Effects of octane number on exhaust emissions of a spark ignition engine

Abstract

SUMMARYThis paper deals with the experimental study that aims to examine the e!ects of octane number of three di!erent fuel oxygenates on exhaust emissions of a typical spark ignition engine. Three commonly used oxygenates, namely methyl tertiary butyl ether (MTBE), methanol, and ethanol, which were blended with a base unleaded fuel in three ratios (10, 15 and 20 vol%), were investigated. The engine emissions of CO, HC, and NO V were measured under a variety of engine operating conditions using an engine dynamometer set-up. It is found that generally as the octane number of the fuel increases the CO and HC emissions decrease but the NO V emission increases for all three blends. Further, for the leaded fuel (RON of 92), as the speed of the engine increases the CO and NO V emissions decrease but the HC emission decreases. A similar trend was found for MTBE blends also. These emission results are presented in terms of octane number and their e!ects are discussed in this paper.

Energy and exergy analyses of a gasoline engine

“…On the other hand, the effect of RON on detonation has also been studied (Korkmaz, 1996;Bayraktar, 1997;Twu and Coon, 1998;Mogi et al, 1998). Abdulghani (2002) found that as the octane number of the fuel increases the CO and HC emissions decrease but the NO x emission increases.…”

Chemical looping reforming of ethanol for syngas generation: A theoretical investigation

“…As seen from the figure, the Mn-based oxides showed significantly lower CO production above 700 C than other oxygen carriers. The ranking of oxygen carriers based on the selectivity of the oxygen carrier towards CO production (moles) at 1000 C was as follows: Mn 3 (1.89). The minimum moles of carbon monoxide produced were 0.03 moles for Mn 3 O 4 at 500 C and maximum moles of carbon monoxide produced were 1.96 moles for CaSO 4 and Na 2 SO 4 at 1200 C.…”

“…It was observed that due to the fast oxidation kinetics, the enthalpy of oxidation reaction in air reactor did not show much change for different oxygen carriers with change in temperature. It was seen that the exothermicity of oxidation (kJ) at 1000 C decreased in the following sequence: Mn 3…”

“…For example, at 600 C, the yield of carbon dioxide ranged between a maximum of 0.4 moles for CaSO 4 and 0.19 moles for Mn 3 O 4 , while at 1000 C, the CO 2 yield ranged from a maximum of 0.04 moles for CoO and 0.01 moles for Mn 3 O 4 . Accordingly, the ranking of oxygen carriers (for moles of CO 2 generated) at 1000 C was found to be as follows: Mn 3 Similarly, water is also an undesirable product in CLR. It was observed that the water yield decreased with increase in temperature for all oxygen carriers.…”

“…Researchers are trying to produce it from food waste [1] also. Apart from being used additive in gasoline (gasohol) [2,3], it is gaining potential to displace gasoline as the life cycle energy use to produce ethanol is considerably less than that of gasoline and the life cycle GHG emissions released per liter of ethanol produced is an order of magnitude lesser than that of gasoline produced [4][5][6]. The potential of hydrogen/syngas (H 2 +CO) generation from ethanol is studied by many researchers on different aspects such as thermodynamic studies on steam reforming of ethanol [7][8][9][10][11][12][13][14][15][16][17], oxidative steam reforming/autothermal reforming of ethanol [18][19][20][21][22][23], dry reforming [24][25][26][27] and dry autothermal reforming of ethanol [28].…”