Hydrogen Energy: Principles and Applications

Abstract Description: The current human population on Earth is approximately seven billion, and it will certainly increase in the future. The influence and effects of human activities on energy use have become increasingly evident at the local, state, national, and international levels. Particular interest in hydrogen energy has recently surfaced and the net result is that there has been a more significant increase in both awareness and analysis of hydrogen energy options since the turn of this decade.

Hydrogen may well emerge as a very important fuel by the middle of this century. However, since hydrogen is not a basic energy resource except in the sun, water or other hydrogen-containing chemical compounds, e.g., methane, ammonia, etc., are required to generate hydrogen. Once generated, hydrogen is an ecologically friendly fuel that is presently used in the propulsion of spacecraft and can potentially be mass-produced and commercialized for passenger vehicles and aircraft.

Hydrogen could play a major role as a carbon-free fuel in the future and is poised to become a major future energy supply/carrier (not an energy source), but here is the challenge. If employed as an alternative to fossil fuel, hydrogen should be:

1. Technically feasible and reliable from a process standpoint.
2. Economically attractive.
3. Easily converted to another energy form.
4. Of minimal or manageable safety and environmental concerns.

Here is the current thinking about hydrogen energy. Create it from hydrogen-bearing compounds with processes using water, fossil fuels, biomass, or waste as feed materials. Then store this hydrogen for as long as needed before converting it into electricity or energy in the form of heat or other useful end products.

This paper addresses the following hydrogen topics: availability/distribution, extraction/purification, transportation/transmission, energy-environmental interactions, storage, and uses. Three illustrative examples adopted from the authors’ 2025 hydrogen text complement this presentation.