United States Patent: 4101416


As with many of our earlier reports, it is seen herein that, not only can primary and long-known Coal tars, as can be generated in Coke ovens, be hydrogenated via long-established petroleum refining techniques, processes that are well-known in that industry, but, once the Coal tars are thus hydrogenated, they can be made to serve as the agents of dissolution, liquefaction and hydrogenation for more Coal.

As confirmed by our United States Government, both by their issuance, and by their sponsorship, of:

"United States Patent 4,101,416 - Process for Hydrogenation of Hydrocarbon Tars


Date: June, 1978


Inventor: Geoffrey Dolbear, CA


Assignee: Occidental Petroleum Corporation, Los Angeles


Abstract: Hydrocarbon tars of high asphaltene content such as tars obtained from pyrolysis of coal are dissolved in a solvent formed from the hydrogenation of the coal tars, and the resultant mixture hydrogenated in the presence of a catalyst ... to form a light hydrocarbon as a solvent for the tars. Hydrogen content is at least three times the amount of hydrogen consumed.

The government has rights in or in respect of this invention pursuant to Contract N. E(49-18)-2244 awarded by the United States Energy Research and Development Administration.

Claims: A process for hydrogenation of hydrocarbon tars of high asphaltene content (and the formation) of  additional aromatic hydrocarbon solvent for the tars ... (and) ... recovering at least a portion of the aromatic hydrocarbon solvent formed during the hydrogenation from the effluent of the hydrogenation zone and using the recovered aromatic hydrocarbon solvent in preparing the solution of hydrocarbon tar for feed to the hydrogenation zone.

A process for hydrogenation of hydrocarbon tars resulting from the coal pyrolysis (by) generating a hydrocarbon tar containing ... asphaltenes from pyrolysis of coal; (and) forming a liquid solution as a hydrocarbon tar in an aromatic hydrocarbon solvent for the tar, said aromatic hydrocarbon solvent ... being formed as a product during the hydrogenation of the hydrocarbon tar ... .

Background: The present invention relates to the hydrotreatment of tars derived from the pyrolysis of coals to saturate and reduce the molecular weight of the tar constituents while removing bound sulfur, nitrogen and oxygen. Coal tars formed from pyrolysis and other thermal decomposition techniques can be upgraded ... .

Summary: In accordance with the present invention, hydrocarbon tars ...  as derived from thermal pyrolysis of coal are hydrogenated by dissolving the tars in a hydrocarbon solvent product of hydrogenation, subjecting the fluid mixture to catalytic, substantially liquid phase hydrogenation ... .

This yields a product which includes generated hydrocarbon solvent for the hydrocarbon tars ... .

(The)  nature of the gross product produced may vary widely depending upon the degree of hydrogenation carried out. In any instance, however, the liquid hydrocarbon solvent formed will be highly aromatic in nature.

At low hydrogen concentrations and mild hydrogenation conditions, the process may be employed mainly to reduce the bound nitrogen, oxygen and sulfur content of the hydrocarbons with some production of the lower boiling paraffinic hydrocarbons. Under severe conditions, a high degree of molecular weight reduction occurs favoring the production of lower boiling aromatic hydrocarbons which serve as part of the hydrocarbon solvent for the tars.

(The) constituents of the solvent can serve as hydrogen donors which provide hydrogen which, in the presence of the catalyst, terminates the free radicals which may develop during breakdown of the heavy hydrocarbons. Tetralin, for example, and similar saturated and partially saturated molecules in the hydrocarbon solvent have been established as hydrogen donors which reduce the severity of operating conditions to achieve a desired degree of hydrogenation ... in a chain of sequential hydrogen exchange reactions. 

As will be appreciated, hydrogenation may be carried out stagewise in a plurality of hydrogenation zones in series. Hydrogen in this instance may be fed to the first and any or all of the hydrogenation zones in the series."



First, some free Hydrogen is required herein for the hydrogenation of the Coal tars; which, as we've documented, is no sweat for established petroleum refiners to produce. Many of them already generate it on a routine basis for the needed upgrading of natural heavy crude oils.

Second, note, once again, specified use of the Hydrogen-donor solvent "Tetralin" - an hydrogenated version of the primary Coal oil, Naphthalene, which is, as we've many times documented, the Hydrogen-donor solvent specified by WVU, in their "West Virginia Process" for direct Coal liquefaction.

Finally, we have herein, yet again, more evidence, as in the statement: "The government has rights in or in respect of this invention pursuant to Contract N. E(49-18)-2244 awarded by the United States Energy Research and Development Administration".

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