United States Patent Application: 0080314242
The concerns about the US EPA's misguided focus on the emission of Mercury in the flue gas of Coal-fired power plants continue to grow, as evidenced by a recent, and overdue, spate of expressions of public alarm about their exercises in regulatory excess, such as:
Is Mercury Just Excuse For EPA? - News, Sports, Jobs - The Intelligencer / Wheeling News-Register; "Is Mercury Just Excuse For EPA; June 24; The Intelligencer / Wheeling News-Register; Environmental Protection Agency officials say we simply must do something about the growing problem of mercury being pumped into the environment. That's interesting in view of a study indicating mercury emitted into the air in the United States decreased by 58 percent from 1990-2005. Mercury is the primary pollutant targeted by the EPA's planned 'Utility MACT' regulations. Critics of the plan point out it will cost the economy billions of dollars a year and will kill tens of thousands of jobs".
As the author of the above points out, and as we have previously documented for you, as with emissions of Carbon Dioxide, emissions of Mercury from all the Coal-fired power plants in the United States of America shrivel to virtual insignificance when compared to the world's total emissions, and even to some specific natural sources of emission, such as, most especially, the inexorable processes of volcanism.
That said, there are potentially-productive, or at least less-negative, ways to deal with the Coal-fired power plant Mercury problem, regardless of what the Mercury problem actually is, i.e., real, or, fabricated and exaggerated.
As we previously documented, in:
West Virginia Coal Association | EPA-Sponsored Fly Ash Concrete Sequesters Flue Gas Mercury | Research & Development; concerning: "United States Patent Application 20030206843 - Methods and Compositions to Sequester Combustion-Gas Mercury in Fly Ash and Concrete; 2003; (Sorbent Technologies Corporation/Albemarle Corporation); The United States Government may own certain rights to present invention pursuant to U.S. Environmental Protection Agency Contract No. 68-D-01-075 and National Science Foundation Award No. DMI-0232735; A method for removing mercury from a combustion gas in an exhaust gas system has the steps of providing a mercury sorbent; injecting the mercury sorbent into a stream of the mercury-containing combustion gas to enable mercury to adsorb onto the sorbent; and collecting and removing the sorbent from the combustion gas stream. Concrete compositions with fly ash containing the mercury sorbents will have reduced interference with air-entraining-admixtures";
the US EPA actually financed development of a technology which would help to enable the collection and sequestration of flue gas Mercury by Coal Fly Ash, which Ash could then be directed for use, as explained by one example:
West Virginia Coal Association | Federal Highway Administration Recommends Fly Ash Concrete | Research & Development; concerning the Federal Highway Administrations report: "Infrastructure Materials Group: Fly Ash; Fly ashes are finely divided residue resulting from the combustion of ground or powdered coal. Use of fly ash in concrete started in the United States in the early 1930's. In addition to economic and ecological benefits, the use of fly ash in concrete improves its workability, reduces segregation, bleeding, heat evolution and permeability, inhibits alkali-aggregate reaction, and enhances sulfate resistance";
in combination with Portland Cement, in the making of a superior Concrete.
And, herein, we learn of a somewhat later, perhaps improved, variation of the technology disclosed by the above-cited "United States Patent Application 20030206843 - Methods and Compositions to Sequester Combustion-Gas Mercury in Fly Ash"; as excerpted from the initial link in this dispatch:
"US Patent Application 20080314242 - Mercury Removal Systems Using Beneficiated Fly Ash
Date: December, 2008
Inventor: Joseph Cochran, Frank Kirkconnell, Vincent Giampa, FL
Assignee: Progress Materials Incorporated, FL
(Recall that we have cited " Progress Materials Incorporated", or "PMI", and Coal Ash scientists Cochran and Giampa, previously, as in our report of:
West Virginia Coal Association | Virginia Converts Coal Ash to Cash | Research & Development; which contained separate discussion of: "United States Patent 7,462,235 - System and Method for Decomposing Ammonia from Fly Ash; 2008; Inventors: Vincent Giampa and Joseph Cochran, FL; Assignee: Progress Materials, Inc., FL; Abstract: A system and method for decomposing ammonia from fly ash contaminated with ammonia is provided".
