A very recent experiment conducted in the International Space Station by a team lead by Forman Williams established that flames could burn at much lower temperatures by using fuel more efficiently given the right atmospheric condition. Williams, a professor of Mechanical and Aerospace Engineering at the University of California stated this as a life altering event. The findings from this experiment could be used to make much more fuel efficient car engines that give out lesser amount of pollutants. In the current conditions the common fuels used give out a combination of oxides of carbon, sulphur and nitrogen (also represented as NOx) which are very harmful for the environment.
The details of the study published in the journal Microgravity Science and Technology it was shown that in microgravity conditions flames burn at a much lower temperature. The experiment, very simply speaking consisted of Heptane fuel droplets which were ignited in microgravity conditions. Although to the naked eye it looked like the flame was extinguished, the sensors used detected cool flames which were outside our visible spectrum. This kind of cool flame can occur in a number of atmospheric conditions, very comparable to Earth’s; atmospheres diluted with nitrogen, carbon dioxide and helium. The byproducts of combustion are quite toxic and include formaldehyde and carbon monoxide; however they eventually burn off as well resulting in clean and efficient fuel combustion.
Research shows that these cool flames are a result of chemical reactions which are not facilitated under normal circumstances inside the earth’s atmosphere. The main difference between the conditions in the Space Station and the earth’s surface was buoyancy. Buoyancy causes the gaseous droplets to dissipate inside the earth’s atmosphere. However in outer-space the lack of buoyancy allows these very droplets to stick together and be in the higher temperature zone. This little difference in time allows the chemical reactions to occur optimally that allows ideal combustion and cool flames. The normal blazes on this planet have a temperature of approximately 2240 degrees to 3140 degrees Fahrenheit or 1225 degrees to 1725 degrees Celsius. But these cool flames burn with a temperature between 440 degrees to 980 degrees Fahrenheit or 227 degrees to 527 degrees Celsius.
The main challenge for adoption of the findings of this elaborate research will require the right mix of fuels to generate cool flames on earth. The findings are quite promising and can be applied in the automobile engineering industry to develop more fuel efficient cars that will not contribute to global warming. To research on the concerned matter NASA is taking a new initiative to design a series of experiments. This will be known as the Cool Flame Investigation and it is scheduled to start next winter. For about a year the scientists will conduct experiments and try to figure out the perfect combination of fuels that will allows cool flames to persist in earth’s atmosphere under uncontrolled environments. For real life application of the discovery the results have to be first optimized through a series of experiments, the likes of which will be conducted by NASA due next winter.
The research team lead by Williams also emphasized that the results of this research will be best replicated on the International Space Station due to the microgravity requirement. That is a must for cool flames to occur and persist. All these experiments can be conducted inside the Multiuser Droplet Combustion Apparatus which can generate as well as ignite the droplets of Heptane like gaseous fuels under different simulated atmospheric conditions. The chamber is fully equipped with high quality sensors and video cameras that record the progress of the experiment and prevent the production of artifacts. The Combustion Integrated Rack is the facility which holds the Combustion chamber. This is approximately 5.5 feet tall and has the dimensions of a comparable bookcase. With its unassuming stature it is powerful enough to sustain temperatures up to a few thousand Degrees Fahrenheit. It is fully equipped to record and transmit data to the ground with impeccable accuracy. According to Williams himself, “Things that can happen out there are quite impossible down here”. He has been working with NASA on fire research and safety since 1970’s and the experiments are controlled by NASA’s John Glenn Research Center in Cleveland.