Pollutant emissions from internal combustion engines using ethyl-alcohol-water blends and commercial gasoline as fuels

The use of alternative fuels in Brazil mainly ehtyl-alcohol-water blends, has created the necessity of determining the pollutant emission pattern under typical design operating conditions aiming the establishment of a pollution control policy. Papers that were issued up to 1982 don't present any study of emissions from internal combustion engines using such fuel under variation of design parameters in well controlled laboratory conditions. Although the formation of carbon monoxide and nitric oxide during the operation of spark ignited internal combustion engines are well known, the emissions of aldehydes and hydrocarbons are not well understood up to date. In this work, a monocylinder engine was tested under controlled conditions and its emissions, basically nitric oxide, carbon monoxide and aldehydes, were measured. As a main result of this study, aldehydes profiles were obtained for several variations in parameters such as air-fuel ratio, compression ratio and water content of blends.