Swedish Diesel Research Articles

Penetration of Poisons Along the Monolith Length of a V2O5/TiO2 Diesel SCR Catalyst and Its Effect on Activity

Catalysts used for selective catalytic reduction of NOx on diesel engines were deactivated for 890 and 2299 h in the exhausts from a diesel engine running on Swedish diesel fuel mark 1. The deactivated catalytic monoliths (100 mm long) were cut in 10 mm pieces along their axis and were characterized by physicochemical methods as well as by determination of the activity in the reduction of NOx by NH3 and in the oxidation of NH3 by O2.Graphic

Energy flows and efficiencies as indicators of regional sustainability – A case study of Jämtland, Sweden

An analysis of energy and material flows has been elaborated for the Swedish region Jämtland with the aim of monitoring and comparing regional sustainability by following the work energy flow method developed in a study of the Danish island of Samsø (Nielsen & Jørgensen, 2011).In the region of Jämtland about 46,000 TJ of energy flows into society, of which 88% is renewable. From this an amount corresponding to 30,800 TJ is exported as electricity from the region, while another 410 TJ is exported as waste to be incinerated. The remaining part, about 15,200 TJ (63% renewable), drives Jämtland. From an energy flow perspective, the most important production from the region, apart from electricity production, is biomass from the forest: 49,000 TJ estimated as energy content in the biomass harvested. Another 55,000 TJ is added to the standing biomass every year as forest growth (only productive forest land area has been calculated).Some suggested indices of sustainability have been calculated and Jämtland shows high values. However, it will be a challenge to transform the quite large transport sector of Jämtland, and therefore the potential to become fully sustainable (ref to indexes used for the Samsø study) might not be quite as high. In order to reduce the use of non-renewable energy, a major conversion of the transport fleet is needed, and this should be given high priority. The private sector is the largest single user of non-renewable energy (2,200 TJ). One successful transition is the Swedish diesel mix with 19% FAME/HVO derived from vegetable or animal sources and regarded as renewable. The consumption of FAME/HVO is predicted to increase significantly, increasing the importance of the forest as a source.A sustainability analysis based at work energy flows shows for both Samsø and Jämtland that large natural resources producing a high work energy output combined with low work energy use due to low population density, gives high sustainability indicators. This indicates that regions with high population density and the absence of natural resources (high import), as in most regions in the world, will show low sustainability indicators.

Effects of fuels, engine load and exhaust after-treatment on diesel engine SVOC emissions and development of SVOC profiles for receptor modeling

Diesel exhaust emissions contain numerous semivolatile organic compounds (SVOCs) for which emission information is limited, especially for idling conditions, new fuels and the new after-treatment systems. This study investigates exhaust emissions of particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and sterane and hopane petroleum biomarkers from a heavy-duty (6.4 L) diesel engine at various loads (idle, 600 and 900 kPa BMEP), with three types of fuel (ultra-low sulfur diesel or ULSD, Swedish low aromatic diesel, and neat soybean biodiesel), and with and without a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF). Swedish diesel and biodiesel reduced emissions of PM2.5, Σ15PAHs, Σ11NPAHs, Σ5Hopanes and Σ6Steranes, and biodiesel resulted in the larger reductions. However, idling emissions increased for benzo[k]fluoranthene (Swedish diesel), 5-nitroacenaphthene (biodiesel) and PM2.5 (biodiesel), a significant result given the attention to exposures from idling vehicles and the toxicity of high-molecular-weight PAHs and NPAHs. The DOC + DPF combination reduced PM2.5 and SVOC emissions during DPF loading (>99% reduction) and DPF regeneration (83–99%). The toxicity of diesel exhaust, in terms of the estimated carcinogenic risk, was greatly reduced using Swedish diesel, biodiesel fuels and the DOC + DPF. PAH profiles showed high abundances of three and four ring compounds as well as naphthalene; NPAH profiles were dominated by nitronaphthalenes, 1-nitropyrene and 9-nitroanthracene. Both the emission rate and the composition of diesel exhaust depended strongly on fuel type, engine load and after-treatment system. The emissions data and chemical profiles presented are relevant to the development of emission inventories and exposure and risk assessments.

