Emissions from diesel engines using fatty acid methyl esters from different vegetable oils as blends and pure fuel

Biodiesel is used as a neat fuel as well as in blends with mineral diesel fuel. Because of the limited availability of fossil resources, an increase of biogenic compounds in fuels is desired. To achieve this goal, next to rapeseed oil, other sustainably produced vegetable oils can be used as raw materials. These raw materials influence the fuel properties as well as the emissions. To investigate the environmental impact of the exhaust gas, it is necessary to determine regulated and non-regulated exhaust gas components. In detail, emissions of aldehydes and polycyclic aromatic hydrocarbons (PAH), as well as mutagenicity in the Ames test are of special interest. In this paper emission measurements on a Euro III engine OM 906 of Mercedes-Benz are presented. As fuel vegetable oil methyl esters from various sources and reference diesel fuel were used as well as blends of the vegetable oil methyl esters with diesel fuel. PAH were sampled according to VDI Guideline 3872. The sampling procedure of carbonyls was accomplished using DNPH cartridges coupled with potassium iodide cartridges. The carbon monoxide and hydrocarbon emissions of the tested methyl esters show advantages over DF. The particle mass emissions of methyl esters were likewise lower than those of DF, only linseed oil methyl ester showed higher particle mass emissions. A disadvantage is the use of biodiesel with respect to emissions of nitrogen oxides. They increased depending on the type of methyl ester by 10% to 30%. Emissions of polycyclic aromatic hydrocarbons (PAHs) and the results of mutagenicity tests correlate with those of the PM measurements, at which for palm oil methyl ester next to coconut oil methyl ester the lowest emissions were detected. From these results one can formulate a clear link between the iodine number of the ester and the emission behaviour. For blends of biodiesel and diesel fuel, emissions changed linearly with the proportion of biodiesel. However, especially in the non-regulated exhaust gas components, some deviations from this linear trend were detected.

[1]  K. Cammann,et al.  Interferences of nitrogen dioxide in the determination of aldehydes and ketones by sampling on 2,4-dinitrophenylhydrazine-coated solid sorbent , 1993 .

[2]  K. Cammann,et al.  Development of a method for simultaneous determinations of nitrogen oxides, aldehydes and ketones in air samples , 1993 .

[3]  U. Karst,et al.  Non-porous silica for ultrafast reversed-phase high-performance liquid chromatographic separation of aldehyde and ketone 2,4-dinitrophenylhydrazones , 1997 .

[4]  Christopher A. Sharp,et al.  The Effect of Biodiesel Fuels on Transient Emissions from Modern Diesel Engines, Part II Unregulated Emissions and Chemical Characterization , 2000 .

[5]  Guo-Ping Chang-Chien,et al.  Effects on aerosol size distribution of polycyclic aromatic hydrocarbons from the heavy-duty diesel generator fueled with feedstock palm-biodiesel blends , 2008 .

[6]  C. Yuan,et al.  Reducing carbonyl emissions from a heavy-duty diesel engine at US transient cycle test by use of paraffinic/biodiesel blends , 2009 .

[7]  Axel Munack,et al.  Comparison of exhaust emissions and their mutagenicity from the combustion of biodiesel, vegetable oil, gas-to-liquid and petrodiesel fuels , 2009 .

[8]  L. Ntziachristos,et al.  Effects of biodiesel on passenger car fuel consumption, regulated and non-regulated pollutant emissions over legislated and real-world driving cycles , 2009 .

[9]  Chao He,et al.  Comparison of carbonyl compounds emissions from diesel engine fueled with biodiesel and diesel , 2009 .