Abstract: In order to heighten the recovery of activated carbon by separation in a flotation device and stably inhibit mercury from being re-emitted in a desulfurization/absorption tower and from coming into gypsum to be recovered, a method is provided, the method comprising: adding activated carbon to an absorption liquid to be sprayed into the desulfurization/absorption tower to thereby remove mercury components from the flue gas simultaneously with desulfurization of the flue gas; sending the absorption liquid used for the desulfurization to the flotation device to thereby form a foam bubble layer; reducing the drainage volume so that the physical properties of the bubble layer are within given ranges, in such an amount that the concentration of chlorine ions in the absorption liquid does not exceed a given value; and simultaneously adding Ca and/or Mg ions and a frothing agent to the absorption liquid.

Abstract: In order to heighten the recovery of activated carbon by separation in a flotation device and stably inhibit mercury from being re-emitted in a desulfurization/absorption tower and from coming into gypsum to be recovered, a method is provided, the method comprising: adding activated carbon to an absorption liquid to be sprayed into the desulfurization/absorption tower to thereby remove mercury components from the flue gas simultaneously with desulfurization of the flue gas; sending the absorption liquid used for the desulfurization to the flotation device to thereby form a foam bubble layer; reducing the drainage volume so that the physical properties of the bubble layer are within given ranges, in such an amount that the concentration of chlorine ions in the absorption liquid does not exceed a given value; and simultaneously adding Ca and/or Mg ions and a frothing agent to the absorption liquid.

Abstract: A method of recovering carbon dioxide, includes bringing gas to be processed containing carbon dioxide (CO2) and oxygen into contact with the CO2-absorbing solution in an absorption column to form a CO2-rich solution; circulating the solution in a regeneration column to thermally release and recover CO2 and recirculating the absorbing solution as a CO2-poor solution inside the absorption column; and performing heat exchange between the solution being delivered from the absorption column to the regeneration column and the solution recirculated from the regeneration column to the absorption column, wherein an alkanolamine aqueous solution containing a silicone oil and/or an organosulfur compound is added to the solution inside the absorption column and/or the solution recirculated from the regeneration column to the absorption column to adjust the composition of the absorbing solution inside the absorption column.

Abstract: A desulfurization device releases exhaust gas into the atmosphere without reduction in CO2 recovery rate and without mercury components. Because the absorbent of the desulfurization device is drawn from an absorbent reservoir by a circulating pump and sprayed through spray nozzles into a desulfurization-absorption unit and is mainly circulated outside the wall of a water seal tube by a stirrer in the absorbent reservoir, the flow of the absorbent that falls from the desulfurization-absorption unit into the water seal tube flows in a single direction from top to bottom and hinders the ascension of gas bubbles. Intermixing of the gas for oxidizing the sulfur dioxide with the desulfurization device exhaust gas is thereby prevented, efficient CO2 recovery is possible without reduction in the CO2 concentration recovered from the exhaust gas after desulfurization and mercury in the combustion exhaust gas is absorbed in the absorbent of the desulfurization device.

Abstract: A method of recovering carbon dioxide, including bringing gas to be processed containing carbon dioxide (CO2) and oxygen into contact with the CO2-absorbing solution according to Claim 1 in an absorption column to form a CO2-rich solution; subsequently circulating the solution in a regeneration column to thermally release and recover CO2 and recirculating the absorbing solution as a CO2-poor solution inside the absorption column; and performing heat exchange between the solution being delivered from the absorption column to the regeneration column and the solution recirculated from the regeneration column to the absorption column, wherein an alkanolamine aqueous solution containing a silicone oil and/or an organosulfur compound represented by the Formula (A) or (B) is added to the solution inside the absorption column and/or the solution recirculated from the regeneration column to the absorption column to adjust the composition of the absorbing solution inside the absorption column so as to include the alkan

Abstract: After adjusting an exhaust gas temperature at an exit of a heat recovery unit (11) of an exhaust gas treating apparatus to not more than a dew point temperature of sulfur trioxide (SO3), a heavy metal adsorbent is supplied from a heavy metal adsorbent supply unit (16) disposed in an exhaust gas at an entrance of a precipitator (4) or an intermediate position within the precipitator (4), and the exhaust gas containing the heavy metal adsorbent is supplied into the precipitator (4). Preferably at this stage, the heavy metal adsorbent is supplied into the exhaust gas at the entrance of the precipitator (4) 0.1 seconds after the exhaust gas temperature at the exit of the heat recovery unit (11) has been adjusted to not more than the dew point temperature of SO3.

