Gasification of carbonaceous solids
Not long ago, we again confirmed that the petroleum industry and, by extension, through issuance of a United States Patent confirming the technology, our own United States Government know full-well that, not only can Coal be converted, through the initial generation of synthesis gas, into hydrocarbons; but, so can, right along with Coal, sustainable and CO2-recycling botanical materials.
We believe our most recent dispatch documenting that fact is accessible on the West Virginia Coal Association's web site via the link:
Exxon Co-Gasifies Coal and Carbon-Recycling Biomass | Research & Development; wherein is reported: "United States Patent Application 20100083575 - Co-gasification Process for Hydrocarbon Solids and Biomass; 2010; ExxonMobil Research and Engineering Company; A process for the co-gasification of carbonaceous solids (coal) and biomass ... wherein the solid carbonaceous particles comprise coal (and)wherein the biomass comprises biological matter selected from wood, plant matter, municipal waste, green waste, byproducts of farming or food processing waste, sewage sludge, black liquor from wood pulp, and algae."
The purpose of such gasification, of course, is to form a "synthesis gas" suitable for catalytic chemical condensation into gaseous and liquid hydrocarbons; direct substitutes, that is, for anything we now import from OPEC.
We see Coal as being currently crucial to such processes, due to it's abundance and established production and delivery infrastructure.
However, the inclusion of renewable "biomass", with Coal, as a portion of the raw material feed, would enable a certain amount of sustainability and, through natural photosynthesis, Carbon Dioxide recycling.
Further, it would help us to conserve and extend our vital Coal resources, for use in these Carbon conversion processes, and for conventional, critical electric power generation purposes, well into the future.
Herein, in confirmation of another of our earlier reports, as accessible via:
Standard Oil 1953 Syngas from Coal, CO2 and Cellulose | Research & Development;concerning, primarily:
United States Patent 2,644,745 - Production of Gases from Carbonaceous Solids; July, 1953; Assignee: Standard Oil Development Company; Abstract: The present invention relates to the conversion of carbonaceous solids into combustible gases.More specifically, the invention is concerned with the gasification of all types of coal (and) cellulosic materials ... to produce ... gas mixtures containing CO and H2 suitable for the catalytic synthesis of hydrocarbon and oxygenated compounds. (One) object of my invention is to provide an improved process for the continuous gasification of carbonaceous solids ... and with full utilization of available carbon."
we again see, now unsurprisingly, that such Coal-based, indirectly CO2-recycling hydrocarbon conversion and synthesis technology was a subject of rather intensive development more than one half of a century ago. And, that the extraordinary potentials had been recognized and acknowledged back then more than once, by, essentially, the same organizations that developed and then certified the technology disclosed by "United States Patent 2,644,745", and confirmed them again quite recently, through publication of "United States Patent Application 20100083575".
Comment follows, and is inserted within, excerpts from the initial link in this dispatch to:
"United States Patent 2,633,416 - Gasification of Carbonaceous Solids
Date: March, 1953
Inventor: Edward Gornowski and Karl Nelson, NJ
Assignee: Standard Oil Development Company
Abstract: The present invention relates to the production of gases from non-gaseous carbonaceous materials and, more particularly, to the production of gas mixtures containing carbon monoxide and hydrogen ... from such solid carbonaceous materials as ... various coals (and) cellulosic materials.
It has long been known that solid fuel materials, such as coal ... may be converted into more valuable gases which can be more efficiently handled and more efficiently used for a greater variety of purposes.
One of the most widely practiced gas generating conversions is the so-called water gas process in which solid fuels, such as coal or coke (i.e., "carbon") of any origin, are reacted with steam ... to produce water gas mixtures of carbon monoxide and hydrogen in varying proportions, depending mainly on the time of contact, conversion temperatures and the feed ratio of steam.
The water gas process permits the production of gas mixtures of widely varying compositions and (the) process ... is extremely well suited ... for the production of gases for hydrogenation processes and particularly for the catalytic synthesis of hydrocarbons and/or oxygenated organic compounds ... depending on the products desired.
(As in other of our reports concerning similar and related Coal conversion technologies, the composition of the synthesis gas can be "tailored", so to speak, to enable the production of either "hydrocarbons" or "oxygenated organic compounds", i.e., alcohols, such as Ethanol and Methanol.)
In accordance with the present invention, the carbonaceous solids to be gasified are dried and preheated in direct heat exchange with hot gases produced in the gasification stage and flowing upwardly through two or more fluidized beds of solids to which the solid feed is supplied countercurrently to the gases which serve simultaneously as heating and fluidizing medium.
The arrangement of a plurality of fluidized preheating beds or zones in combination with the countercurrent flow of solids and gases permits the utilization of waste heat of the product gases ... in an order affording the greatest heat transfer efficiency and maximum heat recovery.