Dieselization in Sweden

In Sweden the market share of diesel cars grew from below 10 per cent in 2005 to 62 per cent in 2011 despite a closing gap between pump prices on diesel oil and gasoline, and diesel cars being less favored than ethanol and biogas cars in terms of tax cuts and other subsidies offered to “environment cars”. The most important factor behind the dieselization was probably the market entrance of a number of low-consuming models. Towards the end of the period a growing number of diesel models were able to meet the 120g CO2 threshold applicable to “environment cars” that cannot use ethanol or biogas. This helped such models increase their share of the diesel car market from zero to 41 per cent. Dieselization appears to have had only a minor effect on annual distances driven. The higher average annual mileage of diesel cars is probably to a large extent a result of a self-selection bias. However, the Swedish diesel car fleet is young, and the direct rebound effect stemming from a lower variable driving cost may show up more clearly as the fleet gets older based on the assumption that second owners are more fuel price sensitive than first owners.

Enhancing the lubricity of an environmentally friendly Swedish diesel fuel MK1

The lubricity of diesel fuel has a direct effect on the service life of the fuel injection equipment, and when alternative fuels are specified, is of vital importance. One such fuel is the Swedish diesel fuel, MK1 which contains low levels of sulphur and low lubricity. This paper investigated the use of ultra low sulphur diesel (ULSD) and fatty acid methyl esters derived from rapeseed (RME) blends to improve MK1 lubricity. Fuel lubricity was assessed using a high frequency reciprocating rig. The wear scar diameter of the ball specimen was measured using optical microscopy while the wear profile and surface roughness of the disc were analysed using a profilometer. Scanning electron microscopy with an energy dispersive spectrometer was used to evaluate the microscopic topography and chemical compositions of the surfaces. Results confirm that MK1 has poor lubricity when compared to other base fuels. Of the blended fuels, ULSD showed little improvement. However, a small percentage of RME improved the lubricity of both the pure MK1 and the blends. Analysis of the worn surfaces indicated that chemical compositions of MK1 did not adsorb and react as well when compared with those of ULSD, RME and selected blended fuels.

저온 디젤 연소에서 발생하는 탄화수소 종 분석

Low temperature diesel combustion was achieved via a combination of late injection timing ( CA BTDC to CA BTDC) and heavy exhaust gas recirculation (37% to 48%) with ultra low sulfur Swedish diesel fuel in a 1.7L common rail direct injection diesel engine. When injection timing is retarded at a certain exhaust gas recirculation rate, the particulate matter and nitrogen oxides decease simultaneously, while the hydrocarbon and carbon monoxide increase. Hydrocarbon speciation by gas chromatography using a flame ionization detector reveals that the ratio of partially burned hydrocarbon, i.e., mainly alkenes increase as the injection timing is retarded and exhaust gas recirculation is increased. The two most abundant hydrocarbon species are ethene which is a representative species of partially burned hydrocarbons, and n-undecane, which is a representative species of unburned hydrocarbons. They may be used as surrogate hydrocarbon species for performing a bench flow reactor test for catalyst development.

Sources of Hydrocarbon Emissions from Low-Temperature Premixed Compression Ignition Combustion from a Common Rail Direct Injection Diesel Engine

Low-temperature premixed compression ignition combustion (PCI) discussed in this study is achieved via late injection timing (close to top dead center) and heavy exhaust gas recirculation (EGR) using ultra low sulfur Swedish diesel fuel (sulfur content less than 15 ppm). PCI obtains a simultaneous decrease in particulate matter (PM) and oxides of nitrogen (NOx), as where injection timing is retarded, as opposed to conventional combustion, where a PM-NOx trade-off is observed. In PCI, hydrocarbon (HC) and carbon monoxide (CO) are increased, and must be removed using aftertreatment. In order to understand the sources of HC from the PCI regime, gas chromatography with a flame ionization detector is employed to perform exhaust HC speciation at three EGR rates and three injection timings. Volatile HC, semi-volatile HC, and CO increase as the injection timing is retarded or EGR is increased. Retarded injection timing or increased EGR reduces peak cylinder bulk temperature and thereby increases the yield of CO and volatile HC (mostly C1–C3). Retarded injection timing or increased EGR also increases ignition delay, which increases over-mixing and causes more mixture to become so lean that combustion ceases and the output of semi-volatile HC species (mostly unburned C10–C12 fuel) is increased. Volatile HC species are increased more than semi-volatile HC species, which results in a shift to a lighter exhaust HC mixture as injection timing is retarded or EGR is increased.