Abstract: Systems and methods for impurity removal to limestone using modifications to the typical calcination process of turning calcium carbonate into calcium oxide. Specifically, substantially increasing the temperature to 1100° C. or higher and increasing soak time can result in reductions in certain undesirable impurities, particularly with regards to lead and lead compounds.

Abstract: The invention relates to a method for reduction of HCl emission from a cement plant based on a treatment of a preheater (1) and/or bypass gas stream, characterized in that a cement raw meal, as a HCl absorber, is dispersed in the gas stream(s) from which HCl is to be removed; the cement raw meal is introduced from a raw mill (6) and/or a silo (8) into a pipe with a up going gas flow; the pipe being arranged in fluid communication at a point after a gas conditioning tower (7) and/or before a particle filter unit (5) and/or in a by-pass line before particle filter (4).

Abstract: Process for treating flue gases in a circulating dry scrubber device wherein flue gases containing pollutants pass to a reactor where said flue gases contact a sorbent comprising high pore volume and high specific surface area slaked lime or hydrated lime being further sent to a particulate control device where said sorbent particles are separated from said flue gases substantially depleted in pollutants and form respectively a flow of flue gases substantially depleted in pollutants and a flow of sorbent particles being recycled and returned to said reactor.

Abstract: Systems and methods for the use of highly reactive hydrated lime (HRH) in circulating dry scrubbers (CDS) to remove sulfur dioxide (SO2) from the flue gas.

Abstract: A system for regulating an amount of fresh lime slurry introduced to a spray dry absorber. The control system includes a controller configured to receive input from a continuous emissions monitoring system (CEMS), a valve in communication with the controller and a spray dry absorber suction pump, the valve adapted to regulate an amount of fresh lime slurry provided to the spray dry absorber suction pump and a valve in communication with the controller and a pre-mix tank, the valve adapted to regulate an amount of fresh lime slurry provided to the pre-mix tank.

Abstract: The present invention concerns a process for purifying a flow of combustion fumes from a clinker production plant comprising the following operating steps: a) removing dust at a temperature comprised between 250 and 400° C. from a flow of combustion fumes exiting from a suspension preheater with formation of a flow of combustion fumes free of dust; b) carrying out on said flow of combustion fumes free of dust a selective catalytic NOx reduction treatment with a reducing agent, with formation of a purified flow of combustion fumes. The present invention also concerns an apparatus for carrying out the aforementioned process.

Abstract: An integrated sorbent injection, heat recovery, and flue gas desulfurization system is disclosed. A dry sorbent is injected into the flue gas upstream of the air heater. This reduces the acid dew point temperature, permitting additional heat energy to be captured when the flue gas passes through the air heater. The flue gas then passes through a desulfurization unit and through a baghouse, where solids are captured. The capture of additional heat energy permits the overall boiler efficiency to be increased while safely operating at a lower flue gas temperature. The integrated system consumes no greater quantity of sorbent than conventional methods but provides the benefit of improved plant heat rate.

Abstract: The invention provides various methods for removing gas phase pollutants by calcining limestone or dolomite using flash calcination to produce a high surface area lime or hydrated lime and directly adding the lime or hydrated lime to a gas stream containing gas phase pollutants. In other methods, the production of an activated sorbent, such as activated carbon, is combined with the production of the high surface area lime or hydrated lime and directly added to a gas stream containing gas phase pollutants. The combination of lime or hydrated lime and an activated sorbent enhances the removal of gas phase pollutants such as those from a coal-fired boiler flue gas.

Abstract: Dry processes, apparatus, compositions and systems are provided for reducing emissions of mercury and optionally sulfur oxides and/or HCl. In an embodiment the copper-based mercury remediation composition comprises a copper ammonium complex having an empirical formula of C2H7CuNO2 or any of the other materials described, which include compositions defined by the formula Cu(NH3)x(lower carboxylate)y, wherein the lower carboxylate is selected from the group consisting of formate, acetate and propionate, x is an integer from 0 to 4, y is an integer from 0 to 2, and x+y is equal to or greater than 1. Sulfur oxides and/or HCl can be additionally reduced by introduction of dolomite hydrate sorbent, and additional mercury remediation chemicals as manganese oxides can be employed. The treated gas stream is treated with a particulate removal device.

Abstract: The disclosure provides an improved means of controlling mercury emissions from coal-fired boiler applications. Specifically, the disclosure comprises a static mixing device placed in the flue gas stream. The static mixing device can enhance dispersion of injected sorbents in the flue gas, resulting in improved mercury capture at a lower sorbent injection rate.

