Any search for emerging technology should include a search of the USPTO
database (http://patft.uspto.gov/netahtml/PTO/index.html). The database is divided into two parts …
USPTO patents that have been granted
USPTO patents that have been applied for
Because the USPTO Patent Applications represent patents that have not yet been granted, they also represent newer inventions.
However, just because a patent has been granted does not mean that the USPTO Patents is not worth searching. You should search them both.
Some interesting results are produced when you search the USPTO Patent Search for DESULFURIZATION in TITLE
As of the date of this post, the first 6 are Saudi Aramco patents …
USPTO patents that have been granted
USPTO patents that have been applied for
Because the USPTO Patent Applications represent patents that have not yet been granted, they also represent newer inventions.
However, just because a patent has been granted does not mean that the USPTO Patents is not worth searching. You should search them both.
Some interesting results are produced when you search the USPTO Patent Search for DESULFURIZATION in TITLE
As of the date of this post, the first 6 are Saudi Aramco patents …
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The results are useful in several ways.
First, they reveal that Saudi Aramco is extremely interested in developing innovative desulfurization technologies. Tbis may suggest a business opportunity. Saudi Aramco has a venture capital unit (https://saev.com/) called Saudi Aramco Energy Ventures. If your concept fits Aramco’s strategic needs, you may be able to use Aramco capital to further your research.
Second, many of the same inventor names appear over and over in the Saudi Aramco patents. You may be able to find them on LinkedIn (https://www.linkedin.com/) and invite them to join your network.
Here are descriptions of some of the other patents resulting from the above search …
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United States Patent 9,555,341
Ukai , et al. January 31, 2017
Spray-drying device for dehydrated filtrate from desulfurization wastewater, air pollution control system and flue gas treatment method
Abstract
A spray-drying device includes a spray nozzle that sprays the dehydrated filtrate from the desulfurization wastewater, in a spray-drying device body, an inlet that is provided in the spray-drying device body and introduces flue gas for drying spray liquid, a dry area that is provided in the spray-drying device body and dries the dehydrated filtrate by the flue gas, an outlet that discharged the flue gas contributing to the drying, a plurality of thermometers that are provided in the dry area and measure temperatures of the inside, a determination unit that determines whether or not a spray-drying state of the dehydrated filtrate is satisfactory on the basis of the measurement results of the thermometers, and a control unit that adjusts the flue gas or the dehydrated filtrate when it is determined that the spray-drying is not satisfactory as a result of the determination of the determination unit.
Inventors:
Ukai; Nobuyuki (Tokyo, JP), Nagayasu; Tatsuto (Tokyo, JP), Kamiyama; Naoyuki (Tokyo, JP), Kagawa; Seiji (Tokyo, JP), Fukuda; Toshihiro (Tokyo, JP)
Applicant:
Ukai; Nobuyuki, Nagayasu; Tatsuto, Kamiyama; Naoyuki, Kagawa; Seiji, Fukuda; Toshihiro
Assignee:
Mitsubishi Power Systems, Ltd. (Tokyo, Jp)
The invention claimed is:
1. A spray-drying device connected to a first line from which a flue gas is supplied via a first valve, a second line from which a desulfurization water is supplied from a desulfurization device via a second valve and a third line from which the flue gas is discharged comprising: a spray-drying device body; a spray nozzle that is connected to the second line and provided at a top portion of the spray-drying device body to spray the desulfurization water into the spray-drying device body; an inlet that is connected to the first line and provided at an upper portion of the spray-drying device body to introduce the flue gas into the spray-drying device body; an outlet that is connected to the third line and provided at a lower portion of the spray-drying device body to discharge the flue gas contributing to the drying; a plurality of thermometers that are serially provided in the spray-drying device body below the spray nozzle to obtain a temperature distribution inside of the spray-drying device body; a determination unit that determines whether or not a spray-drying state of the dehydrated filtrate is satisfactory on the basis of the temperature distribution as a function of positions of the plurality of thermometers and outputs a result of the determination; and a control unit that controls the first valve or the second valve in response to the result of the determination.
2. The spray-drying device according to claim 1, wherein the determination unit is configured to determine, (i) that the spray-drying is satisfactory when the temperature distribution has a constant portion, or (ii) that the spray-drying is not satisfactory when the temperature distribution continuously decreases toward the outlet.
3. An air pollution control system comprising: a boiler that burns fuel; an air heater that recovers heat of flue gas from the boiler; a precipitator that removes soot dust of the flue gas after the heat recovery; a desulfurization device that removes sulfur oxides included in the flue gas after the dust removal by an absorbent; a dehydrator that removes gypsum from desulfurization water discharged from the desulfurization device; the spray-drying device according to claim 1 provided with a spray unit that sprays the dehydrated filtrate from the dehydrator; a flue gas introduction line as the first line to supply a part of the flue gas into the spray-drying device; a desulfurization wastewater line as the second line that connect the dehydrator to the spray-drying device to supply the desulfurization water into the spray-drying device; and an flue gas supply line as the third line that supplies the flue gas contributing to the drying to a gas supply line.
4. The air pollution control system according to claim 3, further comprising a solid-liquid separation device that removes suspended substances of the dehydrated filtrate sprayed from the dehydrator.
Description
FIELD
The present invention relates to a spray-drying device for dehydrated filtrate from desulfurization wastewater generated at the time of flue gas treatment of treating flue gas discharged from a boiler, air pollution control system and method.
