United States Patent: 4645585

Some of our readers might find the United States Patent, issued to a scientist in the employ of an Australian mining company, we enclose in this dispatch to be of special interest.

It seems to us more of a scholarly thesis on the overall subject of converting Coal into liquid hydrocarbon fuels, rather than a targeted disclosure of one specific way for doing so.

Anyone genuinely interested in the Truths that Coal can be efficiently converted into the complete range of liquid fuels we are now reliant on unreliable petroleum for the supply of, and, that the technology for doing so is, in certain circles, well-known and well-understood, would likely find the full document, and it's references, well worth a close read.

Aside from the Disclosure's rather meticulous founding on, via detailed and credible references, prior art, it also rather authoritatively demonstrates that Coal liquids, whether we obtain them via "indirect" or "direct" Coal liquefaction technologies, can be processed via standard, and long-established, petroleum refining techniques; and, thereby converted into, literally, any type of liquid fuel we now derive from petroleum.

That includes Gasoline, although the focus of this United States-patented, two decades-old Australian technology is primarily on the production, from Coal, of Diesel and Jet Fuel.

And, don't be led into skepticism if you don't recognize the name of the corporate assignee. We assure you that, in both Australian and some international mining circles, they are a big deal, the real thing.

Further, don't be deterred by the initial exposition, which utilizes only chemical names likely unfamiliar to anyone who hasn't done time in the guts of a petroleum refinery.

The following passage, excerpted from the main body of the full Disclosure, telsl us what this is all about:

"The present invention is related to novel fuel blends and particularly jet or diesel fuel blends, and to a method of producing a range of components of such blends from heavy aromatic compounds. In combination, the invention may accordingly provide a new route for the production of specification grade jet and diesel fuel from highly aromatic heavy oils such as those derived from coal pyrolysis and coal hydrogenation."

Comment follows relatively brief further excerpts from:

 

"United States Patent 4,645,585 - Production of Fuels, Particularly Jet and Diesel Fuels

 

Date: February, 1987

 

Inventor: Noam White, Australia

 

Assignee: Broken Hill Proprietary Company, Melbourne

 

Abstract: A first aspect of the invention is concerned with fuels and particularly jet and diesel fuels which comprise blends of substituted mono cyclohexane material and two ring non-fused cyloalkane material. The first material may be n-propylcyclohexane or n-butylcyclohexane. The second material may be nuclear substituted bicyclohexyl and may include cyclohexylbenzene. A second aspect of the invention concerns producing constituents for the fuel from heavy aromatic materials by breaking down the heavy aromatics to naphthas, separating light napthas and other constituents of the fuel before reforming a heavy naptha fraction to provide a BTX fraction which may be treated by hydroalkylation or pyrolysis to provide two ring non-fused cycloalkanes. The product may be enriched by hydrogenation.

(Note: "BTX", as later explained by White, means "benzene, toluene and xylene", all of which are used as Gasoline blending components in standard, conventional petroleum refineries.)

Claims: A method of producing a fuel comprising: hydroprocessing fused polynuclear aromatic compounds to produce a product rich in mononuclear cycloalkanes and mononuclear aromatics comprising a kerosene fraction, a distillate fraction, light gases, light naphtha having a boiling point less than about 65 C., indan, hydrindan, decalin, n-propylcylohexane, n-butylcyclohexane and a naphtha fraction having a boiling range of about 180.-190 C.; converting at least a portion of said product rich in mononuclear cycloalkanes and mononuclear aromatics into two-ring, non-fused cycloalkane compounds; and mixing said two-ring non-fused cycloalkanes with at least one alkylated cycloalkane.

Description: The present invention is related to novel fuel blends and particularly jet or diesel fuel blends, and to a method of producing a range of components of such blends from heavy aromatic compounds. In combination, the invention may accordingly provide a new route for the production of specification grade jet and diesel fuel from highly aromatic heavy oils such as those derived from coal pyrolysis and coal hydrogenation. 

The ready availability of crude mineral petroleum has encouraged its establishment as the basis for fuels in engines of various types, but from time to time concern has arisen for the reliability or availability of the supply of petroleum. This concern has stimulated a search for substitutes. Liquids derived from coal, shale and renewable sources such as plant material have been frequently proposed. Since coal consists predominantly of hydrogen and carbon which are the major constituents of petroleum, it is not surprising that the liquefaction of coal has been a leading contender as a substitute for petroleum. The abundance of coal relative to petroleum and more extensive distribution across the globe have added stimulus to the development of coal liquefaction. 

A very considerable body of literature, expertise and technology has been accumulating in the area of coal liquefaction.

The pyrolysis of coal in various ways, be it by slow cooking, charring or rapid flash heating in the presence of a controlled atmosphere (e.g. pyrolysis in the presence of hydrogen - hydropyrolysis), will produce coal tars and oils of differing quality depending on the conditions employed. These tars and oils could be used as petrochemical feedstocks or as feedstocks for refining into transport fuels which are hereby defined as gasoline, jet fuel and automotive diesel. The current state of the art advocates, in broad terms the fractionation of oil for use as fuels into three major boiling fractions corresponding to a naphtha (destined for gasoline) kerosene (destined for jet fuel) and distillate (destined for automotive diesel). The kerosene and distillate fractions are hydrogenated to convert them to their respective specification grade fuels.

The "cleanliness" of the Fischer-Tropsch product is generally very good. By "cleanliness" is generally meant the absence of nitrogen, sulphur and oxygen compounds in the product. Though the Fischer-Tropsch product is generally free of sulphur and nitrogen, as noted above contamination by oxygenates may call for extra processing of the product prior to sale."

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We close our excerpts here to clarify something: It is noted, immediately above, in confirmation of many of our earlier reports, that Coal liquids derived via Fischer-Tropsch, and related, technology are typically quite "clean" products.

The inventor notes as well, however, that they could suffer from "contamination" by "oxygenates".

Though not specified herein, other authoritative references we have consulted indicate to us that, by "oxygenates", what is meant is alcohols, including Methanol and Ethanol, and a few others; all of which, as we have previously documented, can be reclaimed and used as fuel themselves; or, they can be used as raw materials in the manufacture of useful things like plastics; or, through a variety of available technologies, such as our often-cited  ExxonMobil "MTG"(r), Methanol-to-Gasoline, process, be themselves further converted into Gasoline.

So, if our Coal liquids have to be contaminated with something, "oxygenates" are not bad things for them to be contaminated with. Those alcohols just have to be reclaimed from the Coal liquids, prior to those liquids being passed on to a conventional petroleum refinery for further upgrading, into, as herein, a complete range of liquid hydrocarbon fuels through standard oil refining techniques.

In brief sum, as claimed by Australia, and as confirmed herein by our own US Government:

Anything we now need that is derived from increasingly-scarce and increasingly-expensive petroleum can be made efficiently and cleanly from our still-abundant Coal.


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