Activated petroleum coke for natural gas storage

Abstract

Activated Carbons (AC) are characterized by high specific surface area and high pore volume. They are mostly produced by activation of high carbon content precursors, for example petroleum coke (PC). In the present work samples of PC were chemically activated with potassium hydroxide (KOH). The activated PC presented high capacities of N2 adsorption at 77 K, with pore volumes up to 1.5 cm3 g-1 and specific surface area up to 2500 m2 g-1. The pore size distributions obtained indicate that the activated PC has pore sizes concentrated in the supermicroporous range (diameters between 0.7 nm and 2 nm). The temperature and the impregnation ratio used in the activation process were the variables that mostly affected the porosity of the activated PC. The storage capacity of the activated PC, obtained by methane adsorption at high pressure, was 91 v/v (methane volume stored by bed volume). ©2006 Sociedade Brasileira de Química.