Fuel Blending and Analysis for the Auto/Oil Air Quality Improvement Research Program

This paper provides an overview of the blending techniques and analytical methods used to formulate the fuels for Phase I of the Auto/Oil Air Quality Improvement Research Program (AQIRP). Details of the base stocks and final blend compositions and properties are also included.

Phase I involves the blending and testing of 30 different fuels in four different fuel matrices. The four matrices included gasoline reformulations, methanol fuels, gasoline oxygenate and RVP effects, and gasoline sulfur effects. Specifications for the gasoline fuels were very tight, with several properties being held constant while varying four main fuel properties. Another goal of the blending program was that the gasolines were to be blended from existing refinery streams and not from pure components.

Nine laboratories participated in the certification of the fuels. In the certification process, it was discovered that some of the analytical procedures used in individual labs were subject to interferences, particularly due to oxygenates in the fuels. Some of the methods used to analyze the fuel compositions also seemed inadequate from either a reproducibility or applicability standpoint for potential regulatory and/or legislative initiatives for regulating gasoline or methanol fuel composition for air quality purposes. The findings suggest that modification of existing methods will be required if the necessary precision and accuracy is to be realized. To this end, a program has been initiated to investigate both the suitability of existing fuel analysis methods as well as development of new methods to meet the needs of the program in the future.