Impact of Triacetin as an oxygenated fuel additive to waste cooking biodiesel: transient engine performance and exhaust emissions

The present work investigates the effect of oxygenated fuels on exhaust emission and engine performance under transient operation on a fully instrumented 6-cylinder turbocharged diesel engine with a common rail injection system. A range of oxygenated fuels based on waste cooking biodiesel with triacetin as an oxygenated additive were tested under transient operation. This investigation has shown that increasing the oxygen content of the fuel causes a decrease in exhaust particulate matter and particulate number. Increased oxygen in the fuel decreases the indicated power and the indicated mean effective pressure, while the brake specific fuel consumption increases. Different physical and chemical properties of the fuels are used to interpret the behaviour of the engine under transient operation. Owing to the use of oxygenated fuels, the oxygen ratio was used instead of the air to fuel ratio to better explain the phenomena during combustion.