Blends of synthetic distillate and biodiesel for low nitrogen oxide emissions from diesel engines

Abstract

This invention shows how to make and use a biodiesel-based fuel in diesel engines without incurring the NOx penalty. Embodiments primarily relate to an optimum range of bulk modulus of compressibility for biodiesel blends, which results in generating “NOx neutral” biodiesel blends or to formulate biodiesel blends with lower NOx emissions than conventional petroleum diesel fuel. These biodiesel blends preferably comprise synthetic paraffinic middle distillate derived from a hydrocarbon synthesis to generate synthetic environmentally-friendly diesel fuels.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This non-provisional application claims the benefit of U.S. Provisional Application No. 60 / 551,574, filed Mar. 9, 2004, which is hereby incorporated by reference in its entiretySTATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] This invention was made with United States Government support under Cooperative Agreement DE-FC26-01NT41098 awarded by the U.S. Department of Energy and entitled “Development & Evaluation of New Processes for the Production of Ultra Clean Fuels from Natural Gas”. The United States Government has certain rights in the invention.BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention relates to the blending of synthetic products derived from synthesis gas and biomass for the production of environmentally-friendly diesel fuels, which generate very low levels of NOx emissions when used in compression ignition engines. [0005] 2. Background of the Invention [0006] A...

AI Technical Summary

Benefits of technology

[0039] Additionally, the invention relates to a method for forming a synthetic diesel fuel formulation comprising primarily of a synthetic distillate and a biofuel within a biofuel volumetric fraction within an optimum range which comprises a bulk modulus of compressibility in said synthetic diesel fuel formulation lower than that of a conventional (crude derived) diesel fuel such that the synthetic diesel fuel formulation generates reduced NOx emissions compared to petroleum diesel fuel formulations.

Problems solved by technology

Aromatics in diesel fuels are also considered undesirable, not only for their adverse effect on ignition quality, but also because they have been implicated in the production of significant amounts of particulates in the engine exhaust.

Many technologies have been developed for reduction of SOx and NOx, but few can remove both types of pollutants simultaneously in a dry process or reliably achieve cost effective levels of reduction.

Such severe hydrotreating imparts relatively little improvement in cetane number and also adversely impacts the fuel's lubricity as discussed in an article by Booth & Wolveridge in Oil &Gas Journal, Aug. 16, 2003, p 71-16.

Even though the low aromatic content of FT diesel yields good thermal stability and reduced tendency to form deposits in engine; the absence of aromatics can result however in swelling of elastomers in vehicle fuel systems, and hence seal leakage problems may arise.

Moreover, the disclosed hydroprocessing schemes for preparing Fischer-Tropsch derived distillates also leave the diesel lacking in one specific property, e.g., lubricity.

Pure biodiesel typically requires special treatment in cold weather, due to a high pour point.

864, that advancing injection timing can lead to an increase in NOx emissions from diesel engines.

Consequently, the problem remains that biodiesel (B100 and B20) increases NOx emissions from diesel engines.

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