Methane Adsorption on Carbonaceous Microporous Materials Prepared from Cellulose and Lignin: Equilibrium and Kinetic Studies

Document Type: Article

Authors

1 Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran

2 Sharif University of Technology

3 Gas Division, Research Institute of Petroleum Industry, Tehran, Iran

Abstract

The present investigation highlighted the methane adsorption on synthesized activated carbons (ACs) based upon hydrothermally treated cellulose and lignin followed by a chemical activation utilizing the ZnCl‌2 as an activating agent. The influence of effective parameters such as; hydrothermal pretreatment, precursor type, carbonization temperature, and impregnation ratio upon the textural properties of synthesized materials as well as adsorption capacities of methane examined. Thermal stability and decomposition procedures of cellulose and lignin determined through the TGA technique while all prepared ACs characterized via the N2 adsorption-desorption analysis utilizing the BET-BJH surface area measurement and field emission scanning electron microscopy (FESEM). FTIR spectra of the prepared species were obtained in order to investigate the existing functional groups and consider effects of the added activating agent upon them. Amongst all prepared materials, the AC produced through hydrothermally treated cellulose impregnated with ZnCl‌2 possessing a ratio of 1 and carbonized at 600˚C revealed improved surface and textural properties enhancing the methane storage. Furthermore, hydrothermal pretreatment provided micropore diameters ranging from 1.8-2.2nm. These resulted in 6.42mmol/g of methane adsorbed at 298K and 3.65MPa. In order to systematically understand behaviors of adsorbents for the process at hand several kinetic and isotherm models understudied.

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