TITLE:
Novel Activated Carbon Monoliths for Methane Adsorption Obtained from Coffee Husks
AUTHORS:
Liliana Giraldo, Juan Carlos Moreno-Piraján
KEYWORDS:
Coffee Husk, Activated Carbon, Isotherm Adsorption, Carbon Monolith, Methane Adsorption, Isosteric Heat of Adsorption, SEM
JOURNAL NAME:
Materials Sciences and Applications,
Vol.2 No.5,
May
5,
2011
ABSTRACT: Methane adsorption by different forms of activated carbon obtained from coffee husks, including monolith honeycomb and disc types, was studied by activation with zinc salts and potassium hydroxide at 298.15 K and 303.15 K and pressures up to 30.00 atm in a volumetric adsorption apparatus. We observed increased methane adsorption capacity on a mass basis in the different activated carbon monoliths with increasing surface area, total pore volume and micropore volume, with the honeycomb type displaying the highest methane absorption capacity. The maximum volumetric methane uptake by the synthesised carbon monoliths was observed to be 130 V/V at 298.15 K and 30.00 atm for honeycomb monoliths synthesised with zinc chloride (ZnCl2) and Polyvinyl alcohol (PVA) as the binder. Adsorption calorimetry results were used to describe the interaction between guest molecules and the adsorbent at low surface coverage and the energetic heterogeneous surface nature of the adsorbent.