July 22, 2015Nathan Peters, a mechanical engineering Ph.D. student, has won the best student paper award at the 2015 Laser Ignition Conference. Peters presented the paper, “Laser ignition of methane and biogas near flammability limits,” at the event this April at Argonne National Laboratory in Lemont, Illinois. The paper was co-authored by Henry Morrow ’15 and Professor Ben Akih-Kumgeh. Currently, internal combustion and gas turbine engines use a spark plug to initiate the burning process of fuel and air — a process known as ignition. Despite big improvements to engine technology over the years, ignition methods have remained the same. Using a focused laser beam, a fuel and air mixture can be ignited, even at very low fuel proportions. This is difficult to achieve using a spark plug and desirable for clean combustion. Laser ignition also introduces the ability to ignite various kinds of fuels, including gasoline, biofuels, and natural gas. In the authors’ study, they compare the laser ignition of methane to that of renewable biogas with the dual aim of determining the minimum energy required for ignition and observing how unsuccessful ignition may occur in each case. They use high speed Schlieren imaging and laser interferometry, to see these very fast processes. The paper addresses some acknowledged challenges with using lasers to ignite fuels, such as natural gas in stationary power generation gas turbines. These challenges include variations in required energy under comparable engine conditions. They were able to link variations in required laser energy under different mixture proportions to the prevailing pressures, temperatures, and focusing optics. "What we’re looking at with this paper is something hasn't been studied with laser ignition. I think it's going to be an interesting addition to the literature and will become another diagnostic to be used in the future,” says Peters, “We want to show that there is a lot left to know about combustion and with 80 percent of our power and transportation still dependent on burning fuel, we have a lot of work to do. By exploring the use of renewable biogas, improving fuel efficiency, and reducing emissions, we are able to show that sustainability has a place in combustion that many people don't realize." One day, this technology could become commonplace in electric power generation and even in transportation. By characterizing differences in the laser ignition of bio- and natural gas, the award winning paper is a contribution to the development of combustion systems that will one day be able to burn different fuel gases. Peters continues to work in Akih-Kumgeh’s Thermodynamics and Combustion lab, where his research will continue to advance the science of laser ignition.