Abstract: Methods for reducing the acidic gas content of effluent gas streams are disclosed. The methods generally involve reducing the acidic gas content of combustion gases passing through a duct by injecting hydrated lime or pulverized quicklime into the duct by use of a shrouded injector which reduces the incidence of occlusion of the injector.

Abstract: The preparation of nano-oxide coated adsorbent, which is useful for treatment of toxic gases, by coating of composite materials containing hydrotalcite over ceramic monolithic substrates. Oxides and salts of metals are reacted in a known manner to prepare hydrotalcites or mixed metal layered hydroxides such as Mg—Al, Ca—Al, Zn—Al, Zn—Cr type possessing positive layer charge, from which a stable gel is prepared by adding swellable clay, e.g., montmorillonite etc. in different hydrotalcite:clay ratio in an aqueous medium and homogenizing the same with high speed homogenizer and ultrasonicator in a high intensity ultrasonic processor. The gel is dip-coated over cordierite/mulite honey-comb monolithic supports. The dip-coated monoliths are dried and calcined to develop the alumino-silicate supported nano-oxide coats over honey-comb ceramic substrates for carrying out adsorption of H2S and SO2 gas in a He flow in various flow rates at 400 to 1000° C. temperature in a cylindrical quartz tube.

Abstract: Dry processes, apparatus, compositions and systems are provided for reducing emissions of sulfur oxides, and sulfur dioxide in particular, and/or HCl in a process employing a combination of a dolomite hydrate sorbent and a sorbent doping agent administered to achieve coverage of a three-dimensional cross section of a passage carrying SOx and/or HCl —containing gases with a short but effective residence time at a temperature effective to provide significant sulfur dioxide and/or HCl reductions with high rates of reaction and sorbent utilization. The once-through, dry process can advantageously introduce the sorbent and sorbent doping agent dry or preferably as a slurry to enable uniform treatment. Preferred sorbent doping agents include water-soluble or water-dispersible copper and/or iron compositions which can be heated to an active form in situ by the flue gases being treated.

Abstract: An air quality control system (AQCS) useful for treating flue gas, such as flue gas produced by a fossil fuel fired boiler, is described. In addition to flue gas treatment, the AQCS provides for air preheater flue gas outlet flue gas temperature reduction and air preheater corrosion prevention while reducing capital costs, increasing reliability and increasing operating flexibility with regard to fuel selection.

Abstract: A method for the removal of CO2, SOx and NOx in a single-step process is described herein. A gas mixture is directed to a carbonator. A carbonaceous material and calcium sorbent is then injected into the carbonator to remove the CO2, SOx and NOx. A calciner is provided to regenerate the calcium sorbent. The unreacted carbonaceous material is used to fuel the calciner.

Abstract: Methods and systems for the removal of SO2 from waste combustion flue gas are described herein. One such system for removing SO2 from waste combustion flue gas containing SO2 uses a semi-dry desulfurization system for contacting the flue gas with a solvent moistened absorption material. Thereafter, a recirculated water quench is used for contacting the flue gas with recirculated water at a relatively low pH, followed by a condenser used for contacting the flue gas with a water spray. Additionally, a NaOH supply for supplying NaOH to the condenser and an oxidizing catalyst supply for supplying an oxidizing catalyst to the condenser, are likewise used to produce cleaned flue gas for release to the atmosphere.

Abstract: A method for combustion of a fuel and treatment of the resulting flue gas includes: combusting a fuel to produce a hot flue gas stream containing at least carbon dioxide (CO2) and sulfur dioxide (SO2), bringing the flue gas stream into contact with solid calcium oxide (CaO) in a carbonation reactor operating at a temperature at which CO2 in the flue gas reacts with CaO to form solid calcium carbonate (CaCO3), heating CaCO3 in a calcination reactor operating at a temperature at which CaCO3 is converted to CaO and CO2, and recirculating CaO formed in the calcination reactor back to the carbonation reactor. Heating can be at least partially effected by indirect heat exchange with hot flue gas from the combustion. Flue gas used for the indirect heat exchange can be subsequently subjected to dry desulfurization before it is brought into contact with CaO in the carbonation reactor.

Abstract: Methods of reducing emissions levels during steady-state conditions are disclosed for use with a dry scrubber desulfurization system. A dry calcium hydroxide powder is injected into the gas flowpath and watered in the spray dryer absorber. The resulting slurry is then deposited on the filter bags in the baghouse. This can be done at lower temperatures than the spray dryer absorber would otherwise be operable, enabling desulfurization to occur earlier in the combustion process, particularly during startup of a cold boiler at ambient temperature. The operation of the boiler can also be backed up, made up, trimmed, or augmented depending on various operating scenarios.

