Author/Authors :
Tobib, H.M Department of Mechanical and Manufacturing Engineering - Faculty of Engineering - Universiti Putra Malaysia - UPM Serdang, Malaysia , Hairuddin, A.A Department of Mechanical and Manufacturing Engineering - Faculty of Engineering - Universiti Putra Malaysia - UPM Serdang, Malaysia , Nuraini, A.A Department of Mechanical and Manufacturing Engineering - Faculty of Engineering - Universiti Putra Malaysia - UPM Serdang, Malaysia , Mossa, M.A.A Department of Mechanical and Manufacturing Engineering - Faculty of Engineering - Universiti Putra Malaysia - UPM Serdang, Malaysia , Noor, M.M Universiti Malaysia Pahang - Pekan - Pahang, Malaysia , Ayob, S.I Mutiara Damansara - KLK Oleo - Menara KLK - Jalan PJU - Petaling Jaya - Selangor, Malaysia
Abstract :
The study of palm oil-based biodiesel, which is widely available in tropical
climate countries, in HCCI engines are being focuses. A single cylinder
diesel engine with a port fuel injector and heated intake air were used to
operate the HCCI engine at 2700 rpm using palm oil-based biodiesel. The
fuels used in this study are diesel and palm oil-based biodiesel with four
different blends of 5%, 10%, 15%, and 20% (POB5, POB10, POB15, and
POB20, respectively). The parameters varied for the study were different
lambdas, λ of 3.1, 2.9, 2.6, 2.4 and intake air temperature of 70, 80, and
90°C. When using diesel fuel on HCCI mode, it is found that the engine
power, torque, and BTE are lower and fuel consumption is higher
compared to conventional Compression Ignition Direct Injection (CIDI)
mode. The in-cylinder pressure pattern for HCCI mode shows that the
combustion is advanced, and the in-cylinder pressure peak is higher at rich
mixture compared to CIDI mode. The in-cylinder pressure decreases in the
case of higher amount of biodiesel. Combustion intensity for biodiesel fuel
is lower, which affects the heat release rate, whereas a high intake
temperature triggers the combustion easily, enhances the fuel mixture
auto-ignition proses. Increasing the amount of biodiesel will increase the
NOx emissions insignificantly, however it is still lower than that of CIDI.
This is due to the fact that there are more oxygen contents in biodiesel.
The emissions of HC and CO were reportedly higher in many literatures
when the engine operates in HCCI mode. The same pattern occurred in
this study, where the emissions of HC and CO were higher than that of
CIDI mode. However, it was found that, the HC and CO were improved
(decreased) in HCCI mode when increasing the POB content, and so with
the CO2. This means that POB based biodiesel improved the emissions of
HCCI engines. Therefore, it can be concluded that palm oil biodiesel is the
future potential to be used as a replacement to the conventional diesel in
HCCI engine, as it provides an alternative way to reduce the dependency
on fossil fuel, thus decreasing the percentage of emission levels.
Keywords :
Port Fuel Injector , palm oil biodiesel , diesel , HCCI