BACKGROUND
In the related art, an air pollution control system for treating flue gas discharged from a boiler provided in thermal power generation facilities is known. The air pollution control system is provided with a denitration device that removes nitrogen oxides from the flue gas discharged from the boiler, an air heater that recovers heat of the flue gas passing through the denitration device, and a precipitator that removes soot dust of the flue gas after the heat recovery, and a desulfurization device that removes sulfur oxides of the flue gas after the dust removal. As the desulfurization device, a wet-type desulfurization device that brings a limestone absorbent into gas-liquid contact with the flue gas to remove the sulfur oxides of the flue gas is generally used.
Wastewater (hereinafter, referred to as "desulfurization wastewater") discharged from the wet-type desulfurization device includes a large amount of various harmful substances such as ions such as chlorine ions and ammonium ions and mercury. For this reason, it is necessary to remove such harmful substances from the desulfurization wastewater before discharging the desulfurization wastewater out of the system, but there is a problem that treatment of removing various harmful substances included in the desulfurization wastewater is complex and a treatment cost is high. Therein, in order to reduce the treatment cost of the desulfurization wastewater, a method of reusing the desulfurization wastewater in the system without discharging it out of the system is proposed. For example, in Patent Literatures 1 and 2, an flue gas treatment device is disclosed, in which facilities branched from an flue gas duct of a main line, to which the denitration device, the air heater, the precipitator, and the desulfurization device are connected, and spraying the desulfurization wastewater to form gas are separately provided, a part of the flue gas is introduced from the flue gas duct of the main line into the facilities, the desulfurization wastewater is sprayed into the flue gas in the facilities to be evaporated to precipitate the harmful substances, and then the gas is returned to the flue gas duct of the main line (Patent Literatures 1 and 2).
SUMMARY
Technical Problem
However, in the flue gas treatment device of Patent Literatures 1 and 2, facilities in which a part of the flue gas is branched from the flue gas duct and the desulfurization wastewater (or drainage water) is sprayed from the desulfurization device to form gas are provided, to evaporate the desulfurization wastewater. However, the desulfurization wastewater from the desulfurization device contains solid contents, and thus there is a problem that it is difficult to satisfactorily perform the spray-drying.
In addition, recently, for environment-friendliness with respect to water resources in inland regions, non-drainage in the flue gas treatment facilities is desired, and thus appearance of flue gas treatment facilities to achieve stably operable non-drainage is desired.
As facilities performing the non-drainage, a spray drier that dries the desulfurization wastewater may be used, but there are the following problems in the case of performing the spray-drying of the desulfurization wastewater.
1) Problem Caused by Disarray of Heat Quantity Balance
To evaporate the spray liquid, drying is promoted by heat exchange between the spray liquid and warm air, but an evaporation defect occurs when the spray liquid is excessive with respect to the warm air.
2) Problem Caused by Coarsening of Liquid Droplets Diameter of Spray Liquid by Ash Attachment
When ash is attached to a spray nozzle leading end portion, the spray liquid droplet diameters generated from the nozzle are changed to be generally coarsened. In the coarsened liquid droplets, a specific surface area subjected to heat exchange with the warm air is small, the heat exchange is slow, and thus an evaporation delay occurs.
The invention has been made to solve the problems, and an object of the invention is to provide a spray-drying device of dehydrated filtrate from desulfurization wastewater, an air pollution control system, and a flue gas treatment method, to achieve stably operable non-drainage.
Solution to Problem
According to a first aspect of the present invention in order to solve the problems, there is provided a spray-drying device for dehydrated filtrate from desulfurization wastewater including: a spray nozzle that sprays the dehydrated filtrate from the desulfurization wastewater, in a spray-drying device body; an inlet that is provided in the spray-drying device body and introduces flue gas for drying spray liquid; a dry area that is provided in the spray-drying device body and dries the dehydrated filtrate by the flue gas; an outlet that discharges the flue gas contributing to the drying; a plurality of thermometers that are provided in the dry area and measure temperatures of the inside; a determination unit that determines whether or not a spray-drying state of the dehydrated filtrate is satisfactory on the basis of the measurement results of the thermometers; and a control unit that adjusts the flue gas or the dehydrated filtrate when it is determined that the spray-drying is not satisfactory as a result of the determination of the determination unit.
According to a second aspect of the present invention, there is provided the spray-drying device for the dehydrated filtrate from the desulfurization wastewater according to the first aspect, wherein the adjustment of the dehydrated filtrate is performed by increasing or decreasing the supply amount of dehydrated filtrate or increasing or decreasing the supply amount of atomized air.
According to a third aspect of the present invention, there is provided the spray-drying device for the dehydrated filtrate from the desulfurization wastewater according to the first aspect, wherein the adjustment of the flue gas is performed by controlling the introduction amount of flue gas.
According to a fourth aspect of the present invention, there is provided the spray-drying device for the dehydrated filtrate from the desulfurization wastewater according to any one of the first to third aspect, wherein it is determined whether or not the spray-drying is satisfactory on the basis of a temperature decrease degree.
According to a fifth aspect of the present invention, there is provided an air pollution control system including: a boiler that burns fuel; an air heater that recovers heat of flue gas from the boiler; a precipitator that removes soot dust of the flue gas after the heat recovery; a desulfurization device that removes sulfur oxides included in the flue gas after the dust removal by an absorbent; a dehydrator that removes gypsum from desulfurization wastewater discharged from the desulfurization device; the spray-drying device according to any one of the first to fourth aspects provided with a spray unit that sprays the dehydrated filtrate from the dehydrator; and
a flue gas introduction line that introduces a part of the flue gas into the spray-drying device.
