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.

The present invention relates to an advanced system for the removal of air pollutants from combustion and non-combustion processes that generate air pollutants that are regulated by environmental agencies. The pollutants include, but are not limited to, particulate matter; acid gases including sulphur dioxide, hydrogen chloride and hydrogen fluoride; metals such as mercury, dioxins, VOCs and reagents such as ammonia. The system collects and processes the polluted gas stream through two forms of wet method scrubbing technology. The gas is first passed through a wet scrubbing reactor capable of complete interaction between the gas and the selected liquid scrubbing reagent at one or more interfaces. The scrubbing medium is selected for its reactivity with the pollutants targeted in the process, its cost and impact on the environment. From the exit of the scrubbing reactor the gas is directed through a wet electrostatic precipitator to remove the remaining targeted pollutants to very high removal efficiency.

The present invention concerns a powdery slaked lime composition an Alpine fluidity greater than 50% and including a first fraction of particles having a size less than 32 m and a second fraction of particles with the size greater than 32 m, the second fraction being less than 10% by weight, compared to the total weight of the composition. The invention also relates to a method for producing same.

An apparatus and a method are useful for removing pollutants from process effluent gas produced by an electrolytic cell used in an aluminum production plant to produce aluminum. The apparatus and method use a flow control device to control alumina supply to an electrolytic cell and to a dry scrubber contact reactor.

Disclosed is a process for treating a gas stream containing hydrochloric acid, hydrofluoric acid, a fluorinated compound and halogenated organic compounds, wherein the gas stream is subjected to: (a) a step of washing with an acid solution to obtain a washed gas stream; (b) a step of adiabatic absorption in an aqueous solution of the hydrochloric acid contained in said washed gas stream, to collect a solution of hydrochloric acid; (c) a step of adsorption on activated carbon of the impurities present in said hydrochloric acid solution, to obtain a purified hydrochloric acid solution and a gas stream containing said fluorinated compound; and (d) a step of bringing said purified hydrochloric acid solution into contact with a silica gel. Also disclosed is a plant for the implementation of this process, and also a process for preparing a fluorinated compound comprising the catalytic pyrolysis of an organofluorine compound.

An exhaust gas treatment apparatus which includes a denitration device, a dust collector, and a desulfurization device in order, respectively, in a flow path of exhaust gas discharged from a boiler, wherein a heavy-metal component removal device is provided in the exhaust gas flow path between the dust collector and the desulfurization device. This device is provided with: an absorption tower including a nozzle which sprays acidic absorption liquid on the exhaust gas, a tank which stores liquid which has absorbed a heavy metal, and a pump which supplies the nozzle with the liquid in the tank; a neutralizing tank which neutralizes the liquid drawn from the absorption tower; and a separator which separates the neutralized liquid into a solid and a liquid component. Since a small amount of heavy metal can be removed in the absorption tower, re-emission of the heavy metal by the desulfurization device is prevented.

A manufacturing apparatus according to an embodiment is a manufacturing apparatus of a semiconductor device or a liquid crystal device including a process chamber discharging exhaust gas, a waste liquid discharger discharging waste liquid including a part of the exhaust gas, a first pipe provided between the process chamber and the waste liquid discharger, having a first opening area in a cross section in a direction perpendicular to a moving direction of the exhaust gas, a second pipe provided between the first pipe and the waste liquid discharger, having a second opening area smaller than the first opening area in a cross section in the direction perpendicular to the moving direction of the exhaust gas, and a third pipe connected to the first pipe, the third pipe supplying a condensing agent having a normal boiling point of equal to or higher than 25 C. to the first pipe.

A chemical filter includes a first buffer layer, at least one first filter layer disposed on the first buffer layer and including a pair of first air-permeable bodies facing each other and at least one first adsorption layer between the pair of first air-permeable bodies, and a second filter layer disposed on the first filter layer and including a pair of second air-permeable bodies facing each other and at least one second adsorption layer between the pair of second air-permeable bodies, wherein the first filter layer is configured to be attachable to and detachable from the second filter layer.

An exhaust gas abatement system includes an exhaust gas abatement section configured to abate exhaust gases by utilizing thermal energy and to cool the abated gases by using a liquid, a circulating section configured to circulate the liquid within a circulation path as a circulating liquid, a heat exchange tube configured to cool the circulating liquid and to executes a heat exchange between a cooling liquid which flows in an interior of the heat exchange tube and the circulating liquid which flows outside the heat exchange tube, and a circulating liquid storage portion configured to store the circulating liquid. The heat exchange tube is disposed in a heat exchange tube installation space which is in at least part of an interior of the circulating liquid storage portion.

Disclosed is a purification method for removing a metal component from a fluorine gas containing hydrogen fluoride and a metal component. This method includes a removing step for removing the hydrogen fluoride and the metal component therefrom by bringing the fluorine gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride. The content of the hydrogen fluoride in the fluorine gas before the removing step is 50 volume ppm to 1 volume %, relative to the total volume of the fluorine gas, the hydrogen fluoride and the metal component. The metal fluoride is preferably an alkali metal fluoride or an alkali earth metal fluoride. Surprisingly, the presence of hydrogen fluoride in a fluorine gas makes it possible to remove a metal component therefrom as an impurity as a result of adsorption thereof by a metal fluoride.