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This work presents a new methodology to evaluate intake valve and combustion chamber deposits formation on port injection flexible fuel spark-ignition engines. This test methodology was adapted from ASTM 6201 standard, using a commercial Brazilian engine that can be run with blends of gasoline and ethanol in any proportion from pure gasoline to pure ethanol. It also describes every step of the methodology development, test conditions and the main criteria discussed by workgroup created by The National Agency of Oil, Natural Gas and Biofuels - ANP to propose a suitable standard for Brazilian spark ignition engine's fuels. This methodology will also be used to evaluate the results of detergent dispersant additives that may comply with the compulsory Brazilian gasoline additivation that will be due at January 2014.

This paper assesses the use of E85 fuel in Brazilian flex fuel light duty vehicles. E85 is composed of 85% of anhydrous ethanol and 15% of gasoline in volume base. Advantages and disadvantages of the E85 use are presented in comparison to hydrated ethanol (H100) that is currently available in the Brazilian market. Additionally, the blend H81 made by 81% of hydrated ethanol and 19% of E22 gasohol (gasoline with 22% of anhydrous ethanol), resulting on a fuel with 15% of gasoline was also investigated. The main difference between E85 and H81 is the water content due to the use of hydrated ethanol. As the E85 is not available in Brazil, this is the correspondent feasible mixture with commercial fuels in the country. Both fuels were assessed and compared to hydrated ethanol regarding cold start, cold driveability, speed recovery, pollutant emissions, fuel economy and deposit formation with engine and vehicle tests performed in the Petrobras Research Center (CENPES) laboratories.

The purpose of this work is to describe a technique that is capable of determining the induction system deposits (ISD) tendencies of gasoline, applying the ISD apparatus developed at Southwest Research Institute (SwRI®). The results showed that temperature, fuel quality, and presence or absence of lubricant oil in the sample affect the quantity and the characteristic of the deposits. Engine tests, done in a Fiat 1.4 tetra fuel engine, were carried out in order to verify the intake valve deposits (IVDs). Another bench technique, the Intake Valve Deposits Apparatus (IVDA) proposed by SwRI®, was also evaluated. It was observed that the results obtained with ISD have qualitative similarity with the trend observed for the results in the engine and in the IVDA tests. So, it can be concluded that bench-scale tests are a promising alternative to make a first screening of the gasoline samples prior to the engine tests.

In the last decades, PETROBRAS has strongly contributed to improve its gasoline quality to attend engines and environment regulations evolutions. In this context, PETROBRAS Research and Development Center (CENPES) has been performing repeated evaluation studies about the influence of the gasoline properties in the pollutant emissions (THC, CO, NOx, Aldehydes and CO2). This paper presents the statistical modeling study made by Vehicles Test Laboratory at CENPES that allows predicting these pollutants, from gasoline composition variation, mainly the aromatics, olefins and sulfur contents.

This study makes a technical evaluation on the possible impacts produced by a 22% to a 26% of fuel anhydrous ethyl alcohol (FAEA) content increase on gasoline, concerning exhaust emissions (CO, HC, NOx and Aldehydes), fuel consumption, vehicle performance (drivability) and engine performance on test bench. Performance curves of an 2.0 MPFI engine, emission and consumption tests on chassis dynamometer and drivability tests on three vehicles representing the national fleet are shown, with technologies considering the three limits established by Automotive Vehicles Air Pollution Control Program - PROCONVE. Results indicate fuel consumption increase and no significative changes of emissions, pursuant to anhydrous alcohol content increase above 22% vol. on gasoline.