The effects of particle size distribution on density of activated carbon [abstract]

Abstract

Methane is one of many alternative fuels that have been explored over the past few years in an effort to reduce our dependency on fossil fuels. Currently, methane can be condensed and used as a fuel for most large vehicles. The tank which contains the condensed methane typically is a bulky cylinder large enough to accommodate 3,600 pounds per square inch to store sufficient methane in the limited space on the vehicle. In an effort to make the tank more conformable to spaces available on a vehicle, a carbon adsorbent was developed that allows the use of lower pressures and “conformable” tanks. Adsorbed natural gas, or ANG, allows the methane to be stored at a lower pressure by utilizing the equivalent of a sponge to “soak up” the gas. Afterwards, the methane is released slowly from the sponge and can be burned in a combustion engine. Through extensive research, activated carbon has been found to be a good adsorber of methane and can be made from something as simple as corn cobs. “Activated” carbon has been made nanoporous with the use of a base such as KOH. Included is the study of particle size distribution and how it relates to the powder density and briquette density of the activated carbon. Taking different briquettes of carbon made from different average particle sizes, we tested the densities to find a correlation between particle size and briquette density. Results show that as particle size decreases, density increases and methane adsorption increases. This suggests that the higher density briquettes have more carbon to store condensed methane in the same volume than less density briquettes. With such findings, we are able to maximize the amount of methane adsorbed by maximizing the amount of carbon and thusly increase the marketability and utility of the ANG tank