How Do Different Chemicals Affect What a Hydrogen Generator Produces?

Hydrogen gas is generated by various chemical processes for industrial purposes, and, increasingly, for use in clean energy applications. The generation of hydrogen gas by any chemical process produces by-products that are specific to the process.

Steam Reforming

The principal method of hydrogen gas production is steam reforming of fossil fuels, especially methane gas. At high temperatures, methane (CH4) reacts with steam in the presence of a metallic catalyst to produce hydrogen gas (H2) and carbon monoxide gas (CO), by the reaction: CH4 + H2O = CO + 3H2.

The Kvaerner Process

The venerable Kvaerner process produces hydrogen gas from natural hydrocarbon fuels. In a high-temperature plasma burner, the hydrocarbons are reduced to their essential components, carbon (C) and hydrogen gas, by the general reaction: CnHm + heat = nC +m/2 H2.

For example, methane is reduced as follows: CH4 + heat = C + 2H2.

Coal Gasification

Coal gasification is a process that produces coal gas, a mixture of carbon monoxide and hydrogen gases, from reaction of coal (essentially carbon) and oxygen (O2): 3C + O2 + H2O = H2 + 3CO.

This reaction is followed by the "shift reaction": CO + H2O = CO2 + H2. The CO2 is stored underground, and the hydrogen is used to power electricity-generating turbines.

References

• International Journal of Molecular Sciences: High Temperature Metal Hydrides as Heat Storage Materials for Solar and Related Applications
• Hydrogen Fuel Cars Now: Hydrogen Generator Types
• Environment360: The Myth of Clean Coal

Resources

• Basic Research Needs for the Hydrogen Economy: Report, May 2003