Wieslawa Urzedowska’s research while affiliated with Oil and Gas Institute - National Research Institute and other places

It is well known that the reduced stability of FAME diesel fuel blends is of particular threat to diesel engines and especially high pressure common rail (HPCR) systems operation. As has been ascertained, internal diesel injector deposits are more likely to form in modern diesel fuel systems because of their higher operating pressures and temperatures, which can intensify oxidation and decomposition of the chemically unstable components of diesel fuels, particularly those contained in FAME. This paper presents the results of accurate and sensitive evaluation of laboratory test methods for the determination of oxidation, storage and thermal diesel fuel stability, verified via dynamometer engine testing, from the point of view predicting the possibility of threats caused by aged diesel fuel with various FAME contents for HPCR in-system performance.

Two com. gas oils were modified by addn. of a corn. fatty acid Me ester (20 or 30%), conditioned for 16 weeks at 20 degrees C and 60 degrees C and tested in an engine (load 50-100 Nm, rotation 1000-3800 rpm) to det. the torque changes and smoke content in the exhaust gas. The poor biodiesel stability in storage constituted a potential threat to engine performance and operational reliability.

In the Diesel sector the fatty acid methyl esters (FAME’s) – in Europe mostly RME *) (rapeseed methyl ester) and in US mostly SME (soja oil methyl ester) – are used as a various share, % volume blends with the Diesel fuel (B5, B7, B10, B20, Bxx). The present joint project focuses on RME being the most important representative of the biofuels of 1st generation in Europe. The influences of RME blend fuels on emissions and on lube oil deterioration are emphasised. Emissions were investigated on a modern engine with exhaust gas aftertreatment devices like SCR and (DPF+ SCR). Beside the legally limited exhaust emission components some non-legislated like NO2, N2O, NH3 and nanoparticles were measured at stationary and dynamic engine operation. The most important findings are: • the increased percentage of RME w/o aftertreatment causes an increase of NOx by higher engine load and reduction of CO & HC; at transient operation (ETC) these tendencies are less pronounced and only B100 shows an increase of NOx, • with SCR alone there are no differences of NOx and of NOx reduction rate (KNOX) with increasing RME portion; there is lowering of CO & HC, • with DPF+SCR KNOX-values are slightly higher, than with SCR alone, due to the production of NO2 in the catalytic DPF (upstream of SCR), • there is excellent count filtration efficiency of DPF, up to 99.9%; with SCR alone there is usually a small reduction of nanoparticles concentrations (in the range of 10-20%, similar like an usual oxidation catalyst). The paper describes as well significant problems related to the influences of biofuels on engine lube oils deterioration demonstrated by monitoring the engine lube oil aging during its operation in heavy duty (HD) and modern high speed direct injection (HSDI) light duty (LD) engine through the bench tests. Subject to the long run durability engine tests were both: mineral and synthetic engine lube oils with different improved additives packages and viscosity ranges and with different RME-blending ratios in fuel. The research methodology used: standard analysis as well as in house developed innovative methods, extensive analysis of engine lubricants oxidation stability – thin lubricant film oxidation tests and bulk lubricant oxidation tests. It can be stated that: • the presence of bio-components in the fuel has significant impact on multidirectional hastening of engine lube oil destruction processes, • kind of base lube oil, lube oil additives components and RME-portion, as well as engine design and its operating conditions are very essential factors influencing the engine lube oil performance, • the processes taking place in an engine lubricant, influence adversely the limited possibilities of bio-components evaporation from engine lube oil and contribute to initiation of accelerated, deeper engine lube oil oxidation and degradation.

Corn. fatty acid Me ester (FAME) was added to corn. gas oil and used for driving the Diesel engine equipped with modern common rail-type fuel injection system operated under std. conditions. Engine output torque, exhaust gas quality (particulate matter) and changes of quality of lubricating oils (viscosity, acid no., oxidn. stability) were detd. Applicability and limitations of FAME addn. to the gas oil were evaluated. No substantial contraindications were given.

