In further confirmation of earlier reports we've made, German scientists, as herein affirmed by our United States Government, have demonstrated that hot Coal can be reacted with both reclaimed Carbon Dioxide and Steam, and made thereby to generate a mixture of Carbon Monoxide and Hydrogen; a synthesis gas that can then be catalytically condensed, via, for instance, the Fischer-Tropsch technology, into liquid hydrocarbons.
Note, too, that, among many other carbonaceous/hydrocarbon compounds, Methane, as can be synthesized, via the Sabatier process, from Carbon Dioxide, or, via Steam-gasification, from Coal, can also be added to the mix of raw materials.
And, apparently, and perhaps most importantly, both the uncondensed hydrocarbon off-gases and, even, some of the lower-value liquids produced from a Fischer-Tropsch reactor, including Methanol, can be "dumped" into the gasifier along with Coal and the other compounds, to be reacted together and generate even more hydrocarbon synthesis gas.
This is, thus, in one, perhaps the major, aspect, actually a technology for enhancing the productivity and efficiency of hydrocarbon production, from Coal, via the Fischer-Tropsch catalysis of synthesis gas, since those lower-value Fischer-Tropsch products are separated from the more desired hydrocarbons and recycled back into the synthesis gas generator, to incease the production of hydrocarbon synthesis gas, and to improve the quality of that syngas, which is generated primarily from Coal.
Not only that, but such internal recycling improves the energy efficiency of the total process.
An advance excerpt helps to summarize those points:
"The Fischer-Tropsch synthesis ... plant consists of a synthesis gas production unit, the actual Fischer-Tropsch synthesis and the stage for processing the products. The ... total yield of value products and the thermal efficiency can be markedly improved when ... the undesired low boiling by-products of the synthesis, e.g., methane as well as C2 -- and part of the C3 hydrocarbons, are recycled with water and/or carbon dioxide to the mixing and separation zone of the gasifier where they are converted via an endothermic reaction to carbon monoxide and hydrogen. While the thermal efficiency of the combined coal gasification, synthesis and final processing steps (including the energy requirements of the conventional process), i.e., without recycling the Fischer-Tropsch by-products, amounts to roughly 44%, the thermal efficiency of the process of the invention increases to roughly 52% on recycling the by-products. There is a similar situation with (other) by-products of the Fischer-Tropsch synthesis, in particular with lower aldehydes and alcohols."
Brief comment follows further excerpts from:
"United States Patent 4,430,096 - Production of Gas Mixtures Containing Hydrogen and Carbon Monoxide
Date: February, 1984
Inventor: Friedrich Schnur, et. al., Germany
Assignee: Ruhrchemie Aktiengesellschaft
Abstract: An improved process for the production of a gas mixture containing hydrogen and carbon monoxide by endothermal partial oxidization of an organic compound with steam and/or carbon dioxide is disclosed wherein at least a portion of the heat required for the partial oxidation is obtained by direct heat exchange with products obtained from the gasification of a carbonaceous ash-forming fuel with oxygen in the presence of steam.
Claims: A process for the production of gas mixtures containing hydrogen and carbon monoxide which comprises: gasifying an ash-forming solid carbonaceous fuel with oxygen or an oxygen containing gas mixture in the presence of steam ...; and ... feeding (all the) products ... to a vessel into which a partially oxidizable organic compound is fed together with steam and/or carbon dioxide and therein contacting the gaseous effluent and liquid ash with steam and/or carbon dioxide introduced with said organic compound (and thereby) cracking of the organic compound ... .
(And) wherein the carbonaceous ash-forming fuel is finely divided coal.
(And) wherein the organic compound is obtained by the Fischer-Tropsch synthesis ... .
(And) wherein said organic compound is selected from the group consisting of methane (et. al.)
(And) wherein said organic compound is selected from the group consisting of methanol, ethanol (et. al.)
(And) wherein said organic compound is fed together with carbon dioxide into said vessel.
Background and Field: This invention relates to the production of gas mixtures containing hydrogen and carbon monoxide by ... (cracking) ... organic compounds with steam and/or carbon dioxide ... .
This invention is (also) concerned with the recovery of heat from the gasification of carbonaceous fuels in the formation of carbon monoxide and hydrogen to supply heat for the endothermal partial oxidation of organic compounds.
Summary: The objects of this invention are (to provide) an improved process for the production of a gas mixture containing hydrogen and carbon monoxide ... the improvement residing in that at least a portion of the heat required for said partial oxidation is obtained by direct heat exchange with the products obtained from the gasification of a carbonaceous ash-forming fuel with oxygen or an oxygen containing gas mixture in the presence of steam.
As a result of the process, carbon monoxide and hydrogen are produced (and) waste products from chemical sythesis can be employed as the organic compound to be endothermally partially oxidized. By the process of the invention, large quantities of hydrogen and carbon monoxide are formed in a process which maximally utilizes heat which is supplied and/or developed.
The following carbonaceous, ash-forming fuels are particularly suitable as feedstock for the process according to the invention--hard coal, lignite, solid and liquid carbon-containing residues, e.g., residues from the coal hydrogenation ... .
The following carbonaceous, ash-forming fuels are particularly suitable as feedstock for the process according to the invention--hard coal, lignite, solid and liquid carbon-containing residues, e.g., residues from the coal hydrogenation ... .
It is particularly worth mentioning that (the process allows) the use of carbon dioxide ... ."
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Yes, we would agree, that is "particularly worth mentioning".
The full Disclosure is lengthy, detailed and complex; and, we have reproduced, above, only the facts most pertinent to our thesis:
Coal can be gasified with Steam and with added Carbon Dioxide in order to produce an hydrogenated synthesis gas well-suited for catalytic condensation via, for instance, the Fischer-Tropsch synthesis, into liquid hydrocarbon fuels.
And, some segments of the overall process generate heat energy which can be reclaimed and used to help drive other, endothermic, segments of the process.
Methane, as can be synthesized, via the Sabatier process, as now being further developed, as we've documented, by NASA, from Carbon Dioxide, can be added to the mix of raw materials.
Ethanol, the darling of our agricultural lobby, can also be added.
By-products of the Fischer-Tropsch hydrocarbon synthesis of liquid hydrocarbon fuels, for which end-use the products of this invention are intended, can be recycled back into the system, along with the Coal, the Steam, and the Carbon Dioxide, to generate even more hydrocarbon synthesis gas.
All in all, this German invention describes a thorough and efficient, albeit complex, process, that, though based on Coal, allows the inclusion of multiple Carbon-recycling raw materials, including Carbon Dioxide itself, and generates a product gas ideally suited for catalytic condensation into liquid hydrocarbons.
It is complex, but:
Is it so complex that it isn't worth the effort for us residents of US Coal Country to puzzle it all out, and to begin using it, to, efficiently, convert our abundant Coal and our waste streams of Carbon Dioxide into useful and, almost desperately it would seem, needed, hydrocarbon products?