Chemical and cell toxicity properties of particulate matter emitted from a diesel engine fueled with biodiesel and ethanol blends.

This study investigates the impact of renewable fuels, specifically three types of biodiesels along with ethanol on the chemical and cell toxicity properties of particulate matter (PM) released from a diesel engine compared to pure diesel. By blending 10 % (by volume) of grape seed biodiesel, spent coffee biodiesel, and eucalyptus oil with diesel, three biodiesel blends (DGs10, DC10, and DEu10, respectively) are produced and subsequently tested. Additionally, an ethanol blend comprising 9 % ethanol and 1 % biodiesel (used as a stabilizer for the blend) is evaluated. The PM compositions from the fuels tested in the present research are also acquired by an Energy Dispersive X-ray Spectroscopy system via a Scanning Electron Microscope. The amounts of water-soluble total carbon (WSTC), water-soluble organic carbon (WSOC), and water-soluble inorganic carbon (WSIC), and their ratios relative to PM mass, are selected to identify water-soluble components via one Organic Carbon Analyzer. To assess the PM volatility and oxidation reactivity, a Thermogravimetric Analyzer is employed. To investigate the adverse effects of PM on cells, four characteristics are examined, which include cell viability, cellular reactive oxygen species (ROS), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). The analysis indicates that both biodiesel and ethanol blends significantly change the chemical and cellular toxicity properties of PM compared to pure diesel, with ethanol blend demonstrating a more pronounced impact than biodiesel blends. Among biodiesels tested, DGs10 has more potential impact than DC10 and DEu10 in changes of PM chemical and cell toxicity properties, specifically in reducing PM carbon content, activation energy (more oxidation reactivity), and cell death rate and increase in PM oxygen content. These characteristics position DGs10 as a promising option for renewable fuel in diesel engines, benefiting human health, the environment, and the efficiency of PM catalysts.