Carbon dioxide and methane adsorption behaviour of zeolite/biomass-based activated carbon and zeolite/multiwalled carbon nanotube composites

Abstract

ABSTRACT In the present study, it was aimed to develop novel-activated carbon/zeolite and carbon nanotube/zeolite composites for CO2 and CH4 adsorption. The study consists of two parts; in the first part of the study, activated carbon has been obtained from elaeagnus stones and zeolite/activated carbon composites have been prepared from the activated carbon and commercial zeolite with the use of K2CO3 at different temperatures. In order to make comparisons, zeolite/multiwalled carbon nanotube composites have been prepared by using commercial-multiwalled carbon nanotube by the same method. All the composites have been characterised by N2 adsorption – desorption, Barrett-Joyner-Halenda (BJH) desorption pore size distributions and SEM-EDX techniques. In the second part of the study, CO2 and CH4 adsorption processes have been performed for obtained composites at room temperature and 760 mmHg pressure. The relationship between CO2 and CH4 adsorption capacities, Brunauer-Emmett-Teller (BET) surface areas and pore volumes of zeolite/activated carbon and zeolite/multiwalled carbon nanotube (MWCNT) composites have been investigated. Freundlich, Langmuir, BET, Temkin, Dubinin–Radushkevich (DR) and Harkins – Jura (HJ) isotherms have been plotted and the isotherm parameters have been calculated. It was observed that the CO2 and CH4 adsorption capacities of the zeolite/activated carbon composites are higher than the adsorption capacities of both zeolite and activated carbon. It was also observed that the zeolite/MWCNT composite ZN700 showed higher CO2 and CH4 adsorption capacity than both zeolite and nanotube. Results showed that the zeolite/activated carbon and zeolite/multiwalled carbon nanotube composites which were obtained with the use of K2CO3 are promising adsorbents for CO2 and CH4 adsorption for industrial use.