摘要:
A process for desulfurizing an exhaust gas which comprises desulfurizing an exhaust gas containing SO.sub.2 by bringing it into contact with a slurry containing calcium compounds and aluminum compounds, characterized in that the concentration of the dissolved aluminum ion in said slurry is detected and a manganese compound is supplied into said slurry in such a manner that the ratio of the concentration of manganese (including both solid and liquid) to said concentration of the dissolved aluminum ion may be maintained in a molar ratio of less than 1 in said slurry.
摘要:
An exhaust fume desulfurization process is disclosed which comprises the steps of contacting an off-gas containing SO.sub.2 with a slurry containing calcium and manganese compounds, introducing a gas containing oxygen into the slurry, detecting the amount of the absorption of oxygen by the slurry, and regulating the amount of manganese present in the slurry based upon the amount of oxygen absorbed by the slurry. The desulfurization rate is correspondingly adjusted and the desulfurized gas product is recovered.
摘要:
The present invention is directed to a method for treating a waste gas to separate and recover gypsum and a dust therein, characterized by comprising the steps of causing the waste gas to pass through a dry dust collector; introducing the gas into a gas absorber, in which a slurry containing at least one of calcium hydroxide or calcium carbonate as an absorbent is employed to remove SO.sub.2 and the dust passed through the dry dust collector from the waste gas; blowing air into the resultant absorbing liquid in the gas absorber to oxidize the absorbing liquid and to thereby produce gypsum; delivering them to an absorbing liquid tank, in which the slurry mainly containing the gypsum grains is separated from the other slurry mainly containing the dust by partition walls disposed therein; and directly taking out the respective slurries separately from the absorbing liquid tank.
摘要:
A method for controlling the concentration of a slurry in an absorption tower in which a flue gas comprising SO.sub.2 is brought into contact with a slurry containing suspended Ca compounds therein to absorb the SO.sub.2 with the compounds. The method comprises withdrawing the slurry from the absorption tower in such a way that the slurry is divided into at least two groups with different concentrations, one group being a slurry having a higher concentration of the Ca compound, the other group being a slurry having a lower concentration of the Ca compound, and regulating rates of the slurries being withdrawn from the absorption tower whereby the concentration of the Ca compound in the slurry being contacted with the flue gas is controlled.
摘要:
A method for the wet treatment of combustion exhaust gases comprising SO.sub.2 and HCl, the method comprising detecting an amount of HCl in the exhaust gas and feeding, to an exhaust gas treating tower, a sodium salt in an amount corresponding to at least the detected amount of HCl so that all the HCl is able to be converted into NaCl in the exhaust gas treating tower, along with CaCO.sub.3 or Ca(OH).sub.2 used as an SO.sub.2 absorbent.
摘要:
Here are disclosed a method for desulfurizing an exhaust gas which is characterized by comprising a gas absorbing section in which an absorbing solution absorbs SO.sub.2 in the exhaust gas in order to become an acid solution containing a sulfite; an oxidizing section in which the sulfite is oxidized; a neutralizing section in which the absorbing solution is neutralized by adding an SO.sub.2 absorbent; and a closed circulating circuit for delivering the solution drawn out from the gas absorbing section to the oxidizing section, delivering the solution drawn out from the oxidizing section to the neutralizing section, and delivering the solution drawn out from the neutralizing section to the gas absorbing section; and a method for simultaneously treating SO.sub.2 and HCl which the abovementioned exhaust gas contains.
摘要:
Here is disclosed a method for treating SO.sub.2, SO.sub.3 and a dust simultaneously which comprises causing an exhaust gas containing at least SO.sub.2, SO.sub.3 and the dust to pass through a dry dust collector in order to remove most of the dust therefrom, delivering the exhaust gas to a gas absorbing device, and using at least one of calcium hydroxide and calcium carbonate as an absorbent in the gas absorbing device to remove SO.sub.2 and the dust, which has passed through the dry dust collector, in the exhaust gas therefrom, the method being characterized by comprising the steps of blowing air into an absorbing solution fed to the gas absorbing device in order to oxidize the absorbing solution and to thereby form a gypsum therein; separating a part of the absorbing solution into a slurry mainly containing the gypsum grains and a slurry mainly containing the dust; obtaining the by-product gypsum from the slurry mainly containing the gypsum grains; adding an alkali to the slurry mainly containing the dust; spraying this slurry into the exhaust gas on the upstream side of the dry dust collector; carrying out the collection, drying and solidification of SO.sub.3 ; and collecting the resultant solid together with the dust by the dry dust collector.
摘要:
In treating exhaust gases containing SO.sub.2, HCl and HF, there is disclosed a method of treating such exhaust gas which comprises detecting the amounts of HCl and HF in the exhaust gas and supplying an amount of a magnesium compound commensurate with a stoichiometric amount to become at least MgCl.sub.2 and MgF.sub.2 in an exhaust-gas treating tower and a calcium compound as a SO.sub.2 solvent into the exhaust-gas treating tower.The aforesaid method of treating an exhaust gas comprises a method of causing Mn ion to coexist in an absorbing solution in contact with the exhaust gas.
摘要:
Nitrogen oxides and sulfur oxides are removed from exhaust gases in a two step process including a slurry removal of the sulfur oxides followed by washing the gases with an aqueous solution of an alkali metal iodide and/or an alkaline earth metal iodide.
摘要:
A process for wet-treating an exhaust gas to remove oxides of sulfur and of nitrogen including:1. washing the exhaust gas with a slurry containing one or more magnesium compounds to remove oxides of sulfur from the exhaust gas;2. washing the exhaust gas treated in step (1) with an aqueous solution of an alkali metal iodide and/or an alkaline earth metal iodide to remove the oxide of nitrogen; and3. contacting the slurry from step (1) with the aqueous solution from step (2) to regenerate the solution of alkali metal iodide and/or alkaline earth metal iodide and to decompose any nitrite formed in step (2) to nitrogen.