While energy costs continue to soar domestically and abroad, mechanical engineering Prof. Arvind Atreya and his team of colleagues and students are pioneering a revolutionary new method of combustion that has the potential to save American industries billions of dollars in energy costs each year.
Though many researchers are working on alternative energy sources for the future such as hydrogen power, Atreya’s new concept could save money and reduce pollution by simply using existing fuels more efficiently.
“We use a lot of energy in manufacturing. That may be going down, but we still use a lot,” Atreya said.
“This creates two problems: One is that it costs a lot, and the second, and more important problem in my mind, is that it causes a lot of greenhouse gases,” he added.
Traditional industrial furnaces burn fossil fuels in order to create heat, often used for melting different metals such as steel. The main problem with traditional furnaces is that over 40 percent of the heat escapes, wasted as exhaust. Atreya thinks he may have the solution.
Called radiative homogeneous combustion, this innovative technique improves upon traditional industrial furnaces by creating even combustion throughout the furnace and recirculating byproducts, which increases efficiency by producing a tremendous amount of heat and radiation. This method can reduce energy loss by 50 percent, Atreya said.
Along with his team, Atreya recently built a ceramic radiative homogeneous combustion furnace for experimental purposes. The furnace is housed in the Francois-Xavier Bagnaoud Building on North Campus.
In a traditional industrial furnace, combustion only occurs where the fuel and air meet inside the furnace and the leftover byproducts quickly escape as exhaust. These byproducts typically include pollutants like soot, nitrogen oxides and carbon dioxide.
However, in a radiative homogeneous combustion furnace, the entire volume of fuel and air within the furnace burns at once and recirculates instead of leaving immediately as exhaust. Burning the entire volume at once helps to burn up many pollutants. This hot gas volume that is formed also helps the heat radiate more effectively. The exhaust eventually exits by passing over unheated fuel and air lines. Heating the fuel and air prior to entering the furnace helps to further recover heat.
Atreya said another secret to the efficiency of homogeneous combustion is the spacing of the nozzles that release the air and fuel into the furnace. As the two substances enter, their temperatures rise as they mix with the recirculating byproducts. The fuel initially begins to form soot. The fuel and air then homogeneously mix together, burning all of the soot in an immensely radiative flame.
Atreya filed last year for a U.S. patent for the furnace on behalf of the University. He is currently conducting experiments in an effort to make the homogeneous combustion concept a reality. Atreya said he is determined to make it work.
“The important thing, in my mind, is if we can get this actually demonstrated, measured, and published, then I have some industry people who are interested in this, and they can come here and see the results,” he said.
“Then there is the possibility of us continuing on a much bigger scale,” Atreya added.
To bring the concept into practical use, Atreya still must research and be able to prove it works.
“What we need to do is understand at what rate we should send the fuel, at what rate we should send the air, what should be the difference between the two such that the homogeneous combustion occurs with the proper site. These are the variables that we are trying to understand,” Atreya said.
The underlying principles of homogeneous combustion can be applied to industries other than manufacturing. Atreya said he speculates that homogeneous combustion could also be used in boilers for the production of electricity. Currently, the automotive industry is researching this concept in what the industry calls “homogeneous compression charge ignition.” The aim is to highly compress well-mixed fuel in the cylinder of the car so that it auto-ignites without the need of a spark — consequently burning homogeneously, increasing efficiency and decreasing pollutants.
For Atreya, the development of fuel-efficient manufacturing comes at a critical time because he believes the planet is on the verge of facing an environmental crisis.
“This is what is left (of our fossil fuels): about 48 years of oil, about 50 years of natural gas, and about a couple hundred years of coal,” Atreya said. “People say don’t worry, we will do nuclear, but there is only about 70 years of uranium left. It’s a shame because nobody worries about it. Everybody is trying to burn coal now because it is cheaper.”
Atreya said evidence gathered from ice core samples in Antarctica shows cyclic carbon dioxide levels over the last 400,000 years cycling between concentrations of 180 and 280 parts per million. But today, carbon dioxide concentration levels are at 360 ppm and expected to reach 720 ppm by 2100, according to the Intergovernmental Panel on Climate Change. As a result of increased carbon dioxide levels, Atreya said by that time the earth’s average temperature is expected to increase four or five degrees Celsius.
These predictions for the future fuel Atreya’s passion for researching more environmentally friendly methods of combustion.
“I am much more interested in making this a great success because of more of my personal reasons than any other reason,” he said. “I want it to be adopted not so much for the patent, but for totally different reasons. I want it to be my little contribution to saving energy.”