Identifying the potential of waste cooking oil, waste lubricating oil, and tar as alternative fuel for bioethanol processing stoves

Abstract The air mass flow rate greatly influences the optimal flame temperature in the combustion process. Stoves with unstable combustion temperatures result in non-optimal flame temperatures. An unstable combustion temperature is shown by the flame which tends to dim and the temperature decreases. Another impact is the emergence of smoke or exhaust gas which will cause air pollution. The temperature in the stove must be maintained constant to produce a perfect flame. The perfection of combustion is influenced by three factors, namely the ratio of air and fuel (air-fuel ratio, AFR), homogeneity of the mixture, and burning temperature. Based on those situations, this research aims to obtain the ideal air mass rate to obtain good ignition results and low emission values. Three types of liquid waste in the form of waste lubricating oil, waste cooking oil, and tar oil were chosen in the experiment. Gas chromatography-mass spectrometry (GC-MS) testing has obtained chemical formulas for waste lubricating oil, waste cooking oil, and tar. The stoichiometric AFR for these three wastes can be calculated after the chemical reaction on the combustion of each fuel has been determined. AFR stoichiometry is used as a basis for determining the ideal air mass flow rate applied in the experiment. The experimental results show that the highest flame temperature for the waste lubricating oil is 876.8°C at an air mass flow rate of 0.00359 kg/s. The highest flame temperature in combustion with the waste cooking oil fuel is 891.3°C at an air mass flow rate of 0.00213 kg/s. For tar fuel, optimal combustion occurs at an air mass rate of 0.00343 kg/s and produces the highest flame temperature of 787.1°C.