Abstract: Methods of reducing emissions levels during upset periods such as startup are disclosed for use with a dry scrubber desulfurization system. A dry calcium hydroxide powder is injected into the gas flowpath and hydrated in the spray dryer absorber. The resulting hydrated powder is then deposited on the filter bags in the baghouse. This can be done at lower temperatures than the spray dryer absorber would otherwise be operable, enabling desulfurization to occur earlier in the combustion process, such as during startup of a cold combustion system at ambient temperature. The operation of the combustion system can also be backed up, made up, trimmed, or augmented depending on various operating scenarios.

Abstract: A process for capturing undesirable combustion products produced in a high temperature combustion system in which a carbonaceous fuel is utilized. Very finely sized particles of alkaline earth carbonates or hydroxides, with or without added ground ash, are provided in slurry form and are injected into the high temperature zone of a furnace. The particles flash calcine to provide substantially unagglomerated particles having a particle size of less than about 0.5 microns to capture and neutralize SOx, NOx, and toxic metals present in the combustion products.

Abstract: A process for producing a purified synthesis gas stream from a feed synthesis gas stream comprising besides the main constituents carbon monoxide and hydrogen also hydrogen sulphide, HCN and/or COS, the process comprising the steps of: (a) contacting one part of the feed synthesis gas stream with a water gas shift catalyst in a shift reactor in the presence of water and/or steam to react at least part of the carbon monoxide to hydrogen and carbon dioxide, to obtain a shifted synthesis gas stream enriched in hydrogen and in carbon dioxide; (b) contacting another part of the feed gas stream with a hydrolysis catalyst in the presence of water to remove HCN and/or COS to obtain a hydrolysed synthesis gas stream depleted in HCN and/or COS; (c) removing H2S from the shifted synthesis gas stream and from the hydrolysed synthesis gas stream by contacting these gas streams in a H2S-removal zone with an aqueous alkaline washing liquid to obtain a H2S-depleted synthesis gas stream and a sulphide-comprising aqueous strea

Abstract: A process for treating a flue gas is provided. The process comprises burning an amount of elemental magnesium in the flue gas, optionally to produce magnesium oxide and elemental carbon. A process for regenerating elemental magnesium from magnesium oxide is also provided, in addition to processes for producing energy from the elemental carbon.

Abstract: A circulating dry scrubber flue gas desulfurization system is disclosed. Hydrated lime is injected into the flue gas upstream of the CDS vessel. The flue gas then passes through a baghouse, where solids are captured. At least a portion of the solids are recycled. The recycle path runs from the baghouse to a splitter, where the solids are divided between the injection points. No distribution box is needed, which permits lowering the height and/or restructuring the location of many components of the system, reducing costs as well as improving or maintaining removal of combustion byproducts from the flue gas.

Abstract: Sorbent compositions containing halogen and calcium are added to coal to mitigate the release of sulfur and/or other harmful elements, including mercury, into the environment during combustion of coal containing natural levels of mercury.

Abstract: The disclosure provides an improved means of controlling mercury emissions from coal-fired boiler applications. Specifically, the disclosure comprises a static mixing device placed in the flue gas stream. The static mixing device can enhance dispersion of injected sorbents in the flue gas, resulting in improved mercury capture at a lower sorbent injection rate.

Abstract: An air quality control system (AQCS) useful for processing a gas stream, such as a flue gas stream emitted from a fossil fuel fired boiler, for at least partial removal of acidic and like pollutants therefrom. The air quality control system includes a CDS reactor useful using a reducing agent slurry.

Abstract: A process for burning coal or other carbonaceous fuels captures sulfur and other undesirable compounds are captured and retained in non-reactive ceramic-like form after the combustion phase. The process involves addition of multiple element alkali powders and/or sorbents preferably containing oxidizing anions such as nitrates and nitrites, preferably based on calcium. In various embodiments, the remediation materials when applied in a complex powder and/or liquid containing multiple elements, result in higher sulfur capture than the materials would otherwise achieve on an individual basis. In a preferred embodiment, the sorbents contain elements that minimize or lower the melting point of the ash. This leads to lowered cohesiveness and toughness of the ash so that less ash builds up on the boiler and better heat transfer is obtained.

