EXPERMENTAL STUDY OF THE POLLUTANTS EMISSION FOR A SPARK IGNITION ENGINE FUELED WITH GASOLINE AND BIO-ETHANOL BLENDS

The gasoline is fossil fuel, which is limited in reservoirs and produces pollutions during combustion. This causes varieties of study in search of alternative fuel for SI engine. Bioethanol has been used as an alternative fuel or fuel additive in spark ignition (SI) engines for years; because ethanol fuel is, higher combustion velocity could help increase the combustion efficiency and minimize the emission pollution .This study is an experimental investigation of the effect of bioethanol addition to gasoline on the exhaust emissions in terms (carbon dioxide CO2, carbon monoxide CO, unburnt hydrocarbons UHC and nitric oxide NOX) of a spark ignition engine of a spark ignition engine. The tests were conducted at controlled throttle variable speed condition over the range of 1200 to 2000 rpm with intervals 400 rpm with compression ratios CR= 7,8,10, and 11 using pure gasoline and bioethanol gasoline blends. Ethanol energy ratio (EER) was set to be (5%, 10%, and 15%). The blending of gasoline and bioethanol is done on energy replacement basic. The bioethanol used is produced from Iraqi date crop (zehdi).At each of the three designated engine speeds, the torque was set as (0, 3, 7, 10, 14) N.m. It is found that ethanol blending reduces carbon monoxide and unburnt hydrocarbon in the exhaust gases by about 45% 40.15% respectively and increases the nitric oxide emissions and carbon dioxide in the exhaust gases by about 16.18% 7.5% respectively.It is found also that the increase of load and speed causes increasing in pollutants concentration (CO2, and, NOx), while decrease in the (CO, HC). Finally, the result show that increasing the compression ratio causes the exhaust emissions namely (CO2 and NOX) to decrease while the (CO and HC) to increase.