Abstract: A method for treating a gas containing a SO3 component, which comprises adding a sodium carbonate powder having a mean particle diameter of at most 20 &mgr;m to the gas to remove the SO3 component from the gas.

Abstract: The liquid cooling spray in a gas conditioning chamber is modified by the addition of an alkali to scrub sulfuir dioxide and other acid forming gases and a separation unit to remove particles that may contain either unreacted alkali or salts of the acid forming gases. A slurry of fine particles of hydrated lime is injected into the liquid coolant under conditions that result in kernels of controllable size that contain the alkali or salts from reactions with the acid forming gases. The modified cooling liquid provides for a high sulfur dioxide collection efficiency at a low molar ratio of alkali to sulfur, while the specified kernel size range allows fbr efficient removal of the kernels from the gas.

Abstract: A sorbent material is provided comprising a material reactive with sulfur, a binder unreactive with sulfur and an inert material, wherein the sorbent absorbs the sulfur at temperatures between 30 and 200° C. Sulfur absorption capacity as high as 22 weight percent has been observed with these materials.

Abstract: The method of simultaneously reducing carbon dioxide (CO2) emissions and sulfur dioxide (SO2) emissions produced by the combustion of carbon-containing matter in a hearth consists in injecting into the hearth a calcium-based agent, a fraction of which absorbs SO2 after decarbonization, and then, after the flue gases have been subjected to intermediate cooling, in causing them to transit via a first reactor and in putting them in contact therein with the other fraction of the absorbant that has not reacted with SO2 so as to capture CO2 from the flue gases by carbonization, then, in a separator, in extracting the solids contained in the flue gases output from the first reactor so as to subject them to heat treatment in a second reactor in order to extract CO2 therefrom by decarbonization and in order to recycle the resulting regenerated CO2 absorbant to the first reactor.

Abstract: A method for the combined reduction of sulfur dioxide, SO2, and nitrogen oxides, NOx, in the gas stream of a furnace from the combustion of fossil fuels is disclosed. In a narrow gas temperature zone in a furnace, NOx is converted to nitrogen by reaction with a reducing agent such as urea or ammonia with negligible residual ammonia and other reaction pollutants. In about this same temperature zone, SO2 will react with calcium oxide particles, derived from the calcination of lime, Ca(OH)2, or limestone, CaCO3, to form CaSO4 particles. A wide size distribution of aqueous droplets, containing dispersed lime or very fine limestone particles and dissolved urea or ammonia, is injected at the outer edge of the furnace gas zone at which the SO2 and NOx reduction reaction are effective.

Abstract: A process for cleaning flue gases containing ash and sulfur dioxide produced by burning sulfur-containing coal in the combustion chamber of a circulating fluidized-bed firing system includes delivering a particulate SO2 sorbent into the combustion chamber. A mixture including portions of the ash, the reaction product produced in the reaction of the SO2 sorbent with the sulfur dioxide, and unreacted SO2 sorbent is fed from the combustion chamber to a mixing unit. In the mixing unit, water or an aqueous sodium-containing solution is mixed with this mixture and the unreacted SO2 sorbent is converted into a hydration product (for example Ca(OH)2) at a reaction temperature of 60° to 100° and at atmospheric pressure. The ash, the reaction product, and the hydration product is returned from the mixing unit into the combustion chamber, and the hydration product is reactivated to an SO2 sorbent at a combustion-chamber temperature of 700° to 950° C.

Abstract: Provided are a method of treating coal ash by mixing it with water, in which the coal ash and water undergo a temperature difference therebetween while they are mixed; and a method of desulfurization in a coal combustion boiler system, which comprises mixing coal ash that has been separated from a ash collector in the system, with water on the condition that the two undergo a temperature difference therebetween while they are mixed, and circulating the resulting mixture that serves as a desulfurizing agent into the coal combustor in the system. The desulfurization capability of the desulfurizing agent used in the desulfurization method is higher than that of the desulfurizing agent obtained through hydration of coal ash with water or steam.

Abstract: A pollution control apparatus and method to scrub sulfur dioxide uses a lime slurry consisting of small diameter hydrated lime particles injected into the cooling water of a gas cooling tower. The diameter of the lime slurry particles is selected to be less than about 25 microns so that the lime particles substantially dissolve during the evaporative lifetime of the spray droplets. A preferred embodiment of the pollution control apparatus uses an in-line wet grinder and classifier to produce slurry as required.

