Allied Chemical Liquefies Coal with CO & H2S

United States Patent: 4235699

 

Yesterday, we sent you information concerning: "US Patent 2,128,262 - Carbon monoxide manufacture"; which was issued and assigned, in 1938, to New York's then Semet-Solvay Engineering Corporation.

The patent discloses, as they put it: "a technology for an efficient and economical process for the manufacture of carbon monoxide of high purity by the reduction of carbon dioxide".

Their process entails, in it's essence, passing CO2, from whatever source, over and through red-hot Coal, a concept that should not, presuming you to have followed our posts, be unfamiliar to you; and, thereby, generating what we would presume to be, if wanted, rather prodigious quantities of Carbon Monoxide.

We included in that report information concerning work later performed by US Bureau of Mines scientists, operating in Pittsburgh, PA, who had developed a method for "The Hydrogenation of Coal with Carbon Monoxide and Water", with the intent being to prepare "an oil which could then be converted to more volatile fuels by known hydrocracking techniques" via reactions between Coal, Water and Carbon Monoxide.

We also explained how the Semet-Solvay company, who, as in the example of US Patent 2,128,262, were an early originator of technology for reacting Carbon Dioxide with hot Coal to make Carbon Monoxide, had actually, by the time that patent was issued, been acquired by Allied Chemical.

Herein, we see that Allied continued the Semet-Solvay work; extending it's scope, actually.

Allied Chemical devised a process wherein Carbon Monoxide, as can be produced by passing Carbon Dioxide over hot Coal, could, in emulation of the work performed in Pittsburgh by the USBM, be used to liquefy Coal.

And, in their process, Allied uses another compound, Hydrogen Sulfide, which can as well be generated as a by-product from the use of some Coals; and, which, again as in earlier of our reports, can used to make it unnecessary to obtain and to utilize expensive elemental Hydrogen in the hydrogenation reactions.

There is, in fact, an interesting take on that, relative to what we know of West Virginia University's "West Virginia Process" for the direct liquefaction of Coal.

As we further explain, in comment following excerpts from the above link to:

"United States Patent 4,235,699 - Solubilization of Coal with Hydrogen Sulfide and Carbon Monoxide

 

Date: November, 1980

 

Inventor: Charles Ratcliffe, et. al.

 

Assignee: Allied Chemical Corporation, NJ

 

Abstract: Conversion of coal to products soluble in common solvents and conversion of coal tar to products of lower molecular weight, effected in liquid or fused reaction medium using a hydrogenating reactant, are carried out employing hydrogen sulfide and carbon monoxide as the sole or major hydrogenating reactant, without need of elemental hydrogen or a hydrogen donor solvent.

Claims: (A) process for conversion, in liquid or fused reaction medium using a hydrogenating reactant, of a substrate of the group consisting of coal and coal tar and mixtures thereof to products of lower molecular weight than the starting material and soluble in ethyl acetate: the improvement which comprises employing as the sole hydrogenating reactant, such reactant consisting essentially of hydrogen sulfide and carbon monoxide.

(And) wherein the substrate is coal tar. 

(And) wherein the substrate is coal ... (and/or) high volatile bituminous coal ... .

Background: This invention relates to the conversion of coal and/or coal tar to products of lower molecular weight than the starting material and soluble in solvents such as ethyl acetate, benzene and other common solvents. 

It is generally known in the coal liquefaction art, to mix pulverized coal with a hydrogen donor solvent, such as a fraction of recycled oil produced in the process, and with a catalyst if desired and then heat ... under a hydrogen pressure ... . The obvious disadvantage of such processes is the requirement of expensive hydrogen needed to hydrogenate the coal and to rehydrogenate the hydrogen donor solvent. It would be desirable to provide a method to hydrogenate and thus solubilize coal without use of elemental hydrogen either directly in the process, or for rehydrogenating a hydrogen donor solvent.

Summary: In accordance with this invention, the solubilization of coal and conversion of coal tar to products of lower molecular weight, effected in liquid or fused reaction medium using a hydrogenation reactant, are carried out employing reactant consisting essentially of hydrogen sulfide and carbon monoxide as the sole or major hydrogenating reactant, without need of elemental hydrogen or a hydrogen donor solvent.

In particular, when using H2S/CO as hydrogenating agent in accordance with this invention, materials which can be used as the reaction medium are nonhydrogen donor diluents as known in the art, especially such compounds as aromatic hydrocarbons including alkylbenzenes, alkylnaphthalenes, alkylated polycyclic aromatics, heteroaromatics, and mixtures thereof and streams such as unhydrogenated creosote oil.

Hydrogen donor diluents can also be used, for example partially hydrogenated cyclic hydrocarbons such as tetrahydronaphthalene .... . Tetrahydronaphthalenes and anthracene oil are particularly good hydrogen donor diluents which can be used as the reaction medium, mixed or not with nonhydrogen donor diluents in the process of this invention. The only requirement of the reaction medium is that it serve as a liquid dispersing medium of hydrogen sulfide and carbon monoxide reactants for contact with the coal or coal tar without decomposing the reactants and that it be itself essentially stable against cracking under the reaction conditions.

Specifically, conversion of lignite, subbituminous coal and high volatile bituminous coal to products soluble in ethyl acetate is accomplished by using a hydrogenating agent which consists essentially of hydrogen sulfide and carbon monoxide."

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So, in order to hydrogenate and liquefy all kinds of Coal, we don't need either elemental Hydrogen or exotic Hydrogen-donor solvents - just Coal and some Coal tar, and, Hydrogen Sulfide and Carbon Monoxide.

Note, though, that Hydrogen donor solvents, made from primary and long-known Coal tars, can, if wanted, be used in the process. Allied mentions specifically "tetrahydronaphthalene .... and anthracene oil", for instance; and, we remind you that such "tetrahydronaphthalene", derived from the better-known Naphthalene, is, we have been led by other sources to believe, also known as "Tetralin", and is the Hydrogen-donor solvent specified by WVU, in their "West Virginia Process" for direct Coal liquefaction.

Plain old "creosote", in fact, as above, again in confirmation of earlier of our reports, can also be utilized.

Otherwise, Hydrogen Sulfide shouldn't be too hard for us to get - especially since our vital Coal-use industries are sometimes accused of inadvertently making too much of it already.

Carbon Monoxide, again, we can make in any quantity we might want, simply by passing Carbon Dioxide over and through red-hot Coal.

And, by combining all of those ingredients, we can completely convert "coal and/or coal tar to products of lower molecular weight ... soluble in ... benzene".


And, we assure you: Once we have organic compounds, from any source, dissolved in benzene, the solution can be further processed, via fairly standard petroleum refining techniques, the "known hydrocracking techniques" specified, as noted above, by Pittsburgh USBM researchers, and converted thereby into traditional motor vehicle liquid fuels.