Biodiesels represent more carbon-neutral fuels and are introduced at an increasing extent to reduce emission of greenhouse gases. However, the potential impact of different types and blend concentrations of biodiesel on the toxicity of diesel engine emissions are still relatively scarce and to some extent contradictory. The objective of the present work was to compare the toxicity of diesel exhaust particles (DEP) from combustion of two 1st-generation fuels: 7% fatty acid methyl esters (FAME; B7) and 20% FAME (B20) and a 2nd-generation 20% FAME/HVO (synthetic hydrocarbon biofuel (SHB)) fuel. Our findings indicate that particulate emissions of each type of biodiesel fuel induce cytotoxic effects in BEAS-2B and A549 cells, manifested as cell death (apoptosis or necrosis), decreased protein concentrations, intracellular ROS production, as well as increased expression of antioxidant genes and genes coding for DNA damage-response proteins. The different biodiesel blend percentages and biodiesel feedstocks led to marked differences in chemical composition of the emitted DEP. The different DEPs also displayed statistically significant differences in cytotoxicity in A549 and BEAS-2B cells, but the magnitude of these variations was limited. Overall, it seems that increasing biodiesel blend concentrations from the current 7 to 20% FAME, or substituting 1st-generation FAME biodiesel with 2nd-generation HVO biodiesel (at least below 20% blends), affects the in vitro toxicity of the emitted DEP to some extent, but the biological significance of this may be moderate.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-017-9561-9) contains supplementary material, which is available to authorized users.

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The authors have examined the influence of biocomponents of different origin on exhaust gases emitted from a light duty vehicle with a compression ignition engine. The car was fuelled with diesel fuel containing 20% V/V fatty acid methyl esters and diesel fuel with 13% V/V hydrotreated vegetable oils and 7% V/V fatty acid methyl esters. Commercial diesel fuel containing 7% V/V esters was a reference. The tests were performed on the chassis dynamometer in static engine operating conditions. It was stated that the addition of mentioned biocomponents into diesel fuel slightly changed the concentration of regulated components in exhaust gases with/without after-treatment devices. The presence of bio-components has reduced nitrogen oxide concentration in the treated exhaust gases as compared to the commercial diesel. We observed no trends of changes in unburned hydrocarbon concentrations depending on the type of tested fuels and presence of the diesel particle filter. Unburned hydrocarbons consisted mainly of fractions containing up to five carbon atoms per molecule. Whatever the type of fuel examined, carbonyl compounds such as formaldehyde and acetaldehyde were found only in the untreated exhaust gases.

The paper regards the use of bio-blends consisting of vegetable oil and a higher alcohol as a new component of diesel fuel. The use of rapeseed oil as one of the components eliminates the need energy-intensive conversion rapeseed oil to esters. The use of higher alcohol, such as butanol second generation, obtained directly from biomass will be in accordance with requirements of the European Union on the promotion of renewable energy resources. Experiments with bio-blends were carried out with selected commercial fuel diesel, rapeseed oil, and two alcohols: iso-amyl alcohol and n-butyl alcohol. There was prepared two bio-fuel blends containing 20% by volume bio-blends (BM) and 80% by volume of diesel fuel (D). Comparison of physico-chemical properties of experimental mixtures were done. This article presents the qualitative characteristics of the new fuel composition and evaluate their compliance with the normative requirements. The summary highlights the need to continue research to improve fuel formulations, particularly in the selection of fuel additives.