According to a sixth aspect of the present invention, there is provided the air pollution control system according to the fifth aspect, further including a solid-liquid separation device that removes suspended substances of the dehydrated filtrate sprayed from the dehydrator.
According to a seventh aspect of the present invention, there is provided a flue gas treatment method including: recovering heat of flue gas from a boiler that burns fuel by an air heater; and removing, by a desulfurization device, sulfur oxides included in the flue gas after the heat recovery by an absorbent, wherein when spray-drying of dehydrated filtrate in which gypsum is removed from desulfurization wastewater discharged from the desulfurization device is performed by a part of the flue gas, the spray-drying state of the dehydrated filtrate is performed while monitoring a temperature state in the dry area.
According to an eighth aspect of the present invention, there is provided the flue gas treatment method according to the seventh aspect, wherein spray-drying of separation liquid from which suspended substances of the dehydrated filtrate is removed is performed.
Advantageous Effects of Invention
According to the invention, when the dehydrated filtrate from which gypsum is excluded from the desulfurization wastewater divided from the desulfurization device using the flue gas from the boiler is sprayed by the spray drier, the spray-drying state is checked. When there is a spray defect, it is removed to perform stable spraying. Accordingly, it is possible to realize the non-drainage of the desulfurization wastewater from the desulfurization device.
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=7&f=G&l=50&co1=AND&d=PTXT&s1=desulfurization.TI.&OS=TTL/desulfurization&RS=TTL/desulfurization
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United States Patent 9,515,338
Budge December 6, 2016
Fuel cell system and desulfurization system
Abstract
One embodiment of the present invention is a unique fuel cell system. Another embodiment is a unique desulfurization system. Yet another embodiment is a method of operating a fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and desulfurization systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.
Inventors:
Budge; John R. (Beachwood, OH)
Assignee:
LG Fuel Cell Systems Inc. (North Canton, OH)
Description
FIELD OF THE INVENTION
The present invention relates to desulfurization systems and fuel cell systems with desulfurization systems.
BACKGROUND
Fuel cell systems and desulfurization systems that effectively remove or reduce sulfur content in fuel remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.
SUMMARY
One embodiment of the present invention is a unique fuel cell system. Another embodiment is a unique desulfurization system. Yet another embodiment is a method of operating a fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and desulfurization systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=9&f=G&l=50&co1=AND&d=PTXT&s1=desulfurization.TI.&OS=TTL/desulfurization&RS=TTL/desulfurization
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The same search, i.e., DESULFURIZATION in TITLE, in the USPTO Patent Applications section results in the following, among other items …
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United States Patent Application 20170058205
Ho; Tekliong ; et al. March 2, 2017
Non-Oxidized Desulfurization Process and Method of Using the Same
Abstract
A non-oxidized diesel desulfurization process that uses temperature swing adsorption along with an adsorbent to adsorb sulfur compounds and other impurities petroleum-based from fuel compositions, including light distillates, middle distillates, diesel, gasoline and transmix. The process uses temperature cycling of an adsorbent bed to adsorb and desorb organosulfur compounds and other impurities. Once the adsorbent reaches a selected concentration of sulfur compounds, the temperature of the adsorbent bed is raised to desorb sulfur compounds, using a regenerant.
Inventors: Ho; Tekliong; (Los Alamitos, CA) ; Albakri; Luay; (Los Alamitos, CA) ; Greene; William; (Long Beach, CA)
Applicant:
SpinTek Filtration, Inc.
Los Alamitos CA
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a desulfurization process for removing sulfur compounds and other impurities from petroleum-based fuel compositions.
BACKGROUND OF THE INVENTION
[0002] Sulfur-containing compounds are a component in petroleum-based fuels that can potentially form harmful compounds in the environment when the fuel is ignited or combusted. The sulfur-containing compounds can be converted into sulfur dioxide, which can then be converted into sulfur-based acids in the atmosphere. The acids are then mixed with rain to form so-called "acid rain." In addition, sulfur-containing compounds can also reduce the effectiveness of catalytic converters, leading to an increase in nitrous oxide (NO.sub.x) emissions.
[0003] In order to reduce air pollution and the negative environmental impact associated with petroleum-based fuels, various technologies have been developed to reduce sulfur and other harmful emissions while maintaining fuel efficiency. Fuel quality standards have been imposed for the control of such emissions through the reduction in sulfur content in petroleum-based fuels.
[0004] Sulfur contents in crude oils may include the following: [0005] 1) Free elemental sulfur; [0006] 2) Mercaptans and thiols (R--SH); [0007] 3) Hydrogen sulfide; [0008] 4) Sulfides; [0009] 5) Disulfides (R--S--S--R'); [0010] 6) Poly sulfides (R--S.sub.n--R'); and [0011] 7) Thiophenes and their derivatives (including benzothiophenes and dibenzothiophenes.
[0012] Petroleum products are usually grouped into several categories: light distillates (LPG, gasoline, naphtha), middle distillates (kerosene, diesel), and heavy distillates and residuum (heavy fuel oil, lubricating oils, wax, asphalt). This classification is based on the way crude oil is distilled and separated into fractions.