Abstract: Sorbent compositions containing halogen and calcium are added to coal to mitigate the release of sulfur and/or other harmful elements, including mercury, into the environment during combustion of coal containing natural levels of mercury.

Abstract: The present invention relates to a method for combined SO2 and CO2 removal from flue gas, which includes removing both CO2 and SO2 in a primary fractionation column and two polishing columns, the method comprising: a) hot flue as pretreatment, including flue gas SO3 removal by dry sorbent injection; b) compressing the treated hot flue gas by a multi-stage compressor; c) separation of CO2, SO2 and non-condensable gases; d) subjecting the CO2 and SO2 to separate polishing columns; and e) combining streams from the primary fractionation column and the two polishing columns for power recovery.

Abstract: A process for the energy efficient, environmentally friendly recovery of liquid and gaseous products from solid or semi-solid hydrocarbon resources, in particular, oil shale or tar sands. The process involves non-oxidative pyrolysis to recover fluid energy values, oxidative combustion to recover energy values as recoverable heat, and environmental sequestration of gases produced.

Abstract: Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

Abstract: A method and system for desulfurization comprising first and second metal oxides; a walled enclosure having an inlet and an exhaust for the passage of gas to be treated; the first and second metal oxide being combinable with hydrogen sulfide to produce a reaction comprising a sulfide and water; the first metal oxide forming a first layer and the second metal oxide forming a second layer within the walled surroundings; the first and second layers being positioned so the first layer removes the bulk amount of the hydrogen sulfide from the treated gas prior to passage through the second layer, and the second layer removes substantially all of the remaining hydrogen sulfide from the treated gas; the first metal oxide producing a stoichiometrical capacity in excess of 500 mg sulfur/gram; the second metal oxide reacts with the hydrogen sulfide more favorably but has a stoichometrical capacity which is less than the first reactant; whereby the optimal amount by weight of the first and second metal oxides is achieved

Abstract: The present invention relates to a method for combined SO2 and CO2 removal from flue gas, which includes removing both CO2 and SO2 in a primary fractionation column and two polishing columns, the method comprising: a) hot flue as pretreatment, including flue gas SO3 removal by dry sorbent injection; b) compressing the treated hot flue gas by a multi-stage compressor; c) separation of CO2, SO2 and non-condensable gases; d) subjecting the CO2 and SO2 to separate polishing columns; and e) combining streams from the primary fractionation column and the two polishing columns for power recovery.

Abstract: An acid gas sorbent composition is disclosed. The composition comprises a compound having the following formula: (SiO2)x(OH)yF.B wherein F optionally exists and said F is at least one of the following: a functionalized organosilane, a sulfur-containing organosilane, or an amine-containing organosilane; and wherein B is a hygroscopic solid at a preferred water to solid molar ratio of about 0.1 to about 6, and more particularly, B is a basic inorganic solid including, but not limiting to, alkali or alkali-earth metal oxides, hydroxides, carbonates, or bicarbonates, containing at least one of the following metal cations: calcium, magnesium, strontium, barium, sodium, lithium, potassium, cesium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, scandium, ytterbium, yttrium, or erbium; wherein the molar ratio of y/x is equal to about 0.01 to about 0.5.

Abstract: Sorbent compositions containing halogen and calcium are added to coal to mitigate the release of sulfur and/or other harmful elements, including mercury, into the environment during combustion of coal containing natural levels of mercury.

Abstract: Methods for reducing the acidic gas content of effluent gas streams are disclosed. The methods generally involve reducing the acidic gas content of combustion gases passing through a duct by injecting hydrated lime or pulverized quicklime into the duct by use of a shrouded injector which reduces the incidence of occlusion of the injector.

Abstract: A two-step process for the cleaning of a stream of flue gas, containing noxious acidic compounds, by means of a quantity of basic sodium reagent, wherein the quantity of basic sodium reagent is injected in a secondary stream diverted from the main stream wherein it reacts in a first step with the noxious acidic compounds contained in the secondary stream during a pre reaction period, resulting in pre-reacted basic reagent, un-reacted basic reagent and partially cleaned secondary stream of flue gas; and wherein after the pre reaction period, the partially cleaned secondary stream comprising the quantity of pre reacted basic sodium reagent is reintroduced in the main stream, the pre-reacted reagent and un-reacted reagent further reacting in a second step with at least part of the remaining noxious acids left in the partially cleaned secondary stream of flue gas.

