, Temkin, Freundlich, and Langmuir have been used. It was observed that activated carbons showed higher CH₄ adsorption capacity than commercial mesoporous adsorbents and microporous zeolites. The CH₄ adsorption capacity of commercial activated carbon was measured to be 0.939 mmol/g, while the CH₄ adsorption capacities of activated carbons obtained with the use of NaOH, KOH, LiOH, and ZnCl₂ were found to be 2.455, 1.584, 1.477, and 1.433 mmol/g, respectively. Results showed that activated carbons obtained from CCS with the use of KOH, NaOH, LiOH, and ZnCl₂ are effective low-cost adsorbents for CH₄ adsorption.

KEYWORDS:

• CH₄ adsorption
• cornelian cherry stones
• ultrasound-assisted impregnation
• activated carbon
• zeolite

Acknowledgments

This work was supported financially by Kocaeli University, Turkey (Kocaeli University Scientific Research Project 2017/57 HD).

Additional information

Funding

This work was supported by the Kocaeli Üniversitesi [Scientific Research Project 2017/57 HD].