The project is a response to increasing international requirements regarding air quality standards and the European Union demand for increased biofuels share in the fuel market. The project is of great economic and social importance because of steadily increasing number of vehicles on roads. Application of the project results in economy can in long term prospects effect beneficially both environment and human health protection. The rise in biocomponent share of transportation liquid fuel market is a significant element of sustainable development, leading to increase in country’s energy security by lowering dependence on crude oil import. As the utilization of biofuels will limit CO2, the mass of particulate matter, and organic compounds emission, it has also positive impacts on air quality. Development of biofuel market, boosting growth of energy-related agricultural production connected with creation of new jobs, contributes also to activation of country regions. Growing need for fuels and power in economy, with decrease in fossil fuel resources, forces biofuel use development. The research project concerns evaluation of influence of diversified biocomponent content in diesel fuel on emission of particulate matter and other harmful components of modern diesel engine exhaust gases. The research includes also examination of possibility of reducing emission from engines fuelled with these fuels by controlling the exhaust gas recirculation rate. Moreover, the research work comprises detailed analyses of lubricating oil during an extended engine operation period, serving a purpose to assess compatibility of lubricating oils and diesel fuel with biocomponents and potential appraisal of effect of the compatibility lack on the engine emission. The direct objective of the project is to acquire knowledge of new phenomena and processes, having effects on particulate matter emissions from engine fuelled with blends of fossil diesel and biodiesel. The general project aim is development of recommendations on engine controlling, exhaust gas recirculation systems (EGR) and selection of engine oil to achieve limitation of harmful emissions caused by utilization of diesel fuel with biocomponents. One part of the project concerns evaluation of the impact of biocomponents inclusion into fuel on life-cycle GHG emissions and study of toxicology impacts of bioblends.

The paper describes significant problems related to influence of Diesel biofuels on engine lube oil deterioration. It was demonstrated by monitoring the engine oil aging and performance changing during its operation in modern high speed direct injection (HSDI) light duty (LD) engine through the use of bench tests. This engine has been equipped with modern common rail (C R) type fuel injection system. In our study, to determine when and how the engine lubricant properties have been depleted, taking advantage of standard oil analysis as well as innovative methods, made among other things extensive analysis of engine bulk lubricant oxidation tests and thin lubricant film oxidation tests. At the same time aspires to discern diesel biofuels (including different quantity of FAME) influence on direct injection nozzle coking and deposit formation on the inside surfaces of injectors component parts. As a result of conducted investigations has been stated potential hazards of FAME contained in diesel fuel, for engine lubricant degradation and for correct in-system performance of CR system.

W artykule opisano istotne problemy związane z wpływem różnej zawartości biokomponentów (FAME) w paliwach do silników z zapłonem samoczynnym na procesy degradacji smarowego oleju silnikowego. Przedstawiono zmiany właściwości użytkowych oleju silnikowego podczas jego monitorowanej eksploatacji w testach stanowiskowych nowoczesnego silnika wysokoprężnego typu high speed direct injection (HSDI). Silnik był wyposażony w układ wysokociśnieniowego wtrysku paliwa typu common rail (CR). Do określenia ilościowych i jakościowych zmian starzonego w eksploatacji oleju stosowano zarówno metody konwencjonalnych ocen fizykochemicznych jak i metody innowacyjne, prowadząc między innymi rozszerzone analizy odporności na utlenianie oleju w dużej objętości jak i odporności na utlenianie w cienkiej warstwie oleju. Równocześnie, dążono do rozeznania wpływu biopaliwa (o różnej zawartości FAME) na wielkość zakoksowania wtryskiwaczy i tworzenie osadów na wewnętrznych elementach wtryskiwaczy układu CR oraz wynikających stąd zmian wielkości emisji cząstek stałych (PM) przez silnik. Wynikiem przeprowadzonych badań było ustalenie potencjalnych zagrożeń FAME zawartych w oleju napędowym na intensyfikację procesów degradacji oleju silnikowego i funkcjonowanie układu wtrysku paliwa typu CR. The paper describes significant problems related to influence of Diesel biofuels on engine lube oil deterioration. It was demonstrated by monitoring the engine oil aging and performance changing during its operation in modern high speed direct injection (HSDI) light duty (LD) engine through the use of bench tests. This engine has been equipped with modern common rail (CR) type fuel injection system. In our study, to determine when and how the engine lubricant properties have been depleted, taking advantage of standard oil analysis as well as innovative methods, made among other things extensive analysis of engine bulk lubricant oxidation tests and thin lubricant film oxidation tests. At the same time aspires to discern diesel biofuels (including different quantity of FAME) influence on direct injection nozzle coking and deposit formation on the inside surfaces of injectors component parts. As a result of conducted investigations has been stated potential hazards of FAME contained in diesel fuel, for engine lubricant degradation and for correct in-system performance of CR system.

Six lubricating oil-motor fuel pairs were tested for changes of kinematic and dynamic viscosity, acid no. and thin-layer oxidn. resistance for 400 h. The presence of biocomponents in the fuel resulted in an accelerated degrdn. of the fuel.