United States Patent: 4052292
The Mobil Oil technology we report herein is similar in two respects to quite a few others we have previously brought to your attention.
First, as in our recent dispatch concerning: "United States Patent 4,111,787 - Staged Hydroconversion of an Oil-Coal Mixture", which was issued in September, 1978, to Exxon, Mobil herein utilizes a hydrocarbon oil, which can, we submit, be produced via the destructive distillation of Coal, as in a Coke oven, to dissolve more raw Coal into a liquid product that can then be "hydrotreated", and otherwise upgraded, in rather standard petroleum refining facilities, and made thereby to produce conventional liquid hydrocarbon fuels.
Second, in further confirmation of several of our earlier reports, renewable and Carbon-recycling cellulose can be utilized as a raw material, along with Coal, in such direct liquefaction technologies.
But, since Mobil is intent on making this seem to be a process that requires a large amount of conventional petroleum refinery by-product to make it work, some advance notes are in order.
Although Mobil is careful to repeat that products from various stages of oil refining are to be used, they do specify and identify, deep within their text: "polycyclic aromatic hydrocarbon constituents such as naphthalene, dimethylnaphthalene, anthracene, phenanthrene, fluorene, chrysene, pyrene, perylene, diphenyl, benzothiophene, and their derivatives" as suitable solvents for the dissolution of "coal and wood mixtures".
Additional comment follows excerpts from:
"United States Patent 4,052,292 - Liquefaction of Solid Carbonaceous Materials
Date: October, 1977
Inventor: Wilton Espenscheid, et. al, NJ and PA
Abstract: This invention provides a method for solubilizing wood or wood and coal mixtures in a highly aromatic refinery petroleum solvent to produce homogeneous compositions which have a flowable pitch-like consistency at ambient temperatures. The invention compositions are directly applicable as liquid fuels, or can be further processed into other desirable products.
Claims: A process for liquefaction of solid carbonaceous materials which comprises forming a slurry by admixing comminuted wood and coal with a "petroleum" solvent ... having a boiling point between about 450.degree. F and 1100.degree. F, and heating said slurry at a temperature in the range between about 350.degree. F and 850.degree. F for a period of time sufficient to convert the slurry into a homogeneous composition which has a flowable pitch-like consistency at standard temperature.
A process ... wherein the ratio of wood to coal in the slurry admixture varies in the range between about 0.1 to 10 parts by weight of wood per part of coal.
A process ... wherein the "petroleum" solvent component in the slurry admixture is present in a quantity between about 0.5 and 10 parts by weight ... per part of the combined weight of wood and coal components in the slurry admixture.
Background and Object: It was recognized by early workers that both coal and wood can be liquified by controlled heating in the substantial absence of oxygen. The conversion products are a liquid, gas and a char. ... Pioneer developments in the field are represented by Lurgi and Fischer-Tropsch technology. More recent advances in coal liquefaction are described in U.S. Pat. Nos. 1,904,586; 1,955,041; 1,996,009; 2,091,354; 2,174,184; 2,714,086; 3,375,188; 3,379,638; 3,607,718; 3,640,816; 3,642,608; 3,705,092; 3,849,287; 3,870,621 ... .
The destructive distillation of wood to produce charcoal, oils and gases has been known for centuries. In a recent publication, an American company reported a process for producing as much as two barrels of oil per ton of tree bark by a controlled pyrolysis process. The United States Bureau of Mines, in publication Number 8013 entitled "Conversion of Cellulosic Wastes To Oil", reports 90-99 weight percent conversion of sawdust with 40-60 weight percent yields of oil by reaction with synthesis gas at a temperature of 250 - 425 C and a pressure of 1500-4000 psi, in the presence of water and an inorganic catalyst.
There remains a pressing need for new technology for the conversion of coal and wood into liquid carbonaceous products to complement and to enhance conventional petroleum derived energy and chemical applications. Innovative processes for liquefaction of coal and wood are required which are not dependent on high pressures or reducing gases or catalysts for efficient and economic liquefaction of coal and wood.
It is an object of the present invention to provide an improved method for converting solid carbonaceous materials into gaseous and liquid derivatives having application as fuels and chemical intermediates.
It is another object of the present invention to provide a process for the liquefaction of carbonaceous materials without the use of high pressures, reducing gases, or catalysts.
It is another object of the present invention to solubilize wood and wood/coal mixture to form flowable pitchlike compositions which are directly applicable as liquid fuels."
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Again, the needed solvents, like Anthracene and Naphthalene, as specified by Mobil in the full Disclosure, can be made from Coal. Or - as Mobil does, somewhat surprisingly, reveal within that Disclosure - similar, Coal tar-like liquids can be made via the destructive distillation of Wood; another fact we have previously documented in earlier posts; and, another fact which hints at the Carbon-recycling potentials of a process, based, because of the economies of scale, on Coal, that can produce "compositions which are directly applicable as liquid fuels".