| To meet the twin problems of fuel lacking and air pollution caused by the growing use of fossil fuels, Chinese government had determined to promote alternate renewable, clean burning fuels. Ethanol, one of widely used and renewable eco-friendly fuels can be used as a blend with gasoline to meet the growing demand of oil consumption. Presently about 10 provinces are using E10 ethanol-blended gasoline. Small gasoline engines such as motorcycles and off-road small spark ignition engines, so called utility engines, should have attracted attention for huge amount of production. Along with the rapid growth of E10 consumption, it is urgent to study effects brought about by ethanol. Author hereby selected small gasoline engines as research object to investigate applicability and emission control of ethanol-blended gasoline.The first laboratory in China for general utility engine emission tests was estabilished by research division of author following requirements of American EPA and certificated by CNACL. Emission regulations of overseas contries have been studied and the effects of ethanol and gasoline blends on the performance and regulated emissions (CO, HC and NOx) of typical utility engines made in China have been experimentally evaluated. To accomplish this task the engine fuel supply system was not modified. Comprehensive measurements of the performance parameters as well as the emissions using gasoline, ethanol-gasoline blends were performed. Furthermore, similar works executed on typical motorcycles. Detailed test results show that E10 could help small engines to reduce exhaust emission of CO and HC in some degree, but for NOx is half-and-half. Further research indicated that fuel supply decreased along with the increase of ethanol mixture ratio.Ethanol as oxygen additive has potential dangerous that might make poisonous organic compound exhaust more than that from pure gasoline fueled engines. This paper is concern to methods research of sampling, separating and analysis of unconventional exhaust emissions. Not only the method of Gas chromatogram and mass spectrum but also attempt to some new methods. Aim at the difficult problem of formaldehyde measurement, author enrich formaldehyde by water and then measured by means of ultraviolet-visible. The minimum measuring limits of formaldehyde was remarkably promoted to 0.02×10-6 (V/V). Furthermore, selected Solid-Phase Extraction Column with dinitrophenylhydrazone (DNPH) to catch aldehyde and ketone by chemical reaction which is so called ramification, and then wash by C2H3N and measured by Liquid- chromatogram. Up to now, more than 20 different organic have been determined. It shows that formaldehyde as high toxicity exhaust emission is much more than that from gasoline.Selected running mode emission test data to indicate conversion ratio of motorcycle catalytic converters before and after 10,000km road aging tests. Then aged converters were analyzed to investigate reasons for deactivity. Different carbon polymer was found from different fuel as primary explanation for de-active. An evaluation testing equipment for catalytic converters was developed and then took light off temperature to indicate converter's activity. Some converter samples were aged together under the condition of real engine exhsuat gas which was fueled by gasoline and ethanol gasolines respectively. Performance of those samples show it is necessary to develop and match converters depending on different fuel supplied by regions.Contrasting durability tests show that engines fueled by ethanol gasoline appear more serious abrasion and more quantity of fuel supply characteristics for EFI system. Scraping phenomena happed on both two 2T motorcycles. Author also attached importance to standardization work root in study and research. Up to now, have drafted the first Chinese national standard for multipurpose utility engines emission control and other two standards for motorcycle catalytic converter and SAI evaluation test methods.
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