The downside is that they emit soot and particulate matter. These include sulfates, elemental carbon, organic and carcinogenic compounds, and heavy metals such as arsenic, selenium, cadmium and zinc. The ultrafine particulates, less than 100 nanometres in size, make up 90% of diesel soot pollution and are small enough to penetrate the lung cells. The public-health problems associated with diesel emissions have intensified scientific efforts to develop solutions for reducing these emissions.
Soot is formed by the conversion of the hydrocarbon gases to solid carbon-containing particles, a process that is far from being fully understood. Prof. Dongke Zhang and his research team at the University of Western Australia (UWA) are testing a new catalyst, called ferrous picrate, to improve fuel efficiency and reduce soot emissions. The research is part of an ARC Linkage Project with partner organisations Fuel Technology Pty Ltd and BHP Billiton Iron Ore Pty Ltd.
The team used high-resolution microanalysis in the scanning and transmission electron microscopes in the AMMRF (now Microscopy Australia) at UWA to study diesel soot from fuels, with, and without the catalyst treatments. The catalyst substantially improved combustion in diesel engines, leading to less fuel consumption and a reduction in the overall soot emission. The structure of the soot was the same, with, and without the catalyst suggesting that the catalyst promotes efficient fuel combustion leaving less hydrocarbon available to form soot.
TEM image of soot from the catalyst-treated diesel.
Zhang, et al., Proc. of Combustion Institute 34 (1), 2013
October 24, 2014
