High surface area and high pore volume activated carbon was prepared by KOH activation of rice hull and a series of monolithic forms of the activated carbon were prepared to increase packing density and energy density of adsorbed methane gas per volume for natural gas storage. The effect of process variables such as heat-treatment condition, binder content, and binder type on the pore structure, packing density and methane adsorption was investigated. The surface areas of the monolithic forms prepared with the mixture of phenol and a water-soluble polymer increased from 173-575 m(2)/ml to 451-678 m(2)/ml by the heat treatment. In the case of monolithic forms prepared with the mixture of water-soluble polymers, the surface areas were about twice of those with the mixture of phenol and a water-soluble polymer, while their packing density was in the similar range. The monolithic forms with the mixture of PVP/PVA have high packing density of 0.47 g/ml and high surface area of 2,150 m(2)/g(1,011 m(2)/ml), resulting in high energy density of adsorbed methane gas per volume of 124 v/v.