Abstract: Solid pulverulent reactive composition for the purification of a gas, the said composition comprising sodium bicarbonate and a caking inhibitor for sodium bicarbonate comprising lignite coke and/or a magnesium compound comprising magnesium (hydr)oxide. Process for the purification of a gas, according to which a reactive composition comprising sodium bicarbonate which is substantially devoid of silica is introduced into the gas and the gas is subjected to removal of dust.

Abstract: A method for substantially reducing sulfur-oxide emissions from an asphalt air-blowing process involves adding an emission-reducing additive to the asphalt prior to air-blowing, or early in the air-blowing process, and filtering the flue gases produced in the process. The emission-reducing additive includes at least one metal hydroxide, metal oxide, metal carbonate, or metal bicarbonate, where the metal is sodium, potassium, calcium, magnesium, zinc, copper, or aluminum. The filter is preferably of the fiber-bed type, and removes at least a portion of the sulfur-containing compounds via condensation. The filtered stream of flue gases is subjected to an incineration process before being passed into the atmosphere.

Abstract: A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

Abstract: A method for treating a gas containing a SO3 component, which comprises adding a sodium carbonate powder having a mean particle diameter of at most 20 &mgr;m to the gas to remove the SO3 component from the gas.

Abstract: A method of binding pollutants, such as sulfur dioxide, hydrochloric acid and/or hydrofluoric acid, in flue gas in one or more combustion plants.

Abstract: A composition having sodium bicarbonate, sodium carbonate, and ammonia in the form of ammonium salts is formed by heat treating ammoniacal bicarbonate at a temperature between 20 and 150° C. A method of using the composition includes reacting the composition with a flue gas containing HX acids, where X represents halogens, compounds of the SOx type, or mixtures thereof, or the flue gases may contain NOx compounds.

Abstract: A process is provided for the removal of mercury and sulfur dioxide out a flue gas from, for example, power stations, smelters, waste incineration plants and crematories, by washing the flue gas with an oxidized, chloride-containing washing water, which may be sea water, which has been oxidized by either adding an oxidizing agent, such as sodium hypochlorite, or by passing an electric current through the washing water (which converts the chloride values into chlorine) so that the gaseous mercury is sorbed into the washing water and is converted into mercury (II) chloride complexes and the gaseous sulfur dioxide is sorbed into the washing water and converted into sulfuric acid, and subsequently passing the resulting mercury (II) chloride and sulfuric acid-containing washing water and the flue gas through a bed of calcium carbonate where the sulfuric acid and the calcium carbonate react to form calcium sulfate which is washed off the bed into the washing water.

Abstract: A dust collecting apparatus and method for dedusting a Ca-containing gas using a ceramics filter is provided, in which a filter differential pressure elevation rate is suppressed. A desulferizing agent 103 and a mineral 106 containing MgO are supplied via a hopper 13, 15 a valve 14 and a feeder 16 into a pressurized fluidized-bed combustion furnace 1 together with coal 101 and air 102. A combustion gas 201 is dedusted by a cyclone 2 to become a combustion gas 301, the combustion gas 301 enters a filter container 3a, 3b having a ceramics filter 31a, 31b and is further dedusted. A combustion gas 401 which is dedusted is supplied into a gas turbine 4 to generate power, and combustion gas 501 heats a waste heat recovery boiler 5 which in turn drives a steam turbine 7. The mineral 106 containing MgO is added in the combustion gas 301 which flows in the ceramics filter 31a, 31b. Thereby MgO is added to the combustion gas so that the filter differential pressure elevation rate can be suppressed.

Abstract: A two stage method is described for the removal of NOx and SOx from flue gas. The first stage removes all NOx by sodium sulfite sorbent injection. The second stage removes SOx by sodium bicarbonate injection. The sodium sulfite product formed in the second stage is transferred to the first stage for injection.

Abstract: A method for removing contaminants, such as sulfur dioxide, mercury and hydrochloric acid, out of flue gases is provided, said method including the steps of: treating the flue gases with a reagent, such as sodium carbonate, sodium bicarbonate and ammonium salts or mixtures thereof; selectively dissolving the sodium phosphates produced thereby in water; separating out the solids remaining in suspension in the solution; and crystallizing the purified sodium sulphate present in the above-mentioned solution. The sodium sulfate can be upgraded in glass working furnaces. The reagent can be obtained by heating an intermediate solution containing sodium bicarbonate; sodium carbonate; ammonium bicarbonate and ammonium carbonate, which was obtained from the Solvay process for manufacturing sodium carbonate.