Finding solutions in an energy-constrained world
From the gasoline that propels our vehicles to the natural gas that warms our homes, fossil fuels provide the world with about 85% of its energy needs. When we turn the ignition key or crank up the thermostat, the burning of these fuels, a process known as combustion, releases their stored energy. Alongside the release of energy, however, come undesirable products like pollutants and CO2.
Finding ways to enhance the efficiency of combustion can help promote energy security, prevent environmental degradation and slow the process of climate change. The discovery of new ways to harness existing energy sources and develop new ones is an essential priority in the nation’s goal of energy independence.
Researchers at the Combustion Energy Frontier Research Center (CEFRC) are addressing that priority through efforts to enhance combustion efficiency, reduce emissions, explore carbon-neutral fuels and contribute to the formulation of fundamentally new fuels and engines. Funded by the U.S. Department of Energy, Basic Energy Sciences (DOE-BES) and headquartered at Princeton University, the CEFRC supports 14 principal investigators from seven academic institutions and two national laboratories.
Through a better understanding of combustion and fuel science, CEFRC researchers hope to:
- Develop fuels with fundamentally new properties by manipulating materials at the molecular level to optimize their behavior,
- Formulate novel ways to characterize or model the properties of fuel molecules, and
- Take control of the combustion process to produce clean and efficient energy using new engine technologies.
CEFRC researchers aim to accomplish the above goals by studying the combustion characteristics of three major classes of fuels: foundation fuels, alcohol fuels and biodiesel. Foundation fuels include hydrogen and small hydrocarbons such as methane and butane, which not only are fuels themselves but are also the foundational components of the more complex and larger fuel molecules. Alcohols are fuels that burn more cleanly than petroleum and can be produced from biomass. One of these alcohols is butanol which, when compared to commercially available ethanol, has a higher energy content and can be produced from a greater variety of biological sources. The third major class of fuel, biodiesel, can also be produced from many biological sources including plants and algae, and produces substantially less soot than petroleum diesel.
In addition to these thrusts, the Center researchers are split into working groups that focus on the chemistry of fuel oxidation and how these fuels burn in turbulent environments characteristic of the engine interior. Specifically, theories are developed to predict the properties of new types of fuels and to model their combustion reactions. These theoretical predictions are then experimentally studied using a large array of tools, including laser-based instrumentation and chambers for monitoring combustion processes under extreme temperatures and pressures. The chemical information gained from these theoretical and experimental investigations is then integrated into studies on turbulence and fluid transport to guide the development of new models and simulations.
The Center also supports the training of young researchers through its Energy Fellows program, which places post-doctoral researchers in collaborative, high-risk, high-payoff research projects jointly supervised by two or more principal investigators. In addition, the CEFRC offers a summer school session on combustion that attracts graduates students and professionals from around the world.
The ability of researchers with different areas of expertise to work together within the center has paid off, according to the CEFRC's director, Chung K. Law, the Robert H. Goddard Professor of Mechanical and Aerospace Engineering. "A major CEFRC advance has been the formulation of the first-generation reaction mechanism describing the oxidation of butanol, which is under active commercial development," said Law, who directs the $20 million center, one of 46 DOE Energy Frontier Research Centers. "This significant advance was achieved through the collaborative and coordinated efforts of the CEFRC principal investigators and involved quantum mechanical computation of the reaction kinetics, diagnostics using laser and synchrotron radiation, flame propagation in high-pressure environments simulating the engine interior, and computational simulation of turbulent flames."