622results about "Alkali metal sulfides/polysulfides" patented technology

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.

A flue gas control system of a coal combustion boiler comprises an HCl atomizer that sprays hydrogen chloride to flue gas from a coal combustion boiler that uses coal as a fuel; NOx removing apparatus that removes nitrogen oxides by ammonia denitration by adding ammonia to the flue gas after spraying hydrogen chloride and oxidizes mercury; an air preheater that recovers heat in the gas after removal of nitrogen oxides; a precipitator that removes particulates in the gas; an activated carbon atomizer that sprays activated carbon into the gas after particulate collection; a bag filter that collects activated carbon having adsorbed mercury; a desulfurizer that removes sulfur oxides in the flue gas after removal of activated carbon; a stack that discharges the gas which has undergone desulfurization to outside; and an ORP meter that measures an oxidation reduction potential for feeding air to a slurry absorbent in the desulfurizer.

A water stream containing hardness minerals is subjected to a water treatment process using an alkali agent to precipitate the hardness minerals and to produce a softened water stream is used to create an integrated water treatment and flue gas desulfurization process. Thereafter, the softened, alkaline water stream is utilized in a scrubber to scrub a flue gas containing sulfur dioxide to produce a sulfur-lean flue gas. The invention may be applied to a steam-based bitumen recovery operation where bitumen, sour produced gas or other sulfur containing fuels are burned for producing steam for bitumen recovery. More specifically, the associated produced water from the bitumen recovery process may be softened for re-use and for utilization as a scrubbing agent for high-sulfur containing flue gas arising from the steam generators. The process provides an economically favorable process while minimizing waste disposal requirements.

The gaseous effluent flowing in through line 1 is contacted in absorption zone ZA with the liquid absorbent solution flowing in through line 9. The gaseous effluent depleted in acid compounds is discharged through line 2. The absorbent solution laden with acid compounds is discharged through line 3. The absorbent solution once laden with acid compounds comprises two phases: a first phase poor in acid compounds and a second phase rich in acid compounds. The two phases are separated in zone ZS. The first phase is recycled through lines 5 and 9 to absorption zone ZA. The second phase is fed through line 4 into regeneration zone ZR. In zone ZR, the acid compounds are separated from the absorbent solution. The acid compounds are discharged through line 7. The regenerated absorbent solution is recycled through lines 6 and 9 to zone ZA.

A treatment system to efficiently remove lead from dust contained in extracted cement kiln combustion gas while reducing facility and running costs. A treatment system 1 comprising: a probe 3 for extracting a part of combustion gas, while cooling it, from a kiln exhaust gas passage, which runs from an inlet end of a cement kiln to a bottom cyclone; a classifier 5 for separating coarse powder from dust contained in the combustion gas extracted by the probe 3; a wet dust collector 6 for collecting dust from the extracted gas containing fine powder discharged from the classifier 5; and devices 12, 13 for feeding sulfurizing agent for sulfurizing lead contained in the kiln exhaust gas to the wet dust collector 6, and others. From the sulfurizing-agent feeders 12, 13 are preferably added the sulfurizing agents to a circulation liquid tank 7 or a pump 9 for circulating slurry. The slurry obtained by the wet dust collector 6 is separated into froth including lead and tail side slurry including gypsum by a flotation facility 14, 17, 18.

Controlling the reductive capacity of an aqueous alkaline slurry (23) in a wet scrubber makes it possible to accurately control the mercury emission from the scrubber to a desired value. One method of controlling the reductive capacity of the slurry is to measure the reduction-oxidation potential (“redox potential”) of the aqueous alkaline slurry (23) and to add or remove substances that affect the redox potential and thus the reductive capacity of the slurry. In wet scrubbers in which limestone is used for absorption of acid gases and where a gypsum slurry is circulated, it has been found to be an attractive solution to control the amount of oxidation air blown into the scrubber in order to control the redox potential and thereby the mercury emissions.

The combustion fume flowing in through line 1 is decarbonated by contacting with a solvent in column C2. The solvent laden with carbon dioxide is regenerated in zone R. The purified fume discharged through line 9 comprises part of the solvent. The method allows to extract the solvent contained in the purified fume. The purified fume is contacted in zone ZA with a non-aqueous ionic liquid of general formula Q+ A−; Q+ designates an ammonium, phosphonium and / or sulfonium cation, and A− an anion likely to form a liquid salt. The solvent-depleted purified fume is discharged through line 17. The solvent-laden ionic liquid is regenerated by heating in evaporation device DE. The solvent separated from the ionic liquid in device DE is recycled.

A mercury removing device includes a gasification unit that converts a non-gaseous-mercury-chlorinating agent, which is non-gaseous at room temperature and normal pressure, into gaseous-mercury-chlorinating agent by heating the non-gaseous-mercury-chlorinating agent with heat of hot air generated by using the exhaust gas or hot air generated by using an air heater installed in a flue that conveys the exhaust gas. The gaseous-mercury-chlorinating agent produced in this manner is supplied to the exhaust gas in the flue.