We have many times referenced operation of the factory in Kingsport, TN, where Eastman Chemical Company is profitably making the liquid fuel and, as in ExxonMobil's "MTG"(r) technology, Gasoline raw material, Methanol, out of Coal.
We have also documented, from a variety of sources, that, if the Hydrogen content of synthesis gas derived from Coal needs to be supplemented, in order to make such syngas amenable to more complete catalytic conversion into liquid hydrocarbons, such supplementation can be effected by the rather simple expedient of adding Steam, in appropriate ways, to the reaction mix.
Herein, Eastman Chemical and, via the Patent Office, our own US Government provide further confirmation of that fact.
Comment, wherein we emphasize some other significant facts, follows excerpts from the above link to:
"United States Patent 7,503,947 - Process for Humidifying Synthesis Gas
Date: March, 2009
Inventor: Scott Barnicki, TN
Assignee: Eastman Chemical Company, TN
Abstract: Disclosed is a process for humidifying syngas to achieve a water to carbon monoxide molar ratio in the product syngas within a desired range and in which the molar ratio which can be varied over time in response to changes in downstream syngas requirements. The raw syngas is produced by reacting a carbonaceous material with oxygen, water, or carbon dioxide and can be combined with a diluent to produce a diluted syngas stream which can be cooled and contacted with liquid water to give a humidified syngas. The H2O:CO molar ratio of the humidified syngas may be adjusted in response to time-varying downstream syngas requirements by changing the amount and/or temperature of the diluent that is combined with the raw syngas stream, by adjusting quench and heat exchange conditions, or a combination thereof. The application of the process to the coproduction of chemicals and power are also disclosed.
Claims: A process for the coproduction of power and chemicals, comprising: (a) reacting a carbonaceous material with an oxidant stream in a gasifier to produce a raw syngas stream comprising hydrogen, carbon monoxide, and carbon dioxide; (b) combining said raw syngas stream of step (a) with a diluent to produce a diluted syngas stream comprising about 10 to about 60 moles of said diluent per 100 moles of said raw syngas stream; (c) passing said diluted syngas stream of step (b) to a radiant heat exchanger to produce a cooled syngas stream; (d) contacting said cooled syngas stream of step (c) with liquid water to produce a humidified syngas stream; (e) passing said humidified syngas stream to a water-gas shift reactor to produce a shifted syngas stream comprising additional hydrogen and carbon dioxide during a period of off-peak power demand; (f) passing said shifted syngas stream from step (e) to a chemical process to produce a chemical product; and (g) passing said humidified syngas stream from step (d) to a power producing process to produce electricity during a period of peak power demand; wherein the amount of said diluent combined with said raw syngas stream in step(b) is chosen to give an H2O:CO molar ratio of about 1:1 to about 3:1 in said humidified syngas stream of step (d) and said H2:CO molar ratio varies in response to a downstream syngas requirement.
The process ... wherein said H2O:CO molar ratio ... is chosen in response to a syngas feedstock requirement for said water gas shift reactor, a fuel requirement for said power producing process, or a combination thereof.
The process ... wherein said diluent ... comprises water, methane, ethane, propane, butane, recycled syngas, .... carbon dioxide, waste gases, combustion stack gases, or combinations thereof.
The process ... wherein said carbonaceous material comprises coal.
The process ... wherein up to 100 volume percent of said shifted syngas stream ... (is reacted) in a fixed bed methanol reactor (or) a liquid slurry phase methanol reactor."
-----------
Aside from the fact that the composition of the Coal syngas can be adjusted by changing the "H2O" to "CO molar ratio" in order to vary the "H2:CO molar ratio" which then "varies in response to a downstream syngas requirement", which we take to mean that the syngas can be varied in composition depending upon what specific hydrocarbons you wanted to synthesize out of it, note, as in: "raw syngas is produced by reacting a carbonaceous material with oxygen, water, or carbon dioxide", that, in confirmation of other references we have cited, Carbon Dioxide can be utilized, and thus recycled, along with, or instead of, Steam, as one gasification reactant for raw Coal, to produce a synthesis gas of specific and useful composition.
Note, as well, that, not only can Carbon Dioxide be utilized, but, again in confirmation of other references we have cited, as in, above: "application of the process to the coproduction of chemicals and power are also disclosed", not only can we produce the liquid fuel, and Gasoline raw material, Methanol, from Coal, we can, as highlighted in: "passing said humidified syngas stream ... to a power producing process to produce electricity during a period of peak power demand"; at the same time, and in the same facility, co-generate some useful amounts of electricity along with that nearly-precious Methanol.
And, finally, not only can Carbon Dioxide, which we might otherwise be compelled by law to stuff down a leaky old oil well in some desolate wasteland, such as West Texas, be utilized in a process that transforms Coal into Methanol, it can be utilized as it comes raw, in the form of "waste gases" and "combustion stack gases", as it is generated, for one instance, in rather astonishing quantities, as we've previously documented, by the complete industrial process of manufacturing "green" Ethanol from Corn.