Abstract
Research and /or Engineering Questions/Objective: Biodiesel is made from renewable sources of energy. It is biodegradable, non-toxic, CO2 neutral, and its application contributes to the reduction of harmful gases emission in urban areas. Biodiesel may be used alone or with diesel fuels in various blend rations. Most producers allow application of a 5% biodiesel blend without special adjustments in the vehicles, although there is a tendency to use a 20% biodiesel blend. Penetration of biodiesel (or blend) into the oil causes its dilution and poses a particular problem since the fuel does not evaporate, but accumulates in the oil and causes changes of its properties.
Methodology: Our study was carried out by using 20% biodiesel and 80% diesel fuel (B20). The impact of biodiesel on the quality of engine oil for passenger cars has been studied. The test was performed according to the method ASTM D6594 and CEC L-78-T-99 method (known as Volkswagen TDI test). The test is used to evaluate the performance of engine oils with respect to ring sticking and piston cleanliness (deposit control). Oil test was done after certain time periods (after 12 h, 24 h, 39 h, 48 h, and 54 hours of work). The changes in physical and chemical characteristics of oil were determined by FT-IR (Fourier Transform-Infrared) spectrophotometry, and wear metals by AAS (Atomic absorption spectrophotometer). Upon completion of the test, the engine was disassembled; weight measurements were conducted as well as visual inspection of the status of vital engine parts which also has been measured prior to the test.
Results: The test results show that no particular wear of engine parts occurred. In the engine cylinders, spot-like changes in color were observed which are not common in the same diesel fuel tests. Oil viscosity increased during the test, but within acceptable values. During the experiment there was a slight decrease in the Total base number (TBN) and increase Total Acid Number (TAN). Amount of soot was significantly increased. The possibility to reduce the amount of soot also was analysed.
Limitations of this study: Although conditions in the laboratory testing largely simulate actual operating conditions of engine oil but there is deviation of engine operating regimes compared to the actual road conditions.
What does the paper offer that is new in the field in comparison to other works of the author: Using B5 blend, till now it has shown no significant changes occur in the oil even under critical engine operating conditions, but engine operating using B10 and B20 has not been studied enough.
Conclusion: It can be concluded that usage of B20 do not change significantly oil characteristics and oil has considerable performance reserve. Weight loss and Wear-out of parts of engine was little higher when B20 was used, but in the permitted limits.
KEYWORDS – Biodiesel blend B20, Engine oil testing, Wearing out of engine parts.