Abstract: In a method for reducing lime consumption in DFGD systems, a slaker is provided wherein lime and water is introduced to produce a slaked lime slurry. The slurry is introduced into a spray dryer wherein the slurry is atomized. A flue gas stream is also introduced into the spray dryer and reacts with the atomized slurry, causing calcium sulfate and sulfite, as well as unreacted lime particulate to form. A portion of the particulate is filtered and sent back in a substantially dry form to the slaker to form part of the slurry.

Abstract: A particulate desulfurization material includes one or more nickel compounds, a zinc oxide support material, and one or more alkali metal compounds wherein the nickel content of the material is in the range 0.3 to 10% by weight and the alkali metal content of the material is in the range 0.2 to 10% by weight. A method of making the desulfurization material includes the steps: (i) contacting a nickel compound with a particulate zinc support material and an alkali metal compound to form an alkali-doped composition, (ii) shaping the alkali-doped composition, and (iii) drying, calcining, and optionally reducing the resulting material. The desulfurization material may be used to desulfurize hydrocarbon gas streams with reduced levels of hydrocarbon hydrogenolysis.

Abstract: Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

Abstract: Process for producing sodium bicarbonate for purifying flue gases, according to which an aqueous solution containing sodium sulfate is subjected to electrodialysis to produce a sodium hydroxide solution and a sodium bisulfate solution, the sodium hydroxide solution being carbonated in order to obtain sodium bicarbonate.

Abstract: An air quality control system (AQCS) (4) useful for processing a gas stream (DG), such as a flue gas stream emitted from a fossil fuel fired boiler (2), combustion process or the like, for at least partial removal of acidic and like contaminants. The air quality control system (4) includes a plurality of integrated components (12) equipped with both a dry scrubber system (8) and a fabric filter (10). The air quality control system (4) such as described possesses increased “turn down” capabilities thus increasing the efficiency thereof.

Abstract: Sorbent compositions containing halogen and calcium are added to coal to mitigate the release of sulfur and/or other harmful elements, including mercury, into the environment during combustion of coal containing natural levels of mercury.

Abstract: An absorbing tower provided with plural spray headers (3) which each have a plurality of spray nozzles (5) and are arranged in a multi-stage state in the flow direction of exhaust gas, in which an absorption liquid containing a slurry of limestone or lime is sprayed through the nozzles (5) to absorb and remove sulfur oxide contained in exhaust gas, wherein each spray nozzle (5) is of an annular spray type (a hollow cone type) and the spray nozzles (5) in the neighborhood of the tower wall have such a structure that the fluid is sprayed radially at spray angles of 50 to 80° with the direction counter to the flow of exhaust gas as the center, while the nozzles (5) in the central part of the tower have such a structure that the fluid is sprayed radially at spray angles of 80 to 130° with the direction counter to the flow thereof as the center.

Abstract: A process for treating a flue gas is provided. The process comprises burning an amount of elemental magnesium in the flue gas, optionally to produce magnesium oxide and elemental carbon. A process for regenerating elemental magnesium from magnesium oxide is also provided, in addition to processes for producing energy from the elemental carbon.

Abstract: The invention provides various methods for removing gas phase pollutants by calcining limestone or dolomite using flash calcination to produce a high surface area lime or hydrated lime and directly adding the lime or hydrated lime to a gas stream containing gas phase pollutants. In other methods, the production of an activated sorbent, such as activated carbon, is combined with the production of the high surface area lime or hydrated lime and directly added to a gas stream containing gas phase pollutants. The combination of lime or hydrated lime and an activated sorbent enhances the removal of gas phase pollutants such as those from a coal-fired boiler flue gas.

Abstract: Disclosed herein is an apparatus and methods for decontaminating syngas generated in a fluidized-bed gasifier wherein metal contaminants, inter alia, alkali metals, halogens, particulates, and transition metals and sulfur containing contaminants are removed prior to the catalytic thermal cracking of tar and ammonia. Further disclosed is an apparatus and methods for removing ammonia from syngas.

Abstract: Sorbent compositions containing halogen and calcium are added to coal to mitigate the release of sulfur and/or other harmful elements, including mercury, into the environment during combustion of coal containing natural levels of mercury.

Abstract: A process for capturing undesirable combustion products produced in a high temperature combustion system. Very finely sized particles of alkaline earth carbonates or hydroxides, with or without added ground fly ash, are provided in slurry form and are injected into the high temperature zone of a furnace. The particles flash calcine to provide substantially unagglomerated particles having a particle size of less than about 0.5 microns to capture and neutralize SOx, NOx, and toxic chemicals.

Abstract: Sorbent components containing calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents are added to the coal ahead of combustion and/or are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.