[0013] Diesel is a multi-purpose middle distillate petroleum fuel that is widely used in trucks, trains, boats, buses, planes, heavy machinery and off-road vehicles. It also remains one of the largest sources of fine particulate air pollution. Sulfur, a natural part of the crude oil from which diesel fuel is derived, is one of the key causes of particulates or soot in diesel. Soot is the main culprit of diesel engines' noxious black exhaust fumes, and is among the prime contributors to air pollution. Besides soot, diesel fueled engines also emit nitrogen oxides that can form ground level ozone.
[0014] Beginning in 2001, the U.S. Environmental Protection Agency passed rules requiring the use of ultra-low sulfur diesel (ULSD) in diesel engines including trucks, buses, construction equipment, as well as stationary sources. ULSD must be refined so that its sulfur content is 15 parts per million (ppm) or less. The move toward ULSD is aimed at lowering diesel engines' harmful exhaust emissions and improving air quality. Low-sulfur fuel is typically defined as having less than 500 ppm sulfur, and uncontrolled sulfur diesel may have levels that are much higher.
[0015] It is generally known that the sulfur content in diesel and other fuels can be reduced by hydrodesulfurization (HDS), which is a standard desulfurization process in the oil/petrochemical industry. Hydrodesulfurization involves contacting of hydrogen with the hydrocarbon stream in a packed bed reactor in the presence of a catalyst at elevated temperatures and pressures to convert sulfur products present therein into hydrogen sulfide. The catalysts used in the HDS process typically comprise ruthenium and/or transitional metals. While ruthenium is the most active catalyst, it is also expensive and relatively toxic, which has led to the extensive use of transitional metal catalyst binary metals on various catalyst supports. These transitional metal catalysts include, but are not limited to, molybdenum-cobalt, nickel-tungsten and nickel-molybdenum, among others. Nickel-tungsten and nickel molybdenum are commonly used for processing middle distillate, which typically contains organic nitrogen compounds and the ability to remove organic nitrogen by uses of these catalysts is essential for increasing the effectiveness of the desulfurization process. The hydrogen sulfide gas produced may then be subsequently converted into byproduct elemental sulfur or sulfuric acid.
[0016] Hydrodesulfurization processes are described, for example, in U.S. Pat. No. 6,126,814 to Lapinski et al., U.S. Pat. No. 6,013,598 to Lapinski et al. and in U.S. Pat. No. 5,985,136 to Brignac et al., the subject matter of each of which is herein incorporated by reference in its entirety. In one such process, diesel with a high sulfur content goes through two consecutive stages of hydrogen treatment: the first stage removes smaller sulfur compound molecules and thereafter the second stage removes larger molecules. The first stage operates at a temperature of about 300.degree. C. and a pressure of about 650 psi. This high temperature and pressure is necessary to reduce the wetting barrier between solid, diesel and hydrogen. The second stage operates at a temperature of about 400.degree. C. and a pressure of about 850 psi. This higher temperature in the second stage is required to mitigate the higher resistance to mass transfer of the more sterically hindered sulfur compounds such as benzothiophenes, dibenzothiophenes, etc.
[0017] However, the hydrodesulfurization process not only reduces the amount of sulfur and sulfur-containing compounds in the fuel, but also breaks apart olefins and reduces the amount of other heteroatom-containing compounds, including nitrogen-containing and oxygen-containing compounds in the fuel, and reduces the aromatic amount in the middle distillate. Breaking middle distillate fuel into a lighter gas is not economical since the middle distillate is more valuable than that of the byproduct gases. In addition, reducing aromatics in the middle distillate has adverse effects on the fuel quality, including reducing lubricity, increasing tear-wear in pistons, lowering the efficiency of the engine and increasing engine knocking. The hydrodesulfurization process is also unable to achieve ultra-low sulfur levels in the fuel due to the low reactivity of refractory sulfur species under conventional conditions and also strong inhibition of the reaction by the reaction products H.sub.2S, NH.sub.3, nitrogen and aromatic species.
[0018] To achieve the required reductions in sulfur content in the fuel, the operating conditions of hydrogen desulfurization need to be more severe with respect to both temperature and pressure, which can also lead to an increased process cost. Furthermore, while the concentration of thiophenes and, to a lesser extent, benzothiophenes can be reduced to the required levels by hydrodesulfurization, the reduction in concentration of other sulfur species, such as dialkyl dibenzothiophenes can be more problematic.
[0019] More recently, an oxidative desulfurization (ODS) process has been developed, as described, for example, in U.S. Pat. No. 8,088,711 to Choi and U.S. Pat. No. 8,016,999 to Borgna et al., the subject matter of each of which is herein incorporated by reference in its entirety. In the ODS process, the fuel is contacted with an oxidant such as hydrogen peroxide, ozone, nitrogen dioxide, or tert-butyl-hydroperoxide, in order to selectively oxidize the sulfur compounds present in the fuel to polar organic compounds. These polar compounds can be easily separated from the hydrophobic hydrocarbon based fuel via solvent (liquid) extraction using solvents such as alcohols, amines, ketones or aldehydes, for example. This process operates at ambient temperature and pressure, which allows for a significant cost reduction.
[0020] However, the catalysts used in this process typically comprise phosphate derivatives, tungstate derivatives, etc., which are generally non-regenerable. The catalysts are usually added into organic liquids prior to being mixed with the middle distillate or other fuel. Organic peroxide is one of the most commonly used oxidizing agents in the ODS process and the use and storage of organic peroxide can be hazardous, causing safety concerns. After oxidation, the organic sulfur compounds are extracted from the hydrocarbon using an organic liquid, such as acetonitrile. During the extraction of sulfone, large amounts of hydrocarbons are also removed from the middle distillate into an acetonitrile phase. In addition, the sulfoxide created by ODS cannot be treated by HDS.
