Blending of economic, ether free winter gasoline

Abstract

Provided is a novel gasoline composition which is substantially free of ether compounds and is in compliance with a California Predictive Model. The gasoline composition is suitable for use in the winter months, i.e., having a Reid vapor pressure in the range of greater than 7.0 to about 15.0 psi. The method for blending the gasoline comprises blending streams from a refinery in a controlled manner to maintain compliance with the California Predictive Model.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fuels, particularly gasoline fuels which are substantially oxygenate free. More specifically, the present invention relates to a low-emission gasoline fuel which complies with the California Predictive Model, as well as ASTM D4814, and is also substantially free of ether compounds. 2. Brief Description of the Prior Art One of the major environmental problems confronting the United States and other countries is atmospheric pollution caused by the emission of pollutants in the exhaust gases and gasoline vapor emissions from gasoline fueled automobiles. This problem is especially acute in major metropolitan areas where atmospheric conditions and the great number of automobiles result in aggravated conditions. While vehicle emissions have been reduced substantially, air quality still needs improvement. The result has been that regulations have been passed to further reduce such emissions by contro...

AI Technical Summary

Benefits of technology

In accordance with the foregoing objectives, there is provided by the present invention a method of blending a gasoline suitable for use in the winter months, i.e., having a Reid vapor pressure in the range of from greater than 7.00 to about 15.00 psi, which is substantially free of ether compounds. The method comprises blending streams from a refinery, while maintaining the blend substantially free of ethers, in a controlled manner to maintain compliance with the California Predictive Model. It is preferred that testing of the blended fuel occurs during blending for compliance with the California Predictive Model, with adjustments made in the blends based on the results of the testing to thereby maintain compliance with the California Predictive Model.

Among other factors, the present invention is based in part upon the recognition that the blending process of some or all, of the gasoline component streams of an oil refinery, can be controlled, while eliminating ether compounds, to successfully provide by an economic, continuous blending process for a low-emission gasoline substantially free of ether compounds which is in compliance with the California Predictive Model. The difficulty arises in eliminating ether compounds, as a significant difference in blending is required in the absence of ether compounds to achieve the requisite octane rating while also meeting the California Predictive Model specifications. MTBE in particular is a high octane, low-boiling, moderate RVP component and its elimination presents considerable obstacles to successfully blending a gasoline, particularly a high octane gasoline. Yet, it has been discovered that appropriate blending can occur to provide a commercially economic, low-emission gasoline blend suitable for winter using the gasoline-component streams of a refinery. Such blending can also adapt for the subsequent addition of ethanol, where desired. Generally, testing on either a periodic or continuous basis of the blended streams, with subsequent adjustments in the blends based on the results of the testing, is employed in order to maintain compliance with the California Predictive Model. This is particularly preferred as the streams in a refinery can change in composition over time.

In another embodiment, the present invention provides one with a novel, winter gasoline which is substantially free of ether compounds and is in compliance with the California Predictive Model. The compositions are preferably blended by the methods of the present invention, and most preferably contain low amounts of sulfur.

Problems solved by technology

The difficulty arises in eliminating ether compounds, as a significant difference in blending is required in the absence of ether compounds to achieve the requisite octane rating while also meeting the California Predictive Model specifications.

MTBE in particular is a high octane, low-boiling, moderate RVP component and its elimination presents considerable obstacles to successfully blending a gasoline, particularly a high octane gasoline.

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