Due to the large energy demand of traditional fuels and therefore its limitations, the urgent need for energy from renewable/sustainable sources such as biofuels has emerged. Liquid biodiesels, bioalcohols, vegetables oils of different kinds and bioethers have the potential to address the energy need and at the same time are believed to lessen the adverse effects on our environment. It has been reported that biodiesel can significantly reduce gaseous harmful emissions and volatile organic compounds. However, little is known regarding the carbonaceous particles (soot particulates) produced from biodiesels and/or vegetable oil/diesel blends. Due to their nanometer-size, carbon particulates have great potential for environmental contamination and health effects, even at greater levels than other gaseous combustion emissions. Particles of nanometer size (billionth of a meter) that are inhaled have a high probability of deposition into the lungs and are likely to trigger or exacerbate respiratory diseases. In some cases these hazardous ultra fine particles can pass directly through capillary walls into the bloodstream initiating severe diseases in addition to respiratory health effects. The smaller the size of the particles, the more harmful they become. Moreover, due to their size and light weight, these particles can be suspended in the air for weeks before settling. The PI?s preliminary results show that carbon particulates produced from two different biodiesels have significantly smaller diameters compared to those produced in diesel fuel under the same experimental conditions. The preliminary findings contradict the notion that combustors running with oils are likely to produce large (less harmful) or coarse particles. Therefore, there is a critical need to understand the growth processes of these ultra-fine hazardous particulates generated from these new emerging fuels. A co-flow burner is used to create the flames. The approach of this project will be as follows. Objective 1: study the effect of soot concentrations (particle population) using different biodiesels and blends with various percentages of diesel fuel using the laser extinction technique. The effect of soot concentration will also be studied by creating the flame medium with different oxygen contents ranging from 21% to 100% O2. The laser extinction technique allows for an instantaneous, non-intrusive measurement of local soot concentration in a variety of flames. Objective 2: obtain particle distributions and study the particle morphology (size, nanostructure, and degree of agglomeration) of the carbon particulates by extracting them using the thermophoretic sampling technique. To accomplish objective 2, samples of carbon particulates will be analyzed using electron transmission microscopy (TEM) and high resolution TEM. Objective 3: Efforts will also be devoted to obtain concentration profiles of major gaseous chemical species, including CO, CO2, O2, SOx, and NOx. The emissions concentrations will be obtained by scanning the flame in axial and radial directions as a means of producing spatially resolved data. This research seeks to obtain a fundamental understanding of carbonaceous particles and other harmful gaseous emissions produced from various biodiesels and blends.
Given the fact that this research project will take place in Oklahoma which is historically known for its Native American heritage and population, the broader impact of this proposal focuses on the recruitment of Native American students into science and engineering. The first Educational Proposition focuses on a plan to stimulate interest and as a result increase the participation of Native Americans in undergraduate and advanced level engineering education. In order to have a broader impact, this Educational Proposition will also focus on the mentoring of secondary level students. The second Educational Proposition focuses on stimulating and increasing the participation of domestic students in an advanced education in engineering. Efforts will be targeted toward highly talented students who are in their third and fourth year of their undergraduate studies. OU has an exceptional pool of talented undergraduate students to draw from as evidenced by the fact that OU is consistently ranked #1 in National Merit Scholars per capita for public universities in the nation. Approximately half of these National Merit Scholars matriculate in the College of Engineering, thus constituting a large number of potential graduate students to be recruited locally as well as nationally.