Note, again, that the company is known by two names, and, though headquartered in North Carolina, also has facilities in Florida; and, you will see both locations and both names cited frequently in the literature. For more explanation, see:
PMI Ash Technologies, LLC: Private Company Information - Businessweek; "PMI Ash Technologies, LLC provides economic ash management solutions. The company ... eliminates fly ash disposal and produces pozzolan for use in concrete. It also produces Aardelite, a lightweight aggregate from non saleable fly ash. PMI Ash Technologies, LLC was formerly known as Progress Materials Inc. The company was founded in 1986 and is based in Cary, North Carolina. It has a facility in Crystal River, Florida". - JtM)
Abstract: A mercury removal system and methods thereof include at least one supply system, at least one cooling system and at least one separation system. The supply system is connected to introduce at least beneficiated fly ash particles into an exhaust stream. The exhaust stream comprises at least one exhaust gas and mercury and at least a portion of the mercury in the exhaust stream adheres to the introduced beneficiated fly ash particles. The cooling system cools the exhaust stream before or after the connection of the supply system to the exhaust stream. The separation system separates from the exhaust stream and outputs at least a portion of the introduced beneficiated fly ash particles with the adhered mercury.
Claims: A mercury removal system comprising: at least one supply system connected to introduce at least beneficiated fly ash particles into an exhaust stream, the exhaust stream comprises at least one exhaust gas and mercury and at least a portion of the mercury in the exhaust stream adheres to the introduced beneficiated fly ash particles; at least one cooling system that cools the exhaust stream; and at least one separation system that separates from the exhaust stream and outputs at least a portion of the introduced beneficiated fly ash particles with the adhered mercury.
The system ... further comprising at least one reactor with a chamber connected to the cooling system to receive the cooled exhaust stream and connected to the supply system to receive the introduced beneficiated fly ash particles in the chamber of the reactor.
The system ... further comprising at least one coal fired burner which supplies the exhaust stream ... .
The system ... wherein the supply system supplies activated carbon in addition to the introduced beneficiated fly ash particles, wherein at least a portion of the mercury in the exhaust stream adheres to the activated carbon (and) wherein the exhaust stream further comprises unbeneficiated exhaust fly ash particles and at least a portion of the mercury in the exhaust stream adheres to the unbeneficiated exhaust fly ash particles.
The system ... wherein the cooling system cools the exhaust stream to a temperature below where the mercury remains in a gaseous state (and) wherein at least 70% of the mercury in the exhaust stream is separated from the exhaust stream.
A method for controlling mercury emissions, the method comprising: introducing at least beneficiated fly ash particles into an exhaust stream, the exhaust stream comprises at least one exhaust gas and mercury and at least a portion of the mercury in the exhaust stream adheres to the introduced beneficiated fly ash particles; cooling the exhaust stream; and separating from the exhaust stream and outputting at least a portion of the introduced beneficiated fly ash particles with the adhered mercury.
The method ... wherein the introducing at least beneficiated fly ash particles further comprises introducing the at least beneficiated fly ash particles into the exhaust stream that further comprises unbeneficiated exhaust fly ash particles, wherein at least a portion of the mercury in the exhaust stream adheres to the unbeneficiated exhaust fly ash particles.
Background and Field: This invention generally relates to systems and methods for mercury removal from an exhaust stream and, more particularly, mercury removal systems using beneficiated fly ash particles and methods thereof. Mercury as a trace element in coal becomes a contaminant in flue gas from coal-fired power plants and other coal fired furnaces. As a result, processes have been developed to capture mercury (Hg) contained in flue gas.
(This section goes on at some considerable length describing the shortcomings of, and difficulties with, similar systems previously proposed. Those discussions are beyond our scope herein; but, it is interesting to observe how much effort has gone into the issue of using Fly Ash to extract flue gas Mercury.)
Summary: A mercury removal system in accordance with embodiments of the present invention includes at least one supply system, at least one cooling system and at least one separation system. The supply system is connected to introduce at least beneficiated fly ash particles into an exhaust stream. The exhaust stream comprises at least one exhaust gas and mercury and at least a portion of the mercury in the exhaust stream adheres to the introduced beneficiated fly ash particles. The cooling system cools the exhaust stream before or after the introduction of the beneficiated fly ash particles by the supply system to the exhaust stream. The separation system separates from the exhaust stream and outputs at least a portion of the introduced beneficiated fly ash particles with the adhered mercury.
