We have many times documented the USDOE-funded International Coal Refining (ICR) operation, a Coal liquefaction joint venture of the Air Products and Chemicals Company and Wheelabrator-Frye, Inc.; as most recently in: USDOE Funds Pennsylvania Coal Liquefaction | Research & Development.
Without linking to other of our earlier reports, we remind you that ICR itself was type of "Solvent Refined Coal", or "SRC", Coal liquefaction pilot-scale factory near Allentown, PA.
We have, in some of those earlier reports, noted that other entities, as well, participated in the development and operation of the ICR plant, and, herein, we learn, indirectly, that the University of Kentucky's Center for Applied Energy Research was one of those participants.
Although the rights to the US Patent we enclose herein - - for an improvement on Coal liquefaction technology, which seems, to our uneducated and imperfect eyes, very closely-related to standard petroleum refinery distillation column operations for the separation of hydrocarbon products - - are assigned to the International Coal Refining Company itself, web-based resources identify the named inventors' affiliations, at that time, to be as we parenthetically indicate in our excerpts from the link to:
"United States Patent 4,511,460 - Minimizing Corrosion in Coal Liquid Distillation
Date: April, 1985
Inventors: Kenneth Baumert, PA, (Air Products and Chemicals); Alberto Segues and Burtron Davis, KY, (University of Kentucky)
Assignee: International Coal Refining Company, Allentown, PA
Government Interests: The Government of the United States of America has rights in this invention pursuant to Contract No. DE-AC05780R03054 (as modified) awarded by the U.S. Department of Energy.
Abstract: In an atmospheric distillation tower of a coal liquefaction process, tower materials corrosion is reduced or eliminated by introduction of boiling point differentiated streams to boiling point differentiated tower regions.
Claims: A coal liquefaction fractionation process including a distillation tower to reduce the presence of amine hydrochlorides therein, wherein said distillation tower separates coal liquids ... .
A coal liquefaction fractionation process including a distillation tower to reduce the presence of amine hydrochlorides therein, wherein said distillation tower separates coal liquids containing nitrogen compounds.
Description and Background: A necessary step in the production of solvent refined coal (SRC) and other coal liquefaction products is a solvent fractionation or distillation step. Such fractionation is usually accomplished in a distillation tower at atmospheric or below atmospheric pressures. It has been found that the synergistic reaction which contributes to corrosion in the tower involves chloride containing species in combination with low boiling weakly basic nitrogen containing streams.
In an effort to reduce or eliminate corrosion in coal liquid fractionation towers, several methods have been tested and/or used. These techniques are usually directed to neutralizing the coal liquid streams. Towers used in coal tar distillation have been maintained at low levels of corrosion by the injection of sodium carbonate into the tower as a solution. However, the solvent flashes and resulting sodium carbonate solid drops out near the injection point. As a result, the tower has a tendency to plug near the injection point and must be taken out of service for frequent cleaning.
Injection of sodium hydroxide to the tower has also been used. Because sodium hydroxide is a stronger base, the quantities required to prevent corrosion are lower. However, polymerization of hydrocarbons in the tower is promoted by the strength of the base and can cause plugging problems.
Sodium carbonate addition of feed coal has proven to be effective at reducing corrosion of the fractionation apparatus. However, (there are) competing reactions with aluminum, silicon, and sulfur. In addition, most of the sodium ends up in the ash and is thus detrimental to the gasifier. Finally, this amount of sodium carbonate addition to the process is extremely costly.
Other techniques such as water washing the incoming stream and side stream draw off have been considered and tested in the laboratory. These techniques are either impractical due to energy considerations or present problems in dealing with the waste they create.
It is a primary object of the present invention to substantially reduce or eliminate corrosion in the coal liquid fractionation tower of a coal liquefaction facility.
It is yet another object of the present invention to reduce or eliminate coal liquid fractionation tower corrosion while maintaining both energy efficiency and economy.
It is a further object of this invention to eliminate coal liquid fractionation tower corrosion while not contributing to tower plugging.
The present invention reduces formation of the acidic amine hydrochlorides primarily responsible for corrosion in coal liquefaction system fractionation systems ... ."
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Without citing any of our prior reports, we remind you that we have previously documented efforts, by other entities, to resolve issues associated with corrosion, as above, in equipment that further processes the products of an initial Coal gasification process.
And, we'll note, that: The corrosion problems stem from "chloride containing species" acting "in combination with low boiling weakly basic nitrogen containing streams".
As in the above, some of that "nitrogen" does come from the Coal itself. However, the bulk of it likely arises from the fact that the initial Coal gasification is accomplished by utilizing unpurified, and thus much cheaper, air, to support the partial oxidation process, as opposed to utilizing more expensive purified Oxygen, or, better, a blend of purified Oxygen and Steam, which, presuming you to have followed our posts thus far, also enables the co-generation of additional Hydrogen for the improved hydrogenation of the Coal-derived gases and liquids.
In brief, our consultants suggest that the process disclosed by this US Patent is actually a "band aid" approach to solving a problem that could be at least partly prevented in the first place, by a larger, up-front investment in Oxygen purification and/or Steam generation equipment, so that unpurified, Nitrogen-
Another option, related to earlier reports we've submitted concerning China's indirect Coal conversion industry, is to provide more elemental Hydrogen to the gasification process, and thereby convert more of the Nitrogen entrained in the gasification medium into relatively non-corrosive Ammonia, NH4, which can then, as those earlier reports concerning China's technical plans reveal, be recovered and utilized in the manufacture of fertilizer.
The extra Hydrogen would be an expense, but that expense might well be more than offset by a reduction in corrosion problems and by the sales of by-product Ammonia.
And, there is likely to be, as our consultants again suggest, an "optimal" cost hybrid solution, wherein plain air that has simply been Oxygen enriched, but still contains some Nitrogen, can be utilized, perhaps in combination with some Steam, or with another source of a certain amount of elemental Hydrogen, thus producing some smaller amount of Ammonia, but also reducing the amount of "amines" that might be produced, and which would thus be available to interact with any "chlorides" which might be present, to thereby form the chemical agents of corrosion.