[0021] Thus, it can be seen that there remains a need in the art for an improved process for removing sulfur compounds from petroleum-based fuel that overcomes the deficiencies of the prior art.
SUMMARY OF THE INVENTION
[0022] It is an object of the present invention to provide an efficient method of reducing the sulfur content of petroleum-based fuel feed stocks.
[0023] It is another object of the present invention to provide an efficient method of producing diesel or other middle-distillate fuel that is substantially free of sulfur and other impurities.
[0024] It is another object of the present invention to provide a method of removing sulfur and other impurities from petroleum-based fuel feed stocks that does not require high temperatures.
[0025] It is still another object of the present invention to provide a method of removing sulfur and other impurities from petroleum-based fuel feed stocks that does not require high pressures.
[0026] It is still another object of the present invention to provide a method of removing sulfur and other impurities from petroleum-based fuel feed stocks that is non-selective.
[0027] It is still another object of the present invention to provide a method of removing sulfur and other impurities from petroleum-based fuel feed stocks using an adsorbent that is reusable.
[0028] It is still another object of the present invention to provide a method of removing sulfur and other impurities from petroleum-based fuel feed stocks using an adsorbent that is regenerable.
[0029] To that end, in one embodiment, the present invention relates generally to a method for removing impurities from a petroleum-based fuel composition using temperature swing adsorption, the method comprising the steps of:
[0030] a) feeding a petroleum-based fuel composition containing impurities to a series of packed bed columns, wherein the series of packed bed columns comprise an adsorbent capable of adsorbing the impurities from the petroleum-based feed composition at a first temperature;
[0031] b) adsorbing the impurities in the petroleum-based feed composition onto the adsorbent in the series of packed columns at the first temperature; and
[0032] c) removing treated petroleum-based fuel from the series of packed bed columns.
[0033] In another embodiment, the present invention relates generally to a temperature swing adsorption system for removing impurities from a petroleum-based fuel composition, the temperature swing adsorption system comprising:
[0034] a. a plurality of packed bed adsorbers, wherein the plurality of packed bed adsorbers are arranged in an N+1 configuration, wherein N packed bed adsorbers operate in series and one adsorber is offline, and wherein the plurality of packed bed adsorbers comprise an adsorbent capable of adsorbing impurities from the petroleum-based fuel composition at a first temperature;
[0035] b. an inlet for feeding the petroleum-based fuel composition to be treated into the plurality of packed bed adsorbers;
[0036] c. an outlet for removing the treated petroleum-based fuel composition from the plurality of packed bed adsorbers; and
[0037] d. means for controlling temperature and pressure in the system.
[0038] In another embodiment, the present invention relates generally to an adsorbent for removing impurities from a petroleum-based fuel composition in a temperature swing adsorption process, wherein the adsorbent comprises a porous support impregnated with a sorbent mixture.
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=2&f=G&l=50&co1=AND&d=PG01&s1=desulfurization.TTL.&OS=TTL/desulfurization&RS=TTL/desulfurization
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United States Patent Application 20170056822
Woodward; Brian Clair March 2, 2017
Methods And Systems For Inhibiting Crystalline Buildup In A Flue Gas Desulfurization Unit
Abstract
Methods and systems for inhibiting buildup of crystalline materials in a flue gas desulfurization (FGD) unit. Crystalline materials can accumulate in FGD units as a byproduct of chemical desulfurization processes and can adversely impact FGD unit function. The systems described in the present application include an FGD unit with one or more selected bacterial strains disposed therein. It is believed that the bacteria may form a biofilm on the surfaces in the FGD and/or form a biosurfactant to inhibit or prevent buildup of crystalline materials in the FGD unit. Methods include inoculating an FGD unit with one or more selected bacteria that inhibit or prevent buildup of crystalline materials in the FGD unit. Methods may include periodic reinoculation of the FGD unit.
Inventors: WOODWARD; BRIAN CLAIR; (Evanston, WY)
Applicant:
Big Monkey Services, LLC
Evanston WY
Description
BACKGROUND
[0001] Coal-fired electricity-generating plants may use sulfur dioxide (SO.sub.2) scrubbers to reduce the amount of SO.sub.2 that is discharged into the atmosphere. This is good environmental practice and is generally mandated by environmental regulations in most countries, including the United States, Canada, and all of Western Europe. Additionally, scrubbers can trap pollutants like mercury and other heavy metals that would otherwise be discharged with the flue gas. SO.sub.2 emissions are known to cause detrimental impacts on human health and the environment. The major health concerns associated with exposure to high ambient concentrations of SO.sub.2 include breathing difficulty, respiratory illness, and aggravation of existing cardiovascular disease. In addition to the health impacts, SO.sub.2 leads to acid deposition (e.g., acid rain) in the environment. This deposition causes acidification of lakes and streams and damage to tree foliage and agricultural crops. Furthermore, acid deposition accelerates the deterioration of buildings and monuments. While airborne, SO.sub.2 and its particulate matter (PM) derivatives contribute to visibility degradation.