The present invention provides a number of advantages including providing an effective and less expensive system and method for introducing a material or materials to capture mercury in an exhaust stream. With the present invention, mercury in the exhaust steam or flue gas directly from a coal fired burner, such as a power plant boiler, or other furnace, can be captured with introduced beneficiated fly ash particles. These introduced, beneficiated fly ash particles are less expensive than activated carbon and provide the unpredictable result of being highly effective in capturing mercury when introduced despite their low carbon content, e.g. below about three percent. Since they become combined with any fly ash particles entering with the exhaust stream, the combined carbon content of the fly ash particles will determine whether the combined fly ash stream requires further processing in the fly ash thermal beneficiation process to reduce carbon content before being put to other beneficial uses with the captured mercury, such as a direct replacement for Portland cement."
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One caveat, of course, would be that "further processing in the fly ash thermal beneficiation process", i.e., the "Carbon Burn-Out", to remove the fresh Carbon attached to the extra "unbeneficiated exhaust fly ash particles" acquired from the exhaust stream along with the Mercury, could re-volatilize the captured Mercury.
However, the newly-added Carbon would, as a percentage of the total mass, since the total is comprised in part of beneficiated Fly Ash, only be a fraction of that originally present in unbeneficiated Fly Ash; and, other, non-thermal methods, as we will document in a future report or two, have been developed to effectively "passivate" that smaller amount of Carbon residue, so that the Ash would then still be suitable either as an additive to or "direct replacement for Portland cement" in the making of Concrete.
And, that would be especially true, if, in the first place, the beneficiated Fly Ash had been further treated with the additive sorbent disclosed in the above-cited "United States Patent Application 20030206843 - Methods and Compositions to Sequester Combustion-Gas Mercury in Fly Ash and Concrete" prior to use of the Fly Ash in the flue gas Mercury extraction process.
Further, the Mercury content of the Ash, after the Coal power plant flue gas Mercury removal, would not necessarily preclude use of the contaminated Ash as a raw material in the actual making of the Portland Cement itself, in addition to it's use as an additive to Portland Cement, as discussed for one example in:
West Virginia Coal Association | Pittsburgh Converts Coal Ash and Flue Gas into Cement | Research & Development; concerning: "United States Patent 5,766,339 - Producing Cement from a Flue Gas Desulfurization Waste; 1998; Dravo Lime Company, Pittsburgh; Cement is produced by forming a moist mixture of a flue gas desulfurization process waste product containing 80-95 percent by weight calcium sulfite hemihydrate and 5-20 percent by weight calcium sulfate hemihydrate, aluminum, iron, silica and carbon, agglomerating the moist mixture while drying the same to form a feedstock, and calcining the dry agglomerated feedstock in a rotary kiln. (And,) wherein said source of aluminum and iron comprises fly ash".
As seen in:
08/09/2010: EPA Sets First National Limits to Reduce Mercury and Other Toxic Emissions from Cement Plants; "Date: 08/09/2010; Washington; The U.S. Environmental Protection Agency (EPA) is issuing final rules that will (cut) emissions of mercury ... from Portland cement manufacturing, the third-largest source of mercury air emissions in the United States";
Portland Cement manufacturing facilities are also already blamed for emitting Mercury, and, are being compelled to install their own devices and procedures to capture it. Thus, there might exist some potential for partnership between Coal-fired electric utilities and Cement manufacturing plants to efficiently pool their resources and, in a more economical way, share the costs of Mercury removal at one centralized and concentrated point source of emission: the Portland Cement kiln.
It seems to us that a genuinely beneficial, on several levels, partnership could be developed that way.
And, in closing, we'll note that such positive potentials for productivity and partnership don't exist for or extend to one profligate source of Mercury emissions.
As seen in:
EPA/600/R-01/066 | Risk Management Research | Risk Management Research | US EPA; Mercury in Petroleum and Natural Gas: Estimation of Emissions From Production, Processing, and Combustion; "(EPA/600/R-01/066) September 2001; The mercury associated with petroleum and natural gas production and processing ... may exceed 10,000 kilograms yearly";
"America's Clean Energy Alternative" has a wee bit of Mercury problem, too. Although, given their clout and public press high status, we don't know how assiduously the US EPA is being allowed to hold them accountable for their many sins.
In any case, the Mercury problem does have a solution. One that, even though it might not itself, on it's own, result in a profit, could result in reduced costs of compliance, and in some genuine commercial synergies, for both the Coal-fired power generation and the Cement manufacturing industries.
