As nonrenewable fuel supplies dwindle and pollution becomes a greater challenge, the search is on for viable, renewable sources of energy. Some of the more promising areas of research and development include the use of hydrogen, solar and wind power, and even nuclear energy. Chemical engineers have a unique grounding in chemistry, physics, and math. By virtue of this diverse training they are particularly well suited to the task of discovering and exploiting the many opportunities available in this array of alternative energy sources.
Today use of hydrogen as a fuel has inherent limitations. It is costly to produce and difficult to store and distribute to households and gas stations. Chemical engineers are in the forefront of the race to develop viable processes to produce safe, economical sources of hydrogen and to deliver it where needed.
Making Hydrogen Work
Although hydrogen is a cleaner alternative to fossil fuels, its use as a fuel presents several obstacles that must be overcome. It is difficult to store and distribute. No method currently exists for delivering hydrogen to households, and no infrastructure is in place to allow fuel cell-powered cars to refuel at local gas stations. Chemical engineers are heavily involved in the development of a variety of safe and technically feasible systems to produce hydrogen cost efficiently on a small scale.
- Low-pressure and low-temperature fuel processors able to produce hydrogen from hydrocarbon fuels;
- Use of coal-derived synthetic gas as a source of hydrogen;
- Extraction of hydrogen from fossil fuels; and
- An imaginative array of new processes based on
- Water splitting,
- Biomass and wastewater reforming, and
- Renewable electrolysis.
Hydrogen fuel cells
Efforts are under way to develop fuel-cell batteries that would use hydrogen or other fuels that can be converted to hydrogen. These mini power plants would produce electricity directly from hydrogen and oxygen, with the only discharge being water vapor. Because fuel cells rely on electrochemistry rather than combustion, they virtually eliminate the emission of pollutants associated with today's cars, trucks, buses, and power plants.
Solar and wind energy
The desire to harness the sun's energy is age old. However, it was not until 1939 that the first fully functioning solar-powered house was built at the Massachusetts Institute of Technology. Like solar energy, wind power is also environmentally friendly. In 2006 the total installed U.S. wind-based energy capacity could meet the annual electricity needs of 2.3 million homes.
Turning solar energy into electricity
Harnessing the sun's energy is an idea as old as humankind. Early civilizations routinely relied on the sun for heating and drying purposes. Methods evolved, and in 1939 Hoyt Hottel, a Massachusetts Institute of Technology professor, built the first fully functioning solar-energy house. Its practical flat-plate collector design has remained virtually unchanged and is still in use today.
As supplies of fossil fuel and cheap electricity have dwindled, methods to harness solar energy are in demand once again. Since chemical engineers are well trained in both material science and heat transfer, their efforts have been instrumental in designing the most efficient systems for collecting solar energy and converting it to electricity.
Capturing wind energy
Wind-based power generation is inherently environmentally friendly. However, wind is by nature unpredictable, and its strength and reliability are dependent on location. To cope with these variations, wind farms tend to install hundreds, or even thousands, of wind turbines. Still, rather than as a sole source of power, wind farms are most commonly used to produce electricity that is blended into the power grid.
Wind technology has progressed significantly over the past quarter century. While modern windmill designs are the domain of mechanical engineers, chemical engineers have been involved with the materials used, sensor and control systems, and such environmental issues as climate disruption.
Nuclear power plants create less air pollution than conventional power plants. But they do produce radioactive products that require long-term confinement storage. Advances spearheaded by chemical engineers have helped improve safety, increase power output, and maximize operating life.
Maximizing efficiency and safety
Despite ongoing political and environmental opposition, nuclear energy is expected to play an expanding role in our overall energy mix in the years to come. Nuclear energy generates much less greenhouse gas than does energy from fossil fuels.
Chemical engineers routinely work with nuclear engineers to design, develop, monitor, and operate nuclear power plants in the safest, most efficient manner possible. These scientists are also involved with the production, handling, use, and safe disposal of nuclear fuels.
Although few nuclear power plants have been built in the United States in recent decades, most existing plants have been modified to incorporate state-of-the-art advancements. Spearheaded by chemical engineers, these advancements have been developed to
- Improve safety,
- Increase power output, and
- Extend operating life.