Petroleum as Fuel for Fuel Cells (FCs)

Petroleum is made of gaseous, liquid, and solid hydrocarbon-based chemical compounds from sedimentary rock deposits around the planet. Crude petroleum, when refined, provides high-value liquid feeds, solvents, lubricants, and other products. Petroleum-based fuels make up almost one half of the energy supply in the world. Simple distillation is enough to make gasoline, diesel, aviation fuel and kerosene out of petroleum. How much is obtained, in terms of fractions, from the crude oil depends on the origin of the supply.

When fuel cells are considered, it is important to understand the physical and combustion characteristics of the fuel, as well as its chemical composition (it is this factor that determines the fuel processing type).

Different technologies have to be employed to convert the many fraction types of the petroleum into hydrogen for FCs. A special case is when the fuel is catalytically converted and generates various trace compounds that may be poisonous for the conversion catalysts and fuel cell stacks. In fossil fuels, the dominant trace compounds are of the organic type that contain sulphur, nitrogen or oxygen, and organo-metallic compounds (includes porphyrins).

Because the distribution of gasoline and diesel already has a well established infrastructure, there are good reasons for fuelling fuel cell vehicles (FCV) using a similar fuel. Studies, however, have shown that the efficiency of using gasoline in FCVs is nowhere near that of using pure hydrogen or even methanol. If such fuel is used in FCVs, it will most likely have a simpler chemical composition because there would be no need to add components for anti-knock or lubrication purposes.

Reference:

LARMINIE, James; DICKS, Andrew. Fuel Cell Systems Explained. 2. ed. West Sussex, England: Wiley & Sons Ltd., 2003. 418 p.

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