For example, the temperature in the preheating bed first contacted by the product gases may be maintained just below the level of beginning carbonization, while the temperature in the preheating bed last contacted by the product gases should be kept substantially above the dew point of the product gases. By this arrangement, maximum heat is recovered from the product gases and maximum preheat is transferred to the solids entering the gas generator.
(We've earlier documented closely-related techniques for the recycling of heat in a Coal conversion process, either to enable a needed endothermic chemical reaction to be driven by the heat from an exothermic reaction; or, to utilize exothermic reaction heat to power other processes. An example can be seen in the very, very closely-related technology disclosed in our report of:
Esso 1956 Self-powered Coal + Steam = Hydrogenated Syngas | Research & Development; concerning:
"United States Patent 2,741,549 - Conversion of Carbonaceous Solids into Volatile Products; 1956; Esso Research and Engineering Company; Abstract: The present invention relates to the conversion of carbonaceous materials including solids such as all types of coal ... into volatile products such as light oils (and) gasses containing CO and H2 ... . The present invention relates to the treatment by means of hydrogen or gasses containing pr yielding hydrogen, of carbonaceous materials, particularly materials containing sulfur ... into valuable products which are usually liquid ... . The ... water gas reaction (which generates Hydrogen.) take(s) place between the steam and the carbon ... . ... Water gas ... is withdrawn ... to be passed ... to any suitable use as a fuel gas (or) for hydrocarbon synthesis";
wherein heat arising from one reaction is directed to another reaction in the Coal conversion sequence that requires heat to be driven forward. In other of our reports concerning such potentials, the processes have been labeled "auto-thermal", meaning that no external supply of energy is required, since the energy derived internally, both from the partial oxidation of Carbon and the catalytic chemical condensation of syngas into hydrocarbons, is sufficient to power the entire system of manufacturing hydrocarbons from Coal.)
Carbon losses are avoided by feeding the high carbon gasification residue directly to a combustion zone wherein their sensible and potential heat content is converted into steam.
(We apologize for what will be an unfortunately lengthy and distracting interruption, and sidebar discussion, but, we are compelled to summarize here, and comment on, the details of the complicated full Disclosure:
Basically, they further oxidize any solid Carbon remaining in the gasification residues, and, the heat from that combustion, in addition to heat supplied by the initial gasification, is sufficient to generate both the Steam needed for that initial Coal "hydro" gasification and to conduct any preheating or pretreatment, as they specify, of the raw material feed.
We've elsewhere documented, as in:
Spain Reprocesses US CoalTL Residue | Research & Development; concerning: "Gasification of COED chars in a Koppers--Totzek gasifier. Final report; 1978; Abstract: In December 1974, EPRI entered into a contract with the FMC Corporation to demonstrate COED char gasification in a commercial Koppers--Totzek gasifier. The chars were shipped to Spain in early 1975 and the gasification tests conducted at the ENFERSA plant in Puentes de Garcia Rodriguez, Spain in August 1975. The results of these tests on the two chars demonstrated that COED char could be gasified in the Koppers--Totzek gasifiers. The useful gas yield was about 45 MSCF of carbon monoxide plus hydrogen gas per ton of char. The carbon conversion of the char to gas was 85 to 90%";
that, any still-carbonaceous residues left by an initial Coal gasification process could, on the other hand, themselves be further gasified, and made to yield even more hydrocarbon synthesis gas.
Further, Coal gasification technology has become so sophisticated, that, referring back to our citation of "United States Patent 2,644,745 - Production of Gases from Carbonaceous Solids", the various reactions can be structured so as to ensure the "full utilization of available carbon", with, thus, little or no such carbonaceous residues actually being left to justify or require further treatment.
That is not precisely the case with our subject herein; but, there are other considerations made, as we will further discuss.
We'll also note, without reproducing the details, that Standard Oil, in the full Disclosure of United States Patent 2,633,416, does go on in commendable detail, even providing tables for illustration, about the relative percentages of starting materials, i.e., Coal, H2O and Oxygen, to supply to the initial gasification, to ensure both as complete a utilization of the available Carbon as possible, and, the production of synthesis gases composed of specifically-desired relative contents of Hydrogen and Carbon Monoxide.
However, they do stipulate, as well, that some of the Carbon does, or can be made to, pass through into the gasification residues. That residual Carbon is then to be fully oxidized, in a boiler, to provide Steam for the initial Coal gasification, and to ensure the supply of sufficient heat energy for the total process.
Standard Oil summarizes that the gasification reaction can be structured so that up to 95% of the Carbon is converted, with up to 80% of the Steam, into the desired Carbon Monoxide and Hydrogen synthesis gas. Conversely, if more heat energy needs to be generated within the system, 10%, and even up to 50%, of the original Carbon can be allowed to pass through the gasification stage unconverted, and then be combusted to provide the heat, but, with the concurrent production of CO2 that would not be added to the syngas and would thus go unutilized and unconsumed.
