US Patent 7309381 Gas storage canister

A vapor storage canister used to treat fuel vapor of an automotive internal combustion engine. The vapor storage canister includes a casing. A granular formed heat accumulative material is disposed in the casing and includes a powdered heat accumulative agent formed of micro-capsules each of which contains a phase changing material which makes adsorption and release of latent heat in accordance with a temperature change. The granular formed heat accumulative material further includes a binder for binding the heat accumulative agents. Additionally, a granular gas adsorbing material disposed in the casing and mixed with the heat accumulative material.