[0002] Combustion of sulfur-containing fuels, such as coal and oil, results in SO.sub.2 formation. Electricity-generating plants account for the majority of SO.sub.2 emissions in the United States. The Acid Rain SO.sub.2 Reduction Program, established under Title IV of the Clean Air Act Amendments of 1990, was designed to reduce SO.sub.2 emissions from the power-generating industry. Phase I of this program began on Jan. 1, 1995, and ended on Dec. 31, 1999. In 1997, 423 electricity-generating units, affected under Phase I, emitted 5.4 million tons (4903.2.times.10.sup.6 kg) of SO.sub.2 compared with the allowable 7.1 million tons (6446.8.times.10.sup.6 kg). Phase II of the Acid Rain SO.sub.2 Reduction Program began on Jan. 1, 2000. To meet the requirements of this phase, some power plants may use flue gas desulfurization (FGD) technologies. Additional environmental benefits that may result from the use of these technologies are synergistic reductions in Hg and other pollutant emissions, as well as reductions in fine PM concentrations in the atmosphere.
[0003] However, FGD technologies present a number of operational challenges. For instance, FGD scrubber units are subject to large amounts of buildup that may, over time, restrict the flow of the flue gas and reduces the efficiency of the FGD scrubber.
SUMMARY
[0004] Described herein are methods and systems for inhibiting or preventing buildup of crystalline materials in a flue gas desulfurization (FGD) unit. Crystalline materials can accumulate in an FGD unit as a byproduct of chemical desulfurization processes and can adversely impact FGD unit function by, for instance, restricting the flow of the flue gas and thereby reducing the efficiency of the FGD scrubber. Outages required for cleaning FGD scrubber unit(s) are expensive, time consuming, and present significant safety issues. The systems described in the present application include an FGD unit that includes one or more selected bacterial strains disposed therein. It is believed that the bacteria may form a biofilm and/or form a biosurfactant to inhibit or prevent buildup of crystalline materials in the FGD unit. Methods include inoculating an FGD unit with one or more selected bacteria that inhibit or prevent buildup of crystalline materials in the FGD unit. Methods may include periodic reinoculation of the FGD unit.
[0005] In an embodiment, a method for inhibiting crystalline buildup in a flue gas desulfurization (FGD) unit is described. The method includes providing an FGD unit configured for desulfurization of a flue gas, preparing an inoculum that comprises a bacterial strain (e.g., a biosurfactant and/or biofilm producing bacterium) adapted to grow in the FGD unit and to inhibit crystalline formation therein, wherein the inoculum has a selected volume and a selected bacterial cell density in a range of 0.01 weight % (wt %) to 10 wt %, and inoculating the FGD unit with a first amount of the inoculum such that the bacteria are present on one or more surfaces therein so as to inhibit crystalline buildup in the FGD unit. In a preferred embodiment, the bacterial strain in the inoculum comprises one or more of Bacillus subtilis, Bacillus chitinosporus, and variants thereof.
[0006] In another embodiment, the method further includes reinoculating the FGD unit with at least a second amount of the inoculum. In one embodiment, the reinoculating may, for example, occur hourly, daily, or weekly.
[0007] A typical FGD unit includes (1) a vessel with a flue gas inlet and a flue gas outlet and a liquid reservoir containing a desulfurization agent, (2) a recirculation/spray system configured to recirculate and spray the desulfurization agent through the FGD unit, and (3) one or more contact surfaces in the vessel configured for contacting flue gas and the desulfurization agent recirculated and sprayed from the reservoir. The contact surfaces typically include one or more perforated plates intended to provide an increased surface area for contact between the flue gas and the desulfurization agent. The bacterial inoculum may be added to the liquid reservoir containing a desulfurization agent; recirculation of the desulfurization agent throughout the FGD unit also causes to the bacteria to be circulated throughout the unit where it can inhibit crystalline buildup on the sprayers, contact surfaces, etc.
[0008] In another embodiment, a system is described. The system may include a flue gas desulfurization (FGD) unit as described above and a bacterial strain disposed in the FGD unit, wherein the bacterial strain is adapted to grow in the FGD unit and to inhibit crystalline formation therein.
[0009] In yet another embodiment, a system includes a flue gas desulfurization (FGD) unit that includes: a vessel having a flue gas inlet and a flue gas outlet and a first liquid reservoir containing a desulfurization agent, a recirculation/spray system configured to desulfurization agent through the FGD unit, and one or more contact surfaces in the vessel configured for contacting the flue gas and the desulfurization agent recirculated from the reservoir, wherein the one or more contact surfaces include a perforated plate. The system further includes a second liquid reservoir that is outside the FGD unit that contains desulfurization agent, wherein the second liquid reservoir is fluidly connected to the FGD unit via a conduit and a pump, and wherein the second liquid reservoir is configured to replenish the desulfurization agent in the FGD unit. The system further includes a third reservoir containing a selected bacterial strain adapted to grow in the FGD unit, wherein the third reservoir is coupled to the FGD unit via a conduit and a feed system, and wherein the third reservoir is configured for inoculating the FGD unit with the selected bacterial strain adapted to grow in the FGD unit to inhibit crystalline buildup in the FGD unit.
[0010] In one embodiment, the selected bacterial strain may be provided in a dry form. In such an embodiment, the feed system may be configured to mix a predetermined amount of the dry form with an aqueous medium prior to inoculating the FGD unit. In another embodiment, the selected bacterial strain may be provided in a liquid form. In such a case, the feed system may be configured to pump the liquid into the FGD unit (e.g., into the first liquid reservoir) so as to inoculate the FGD unit.
[0011] These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
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United States Patent Application 20170054169
Budge; John R. February 23, 2017
Fuel Cell System And Desulfurization System
Abstract
One embodiment of the present invention is a unique fuel cell system. Another embodiment is a unique desulfurization system. Yet another embodiment is a method of operating a fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and desulfurization systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.
