Tribological Performance of Various Types of Biodiesel

Abstract

Lubricity is a critical property of diesel fuel because it affects engine performance. Current and future regulations are expected to reduce the sulfur content of diesel fuel. Low lubricity (i.e., low sulfur content) increases diesel engine wear and damages the fuel injection system. Alternative types of fuel have reduced diesel engine exhaust emissions and improved the friction and wear properties of engine parts.
Four types of diesel fuel, pure petrodiesel, soybean oil, palm oil, and waste edible oil (WEO), were compared for their fuel properties, engine performance, and emission characteristics. A series of tests was performed using various types of diesel fuel. The ball-on-ring wear testing method was used as an analytical tool for this purpose. The lubricating efficiency of the fuels was estimated using a photomicroscope to measure the average width of the wear scar produced on the test ring.
The wear experiments showed that the wear scar widths were 3.48 mm, 2.76 mm, 2.90 mm, and 2.93 mm for lubrication of the pure petrodiesel, soybean oil, palm oil, and WEO, respectively. Lubricities of this diesel are as follows: soybean oil > palm oil > WEO > pure petrodiesel. The ability of biodiesel to be highly biodegradable and its superior lubricating property when used in compression ignition engines make it an excellent fuel. This detailed experimental investigation confirms that biodiesel can substitute mineral diesel without any modification in the engine. The use of biofuels as diesel engine fuels can play a vital role in helping the developed and developing countries to reduce the environmental impact of fossil fuels.