José Madero holds an associate degree from Miami Dade College and a bachelor’s degree from Union College, both in mechanical engineering. He joined Washington University in Saint Louis and LACER in August 2013. He had previously studied the effect of moisture content on biomass-coal cofiring systems and is currently investigating the combustion of high water content fuels.
Recent concerns over emissions of CO2 from fossil fuel combustion have prompted strong interest in developing carbon neutral or carbon negative processes to supply electricity. Biofuels are considered an attractive means of supplying renewable energy, as they have low net emissions of greenhouse gases since CO2 is removed from the atmosphere during biomass growth. When biomass grows, it captures and stores energy from the sun, but it also captures CO2; so with appropriate technologies, the potential exists for using biomass as a means of removing CO2 from the atmosphere while providing energy — that is, carbon negative power generation.
Biomass intrinsically has high moisture content, either during growth (e.g., algae) and/or during processing (e.g., ethanol). During the processing of biomass or waste, water is separated in an energy-intensive step. For example, 25% of the energy content of ethanol is consumed by water removal. Thus, there are many opportunities to utilize high moisture content biomass if the energy content of these fuels can be extracted. The combustion of mixtures of fuel and water — for example, ethanol, coal-water slurry, oil-water emulsion, wastewater, bio-oil — has been the subject of extensive research since the 1970s. Nonetheless, most of the previous studies aimed to operate with minimal water content. With the advent of oxy-combustion, this is no longer a necessary requirement, and our current work aims to address combustion of fuels that are heavily diluted with water (e.g., > 50% water content). The following topics are currently being investigated: the liquid mass transfer mechanism in droplets and sprays; the influence of preferential vaporization of volatile fuels on flame stability; the flame characteristics for volatile and non-volatile fuels having high water content; and the mechanisms of flame stabilization for the different fuel mixtures.