Process for producing coal liquids and use of coal liquids in liquid fuels

Abstract

The present invention provides for the use of coal liquid fuels blended with alcohols such as ethanol, as an alternative to gasoline and other fuels. The coal liquids are obtained by distilling coal tar, or by solvent extraction of coal. A further aspect is a solvent extraction process to create coal liquids to be used as a petroleum substitute. In addition the steps of delayed coking, hydrothermal cracking, hydrodelalkylation, and catalytic cracking and other refining techniques can be used to modify the aromatic coal liquids, making them more aliphatic and hence more similar to petroleum. A preferred embodiment of the coal liquid gasoline substitute is comprised of 85% ethanol and 15% coal-derived counterparts. It is a further object of the present invention to provide a method of solvent extraction for coal liquids to be processed for use as a petroleum replacement

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to provisional application No. 60 / 841,624 filed on Aug. 31, 2006.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX [0003] Not Applicable BACKGROUND OF THE INVENTION [0004] 1. Field of Invention [0005] This invention relates to a method of obtaining and refining coal liquids and incorporating them in transportation fuels that also contain alcohols. [0006] 2. Description of the Prior Art [0007] Ethanol is used as a transportation fuel worldwide, often as a substitute for gasoline. In the US, a number of processes have been used to create ethanol. The main sources have been the fermentation of agricultural products such as corn, switchgrass, etc. However, ethanol is generally not compatible with certain polymeric seal materials, due to the low content of aromatic liquids. [0008] Co...

AI Technical Summary

Benefits of technology

[0014] A further aspect of the present invention is the blending of coal liquids in alcohol to create a motor fuel with a high octane rating. The coal liquids are highly soluble in alcohol and the combustion efficiency of ethanol enhances combustion of the coal liquids and thus minimizes the emission of aromatic partially-combusted hydrocarbons in the exhaust.

Problems solved by technology

However, ethanol is generally not compatible with certain polymeric seal materials, due to the low content of aromatic liquids.

Coal derived fuels are of interest due to the possible future lack of availability of petroleum products, and the rising cost of petroleum on world markets.

However, coal derived liquids are generally too aromatic and have slow kinetics resulting in significant pollution.

Furthermore, aromatic coal liquids often are poorly soluble in gasoline and become tarry in the presence of gasoline.

However, the lack of aromaticity of alcohol results in compatibility problems with polymer seals.

Another issue is that alcohols have a lower energy density (i.e., joules per kg) than gasoline.

Generally, however, alcohols are more expensive than liquids derived from petroleum or coal.

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