Abstract: An apparatus for removing of traces of toxic substances from exhaust gas, comprising, disposed in sequence from the upstream side in a flow channel of exhaust gas emitted from combustion equipment, a denitration unit including a denitration catalyst layer capable of removing nitrogen oxides from the exhaust gas and capable of oxidizing metallic mercury; an air preheater adapted for heat exchange between air for combustion in the combustion equipment and the exhaust gas; a dust removal unit having a bag filter containing a catalyst for metallic mercury oxidation; and a desulfurization unit for removing sulfur oxide from the exhaust gas. The bag filter may be disposed in advance of the desulfurization unit. Thus, there can be provided an apparatus for removing of traces of toxic substances from exhaust gas that is stable over a prolonged period of time and is highly reliable; and provided a method of operating the same.

Abstract: A system is provided that prevents inhibition of adsorption of Hg and other heavy metals by activated carbon or other heavy metal adsorbent due to prior adsorption of sulfur trioxide (SO3) in an exhaust gas containing SO3. As it has been found that while SO3 is adsorbed, the adsorption of SO3 precedes the adsorption of Hg and other heavy metals onto activated carbon, a basic substance injection system is disposed along an exhaust gas flow channel at an upstream side of an activated carbon injection system, thereby attaining effective removal of Hg and other heavy metals from the exhaust gas by adsorption thereof onto surface pores of the activated carbon. The SO3 concentration after removal by basic substance conversion is computed from the SO3 concentration before removal, and the activated carbon injection rate can be controlled based on the concentration after removal.

Abstract: A method and apparatus for treating an exhaust gas comprising heavy metals, wherein the apparatus comprises a heat recovery unit, recovering exhaust gas heat at an exit of the air preheater; a precipitator, collecting soot/dust contained in an exhaust gas at an exit of the heat recovery unit; a wet flue gas desulfurizer, removing sulfur oxides contained in the exhaust gas at the exit of the precipitator; and a reheater, heating the exhaust gas at the exit of the wet flue gas desulfurizer. Each of the heat recovery unit and the reheater has a heat exchanger tube, and a circulation line is disposed to connect the heat exchanger tubes. A sulfur trioxide (SO3) removing agent is supplied to the upstream side of the heat recovery unit, and the temperature of the exhaust gas at the exit of the heat recovery unit is adjusted to not more than a dew point of sulfur trioxide.

Abstract: Methods and apparatus for pollution control which are well suited for use in a coal power plant are described. Ash is collected and injected into the flue gas stream at a location upstream of a cooling module. The ash acts as an absorbent and/or reactant material onto which condensate may condense. By re-introducing ash to keep the condensation forming wet areas within the system, lower cost materials which are less corrosion resistant than needed for wet operating conditions can be used. Mercury recovery and SO3 removal is facilitated by the cooling process and re-introduction of collected ash. Activated carbon and/or an alkali absorbent material may be added. Use of a dry ESP and/or fabric filter as opposed to a wet ESP for particulate collection leads to cost benefits. Energy recovered by the cooling of the flue gas may be re-used to heat turbine condensate leading to improved energy efficiency.