Inventors: Budge; John R.; (Beachwood, OH)
Applicant:
LG Fuel Cell Systems Inc.
North Canton OH
Assignee: LG Fuel Cell Systems Inc.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/689,702, filed Apr. 17, 2015 and titled Fuel Cell System and Desulfurization System, which is a division of application Ser. No. 12/837,084, filed Jul. 15, 2010 and titled Fuel Cell System and Desulfurization System, now U.S. Pat. No. 9,034,527, both of, which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to desulfurization systems and fuel cell systems with desulfurization systems.
BACKGROUND
[0003] Fuel cell systems and desulfurization systems that effectively remove or reduce sulfur content in fuel remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.
SUMMARY
[0004] One embodiment of the present invention is a unique fuel cell system. Another embodiment is a unique desulfurization system. Yet another embodiment is a method of operating a fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and desulfurization systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.
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United States Patent Application 20170050147
Denny; Nicholas R. ; et al. February 23, 2017
Complexation And Removal Of Mercury From Flue Gas Desulfurization Systems
Abstract
A method for the reduction and prevention of mercury emissions into the environment from combusted fossil fuels or off-gases having mercury with the use of hypoiodite is disclosed. The hypoiodite is used for the capture of mercury from the resulting flue gases using a flue gas desulfurization system or scrubber. The method uses hypoiodite in conjunction with a scrubber to capture mercury and lower its emission and/or re-emission with stack gases. The method allows the use of coal as a cleaner and environmentally friendlier fuel source as well as capturing mercury from other processing systems.
Inventors: Denny; Nicholas R.; (Glen Ellyn, IL) ; Keiser; Bruce A.; (Plainfield, IL) ; Carlson; Wayne M.; (Batavia, IL)
Assignee: ECOLAB USA Inc.
St. Paul MN
Description
TECHNICAL FIELD
[0001] This invention relates to the reduction of mercury emissions into the environment from the combustion of coal and/or other carbon-based fuels as well as from other processing systems. The invention relates to the method of capturing mercury from flue gases by flue gas desulfurization systems or scrubbers thereby reducing the levels of toxic mercury, which enables the use of coal as a clean and environmentally friendlier fuel source as well as makes other processing systems more environmentally desirable.
BACKGROUND
[0002] The demand for electricity continues to grow globally. In order to keep stride with the growing demand, coal continues to be a primary source for electricity generation. The burning of coal in power generation plants results in the release of energy, as well as the production of solid waste such as bottom and fly ash, and flue gas emissions into the environment. Emissions Standards, as articulated in The Clean Air Act Amendments of 1990 as established by the U.S. Environmental Protection Agency (EPA), requires the assessment of hazardous air pollutants from utility power plants.
[0003] Conventional coal-fired combustion furnaces and similar devices produce emissions that include pollutants such as mercury. Mercury vapor can contribute to health concerns. At the levels common in the atmosphere, the concentrations of mercury are usually safe. However, mercury can accumulate in ecosystems, for example, as a result of rainfall. Some conventional systems attempt to control mercury emissions with particulate collection devices.
[0004] The primary gas emissions are criteria pollutants (e.g., sulfur dioxide, nitrogen dioxides, particulate material, and carbon monoxide). Secondary emissions depend on the type of coal or fuel being combusted but include as examples mercury, selenium, arsenic, and boron. Coal-fired utility boilers are known to be a major source of anthropogenic mercury emissions in the United States. In December of 2000, the EPA announced its intention to regulate mercury emissions from coal-fired utility boilers despite the fact that a proven best available technology (BAT) did not exist to capture or control the levels of mercury released by the combustion of coal. This has been further complicated by the lack of quick, reliable, continuous monitoring methods for mercury.
[0005] Mercury (elemental symbol Hg) is a metal that melts at 234K (-38.degree. F.) and boils at 630K (674.degree. F.). As such, it can be expected to have a high vapor pressure relative to many metals. The oxidized forms of mercury, Hg.sup.2+ and Hg.sup.+, have much lower vapor pressures and can be captured by fly ash particulates.
[0006] Mercury is found in coals at concentrations ranging from 0.02 to 1 ppm. The mercury is present as sulfides or is associated with organic matter. Upon combustion the mercury is released and emitted into the flue gas as gaseous elemental mercury and other mercury compounds. The mercury appears in the flue gas in both the solid and gas phases (particulate-bound mercury and vapor-phase mercury, respectively). The so-called solid-phase mercury is really vapor-phase mercury adsorbed onto the surface of ash and/or carbon particles. The solid-phase mercury can be captured by existing particle control devices (PCDs) such as electrostatic precipitators (ESPs) and fabric filters (FF), the latter sometimes referred to as baghouses.
[0007] Several control strategies have been developed for the control of mercury emissions from coal-fired boilers. Some of these methods include injection of activated carbon, modified activated carbon, various chemical catalysts, and inorganic sorbents. Unfortunately, none of these strategies removes all the mercury from the flue gas. The efficiencies range from as low as 30% to as high as 80% based on the amount of mercury entering the system with the coal. In addition, these technologies either produce unwanted effects on by-products such as impacting the quality of fly ash, or they generate additional waste streams for the power plant. Both lead to higher operational costs for the power plant. One promising strategy is to take advantage of existing air pollution control devices (APCDs) to augment or to serve as the primary means to remove vapor-phase mercury. Two examples of APCDs are semi-dry and wet scrubbers or flue gas desulfurizer (FGD). Semi-dry FGDs are also known as spray dryer absorbers (i.e., SDAs), circulating dry scrubbers (CDS), or TURBBOSORP.RTM. available from Von Roll.