There is, thus, some CO2 in addition to up to, roughly, as we read it, a CO2 content of 10% of the total initial syngas product, that is co-produced.
The CO2 in the syngas itself not released or emitted. In the syngas catalysis, or hydrocarbon synthesis stage, it seems to be reacted, with the surplus of Hydrogen, in a Sabatier-type sub-process, and thus made to form Methane, as a co-product, with liquid hydrocarbons, of that hydrocarbon synthesis.
We submit that the by-product Methane, CH4, could be reacted with some of the effluent CO2 from the secondary, heat-producing combustion stage, and with some of the process Steam that's being purposely generated, and be made to form, as seen in:
Texaco 1948 CO2 + CH4 = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 2,448,290 - Process for the Production of Synthesis Gas; 1948; The Texas Company, NYC; This invention relates to a continuous method of manufacturing water gas involving the reaction of a gaseous hydrocarbon with carbon dioxide and steam so as to produce carbon monoxide and hydrogen";
even more of the Carbon Monoxide and Hydrogen synthesis gas blend.
And, any excess CO2 not, as above, reformed with the by-product CH4, Methane, could, as seen in:
Texaco 1951 Coal + CO2 + H2O + O2 = Syngas | Research & Development; concerning: "United States Patent 2,558,746 - Carbon Monoxide and Other Gases from Carbonaceous Materials; 1951; The Texas Company, NYC; This invention relates to a process and apparatus for the generation of gases comprising carbon monoxide ... and hydrogen, suitable as a feed for the synthesis of hydrocarbons, from powdered coal (wherein) carbon dioxide ... reacts with the carbon to produce carbon monoxide";
then be collected and directed back into the initial Coal gasification, where it would react with the hot Carbon and thereby form more of the desired Carbon Monoxide.
And, keep in mind that it isn't just Coal that's being gasified, but, along with the Coal, a certain amount, as stipulated herein by Standard Oil, of naturally CO2-recycling "cellulosic materials".
It all stands as testament to how thorough and complete our knowledge of Coal conversion science, in certain circles, had become more than half a century ago, not that long after Germany's and Japan's successful WWII Coal-based synfuel technologies had been "acquired" by the US and its allies.)
Claims: (A) process of producing gas mixtures containing CO and H2 from solid carbonaceous materials and an oxidizing gas containing steam (and, wherein) the heat required by (the) gasification process is supplied by combustion of a portion of (the) carbonaceous solids and direct heat exchange of burned solids and solids undergoing said gasification (and combusting residues in a) combustion zone (to generate) steam.
The process ... in which said oxidizing gas comprises free oxygen (and wherein) steam is contacted (with the carbonaceous materials) in a gasification zone ... .
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We'll close our excerpts there so that we can make note of the fact that some "free oxygen" is required by this Standard Oil process to support the initial gasification of Coal and "cellulosic materials"; and, to remind you, that, as seen in our report of:
USDOE Algae Recycle CO2 into Liquid Fuels | Research & Development; concerning: "Liquid Fuels from Microalgae; 1987; USDOE; National Renewable Energy Laboratory (NREL), Golden, CO; (The) technology to produce gasoline and diesel fuels from microalgae";
the technology exists to cultivate certain strains of Algae that will, in the course of their normal routine, consume any Carbon Dioxide that might incidentally arise from the process of our subject herein, "United States Patent 2,633,416 - Gasification of Carbonaceous Solids", and, consequently, during normal photosynthesis form at least some of any Oxygen needed for the initial gasification while they go about synthesizing "bio-lipids" that can readily be converted into "gasoline and diesel".
Furthermore, once those "gasoline and diesel" raw materials are extracted from the Algae, what remains is cellular debris consisting primarily of cellulose, which should qualify nicely as the "cellulosic materials", specified herein by Standard Oil to be gasified, right long with Coal, in the production of a blend of Carbon Monoxide and Hydrogen, i.e., "gas mixtures" that are, as again stipulated herein by Standard Oil, "extremely well suited ... for the catalytic synthesis of hydrocarbons".
You know, we've had all of these tools in hand now for many, many decades.
Even the USDOE supplemental Algae cultivation technology is a quarter-century old.
Why, aside from putting any of them to good, productive and needed, use, haven't we even been afforded the privilege of simply being told that these options do exist; and, that they are available for us to use, to use in ways that would free us from overseas military entanglements; ways that would stem the hemorrhage of our national wealth to OPEC; ways that would more fully employ our American citizens; ways that would improve our living environment; and, ways that would clear a path to a sustainable economic future?
The core Carbon conversion-Carbon recycling technology reported in this dispatch is more than one half of a century old.
Why have we, especially those of us resident in United States Coal Country, yet to be publicly told of it?
Further delay is not only inexplicable, it is inexcusable.