Abstract: A system is provided that prevents inhibition of adsorption of Hg and other heavy metals by activated carbon or other heavy metal adsorbent due to prior adsorption of sulfur trioxide (SO3) in an exhaust gas containing SO3. As it has been found that while SO3 is adsorbed, the adsorption of SO3 precedes the adsorption of Hg and other heavy metals onto activated carbon, a basic substance injection system is disposed along an exhaust gas flow channel at an upstream side of an activated carbon injection system, thereby attaining effective removal of Hg and other heavy metals from the exhaust gas by adsorption thereof onto surface pores of the activated carbon. The SO3 concentration after removal by basic substance conversion is computed from the SO3 concentration before removal, and the activated carbon injection rate can be controlled based on the concentration after removal.

Abstract: The following devices are successively disposed in the following order from an upstream side to a downstream side in an exhaust gas duct of a combustion apparatus: an air preheater, preheating combustion air for use in an exhaust gas treating apparatus; a heat recovery unit, recovering exhaust gas heat at an exit of the air preheater; a precipitator, collecting soot/dust contained in an exhaust gas at an exit of the heat recovery unit; a wet flue gas desulfurizer, removing sulfur oxides contained in the exhaust gas at the exit of the precipitator; and a reheater, heating the exhaust gas at the exit of the wet flue gas desulfurizer. Each of the heat recovery unit and the reheater has a heat exchanger tube, and a circulation line is disposed to connect the heat exchanger tubes. A sulfur trioxide (SO3) removing agent is supplied to the upstream side of the heat recovery unit, and the temperature of the exhaust gas at the exit of the heat recovery unit is adjusted to not more than a dew point of sulfur trioxide.

Abstract: After adjusting an exhaust gas temperature at an exit of a heat recovery unit (11) of an exhaust gas treating apparatus to not more than a dew point temperature of sulfur trioxide (SO3), a heavy metal adsorbent is supplied from a heavy metal adsorbent supply unit (16) disposed in an exhaust gas at an entrance of a precipitator (4) or an intermediate position within the precipitator (4), and the exhaust gas containing the heavy metal adsorbent is supplied into the precipitator (4). Preferably at this stage, the heavy metal adsorbent is supplied into the exhaust gas at the entrance of the precipitator (4) 0.1 seconds after the exhaust gas temperature at the exit of the heat recovery unit (11) has been adjusted to not more than the dew point temperature of SO3.

Abstract: An exhaust smoke processing system comprises air preheater for heating combustion air by exhaust smoke discharged from a boiler, a heat recoverer for heating a heat medium by exhaust smoke discharged from the air preheater, a dust collector for collecting soot and dust in exhaust smoke discharged from the heat recoverer, a wet-type exhaust smoke processing apparatus for processing exhaust smoke discharged from the dust collector, a reheater for heating exhaust smoke discharged from the wet-type exhaust smoke processing apparatus by the heat medium, and a heat medium circulation pipe passage for circulating the heating medium between the reheater and the heat recoverer. the system measures a heavy metal concentration in the exhaust smoke and adjusts the temperature of exhaust smoke at an outlet of the heat recoverer such that the measured value falls within a predetermined range.

Abstract: An apparatus for removing of traces of toxic substances from exhaust gas, comprising, disposed in sequence from the upstream side in a flow channel of exhaust gas emitted from combustion equipment, a denitration unit including a denitration catalyst layer capable of removing nitrogen oxides from the exhaust gas and capable of oxidizing metallic mercury; an air preheater adapted for heat exchange between air for combustion in the combustion equipment and the exhaust gas; a dust removal unit having a bag filter containing a catalyst for metallic mercury oxidation; and a desulfurization unit for removing sulfur oxide from the exhaust gas. The bag filter may be disposed in advance of the desulfurization unit. Thus, there can be provided an apparatus for removing of traces of toxic substances from exhaust gas that is stable over a prolonged period of time and is highly reliable; and provided a method of operating the same.

Abstract: Methods and apparatus for pollution control which are well suited for use in a coal power plant are described. Ash is collected and injected into the flue gas stream at a location upstream of a cooling module. The ash acts as an absorbent and/or reactant material onto which condensate may condense. By re-introducing ash to keep the condensation forming wet areas within the system, lower cost materials which are less corrosion resistant than needed for wet operating conditions can be used. Mercury recovery and SO3 removal is facilitated by the cooling process and re-introduction of collected ash. Activated carbon and/or an alkali absorbent material may be added. Use of a dry ESP and/or fabric filter as opposed to a wet ESP for particulate collection leads to cost benefits. Energy recovered by the cooling of the flue gas may be re-used to heat turbine condensate leading to improved energy efficiency.