[0008] Sulfur oxides (SO.sub.x) regulatory compliance mandates the use of at least one of several control strategies. Three such strategies that are used in the US are sorbent injection into the flue gas following by a particulate collection device such as an ESP or a FF, and wet or dry flue gas desulfurizers. At present, about 3% of the coal-fired power plants are using sorbent injection. FGD scrubbing accounts for 85% using wet and 12% using dry scrubber technologies. Wet scrubbers achieve greater than 90% SO.sub.x removal efficiency compared to 80% by dry scrubbing. In wet scrubbers, the flue gas is brought into contact with slurry containing an alkaline source such as lime or limestone. The SO.sub.x is adsorbed into the water and reacts to form calcium sulfite. It has been demonstrated that simultaneous to SO.sub.x capture, wet FGDs can be used to capture vapor-phase mercury from the flue gas.
[0009] Elemental mercury is water-insoluble and is not removed by a wet FGD. In contrast, oxidized mercury in the flue gas is water-soluble and is removed. The Information Collection Request (ICR) mercury data demonstrated that ionic mercury is removed effectively approaching 90% by wet FGDs. Hence, one strategy for mercury capture is to oxidize all the mercury during the burning of the coal and capture the oxidized mercury in the wet scrubber. Work carried out by URS in conjunction with the Department of Energy/National Energy Technology Laboratory (DOE/NETL) investigated just such a strategy. There are two critical technical steps to the implementation of this strategy. The first is the complete oxidation of the vapor-phase mercury exiting the boiler and the coal. URS, among others, is developing strategies and technologies to accomplish this step. To date, they have demonstrated that independent of the coal type, vapor-phase mercury speciation can be shifted to extensively 100% oxidized mercury. The second critical technical step in the implementation of this control strategy is the sorption of the oxidized mercury and removal in the wet scrubber. The problem, identified early on, is that there are reactions occurring in the wet scrubber liquor that reduce oxidized mercury to elemental mercury and lead to "re-emission" or release of elemental mercury into the scrubbed flue gas. The prevention of ionic mercury reduction in wet scrubber liquor has been studied and reported by G. M. Blythe and D. W. DeBerry at URS and others.
[0010] The findings have suggested that complexation of the ionic mercury is one way to reduce or eliminate the generation of elemental mercury in the scrubber. This same study has demonstrated that not all chelants of ionic mercury can accomplish this in a wet FGD. In a recent presentation, plant results of such a chelant, TMT-15, trimercapto-s-triazine, available from Degussa, were inconclusive regarding the prevention of re-emission of mercury across a wet scrubber. Efficient and cost-effective apparatuses and methods for controlling emissions of mercury remain a desirable need in the art whether from combustion sources such as coal plants and cement kilns or other sources such as incinerators used in a variety of activities.
SUMMARY
[0011] In one aspect, a method for reducing mercury emissions is disclosed. In one embodiment, the method includes providing a gas stream comprising mercury and passing the gas stream into a scrubber comprising a scrubber liquor and hypoiodite.
[0012] In one embodiment, the method includes burning a carbonaceous fuel comprising mercury, thereby producing a flue gas, and passing the flue gas into a flue gas scrubber comprising a scrubber liquor and hypoiodite.
[0013] In some embodiments, the hypoiodite is mixed with a carrying agent selected from: limestone slurry, lime slurry, sodium-based alkali solution, trona-based solution, sodium carbonate solution, sodium hydroxide solution, and water.
[0014] In some embodiments, the method also includes mixing an iodine salt and an oxidant to form the hypoiodite. In some embodiments, the oxidant is sodium hypochlorite.
[0015] In some embodiments, the mercury is from combusted coal. In some embodiments, the mercury is from an incinerator. In some embodiments, the mercury is from a cement kiln. In some embodiments, the mercury is from an ore refinery. In some embodiments, the mineral ore processed at the refinery contains phosphorus (such as phosphate). In some embodiments, the mineral ore processed at the refinery contains gold.
[0016] In some embodiments, the scrubber is a wet scrubber selected from spray tower system, a jet bubblers system, and a co-current packed tower system. In some embodiments, the hypoiodite is added to the liquor and then added to the scrubber. In some embodiments, the hypoiodite is added to the scrubber containing the liquor. In some embodiments, the hypoiodite is added to a virgin liquor then added to the scrubber. In some embodiments, the hypoiodite is added to a make-up liquor then added to the scrubber. In some embodiments, the hypoiodite is added to a return liquor then added to the scrubber. In some embodiments, the hypoiodite is added to a reclaimed liquor then added to the scrubber. In some embodiments, the hypoiodite is added to a liquor injected directly into flue gases then added to the scrubber. In some embodiments, the hypoiodite is added to a recirculation loop of the scrubber liquor. In some embodiments, the hypoiodite is added to a low solids return to the scrubber from a scrubber purge stream. In some embodiments, the hypoiodite is added to an aqueous stream introduced into the scrubber. In some embodiments, the hypoiodite is added to a demister. In some embodiments, the hypoiodite is added to a make-up water stream.
[0017] In some embodiments, the mercury is from an incinerator. In some embodiments, the mercury is from a cement kiln.
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