Abstract: Disclosed are a method and an apparatus for treating an effluent containing ammonia in which method and apparatus N2O concentration in the gas at the outlet of a catalyst tower does not rise to a high level even when the NH3 concentration in the effluent was reduced and the amount of hazardous substances formed is small; in the method and apparatus, an NH3-containing effluent A and a carrier gas (steam C and combustion gas F) are contacted in stripping tower 7 to transfer the NH3 from the NH3-containing effluent to a gas phase, the gas containing the generated NH3 is heated with pre-heater 19 and then contacted with catalyst layer 13 placed in catalyst tower 12 to decompose the NH3 into nitrogen and water; and at that time, the oxygen concentration in the gas to be introduced into catalyst tower 12 and the N2O concentration in the gas discharged from catalyst tower 12 are determined by measuring instruments 21 and 22, respectively, and the oxygen concentration in the gas to be introduced into catalyst tower 1

Abstract: An exhaust smoke processing system capable of economically removing heavy metal, comprising a air preheater 3 for heating combustion air by exhaust smoke discharged from a boiler 1, a heat recoverer 11 for heating a heat medium by exhaust smoke discharged from the air preheater 3, a dust collector 4 for collecting soot and dust in exhaust smoke discharged from the heat recoverer 11, a wet-type exhaust smoke processing apparatus for processing exhaust smoke discharged from the dust collector 4, a reheater 13 for heating exhaust smoke discharged from the wet-type exhaust smoke processing apparatus by the heat medium, and a heat medium circulation pipe passage 15 for circulating the heating medium between the reheater 13 and the heat recoverer 11, wherein the heating medium circulation pipe 15 is provided with temperature control means which measures a heavy metal concentration in exhaust smoke discharged from any one or more of the dust collector 4, the wet-type exhaust smoke processing apparatus 6 and the rehe

Abstract: Disclosed are methods and apparatuses for treating an ammonia-containing effluent in which the amount of hazardous substances such as NOx formed at the time of starting the operation of the apparatus or even at the time when the concentration of ammonia (NH3) in the gas to be subjected to an NH3 decomposing step (described below) was changed is extremely small; in which method an NH3-containing effluent A and vapor (carrier gas) C are contacted in stripping tower 7 to transfer the NH3 from the effluent to a gas phase, a gas containing the NH3 stripped in the tower is heated with pre-heater 1 and then contacted with catalyst 13 to decompose the NH3 into nitrogen and water, the concentration of the NOx (or N2O) contained in the gas resulted at the NH3 decomposing step is determined, and one or more of parameters (a) the amount of the effluent to be supplied to the stripping step, (b) the concentration of the NH3 contained in the effluent, and (c) the flow rate of the NH3-containing gas contacted with the cataly

Abstract: Disclosed are a method and an apparatus for treating an effluent containing ammonia in which method and apparatus N2O concentration in the gas at the outlet of a catalyst tower does not rise to a high level even when the NH3 concentration in the effluent was reduced and the amount of hazardous substances formed is small; in the method and apparatus, an NH3-containing effluent A and a carrier gas (steam C and combustion gas F) are contacted in stripping tower 7 to transfer the NH3 from the NH3-containing effluent to a gas phase, the gas containing the generated NH3 is heated with pre-heater 19 and then contacted with catalyst layer 13 placed in catalyst tower 12 to decompose the NH3 into nitrogen and water; and at that time, the oxygen concentration in the gas to be introduced into catalyst tower 12 and the N2O concentration in the gas discharged from catalyst tower 12 are determined by measuring instruments 21 and 22, respectively, and the oxygen concentration in the gas to be introduced into catalyst tower 1