The present disclosure provides a method for converting the target gas contained in the exhaust gas in plasma phase and an apparatus for implementing the method, the method comprising the steps of: generating a plasma in a conversion region in which the conversion of the target gas occurs; supplying, to the conversion region, a conversion promoting agent containing a conversion promoting element of which the first ionization energy is not greater than 10 eV for promoting the conversion of the target gas; supplying, to the conversion region, a conversion agent that produces conversion products by combining with the dissociation products of the target gas and prevents the dissociation products from recombining into the target gas; and supplying the exhaust gas containing the target gas to the conversion region.

A detoxifying device 100 having an inner wall 104 that forms a flow passage 103 through which treatment gas flows includes a first piping 130 that forms a part of the flow passage 103, a replaceable piping section 170 that forms a part of the flow passage 103 at the position downstream of the first piping 130, and is connected thereto for sprinkling the cleaning water to remove the solid product adhering to the inner wall 104, and a second piping 150 that forms a part of the flow passage 103 at the position downstream of the piping section 170, and is connected thereto.

A contaminated gas stream can be passed through an in-line mixing device, positioned in a duct containing the contaminated gas stream, to form a turbulent contaminated gas stream. One or more of the following is true: (a) a width of the in-line mixing device is no more than about 75% of a width of the duct at the position of the in-line mixing device; (b) a height of the in-line mixing device is no more than about 75% of a height of the duct at the position of the in-line mixing device; and (c) a cross-sectional area of the mixing device normal to a direction of gas flow is no more than about 75% of a cross-sectional area of the duct at the position of the in-line mixing device. An additive can be introduced into the contaminated gas stream to cause the removal of the contaminant by a particulate control device.

An injection lance assembly for creating a higher degree of turbulence and dispersion of a treating agent into a fluid stream.

A unit for recovering hydrogen chloride from an aqueous liquid which includes hydrogen chloride and is contaminated with compounds of low or no volatility, the unit having an evaporation unit for forming, from the liquid, a vapour which contains hydrogen chloride and a liquid concentrate which is contaminated with the compounds of low or no volatility, a first distillation unit for separating the hydrogen-chloride-containing vapour into a first top product and a first bottom product, and a second distillation unit for separating a hydrogen-chloride-containing aqueous fluid into a second top product and a second bottom product, one of these two distillation units being configured to be able to implement therein a distillation above the ambient pressure, and the other of these two distillation units being configured to be able to implement therein a distillation below the ambient pressure.

A unit for recovering hydrogen chloride from an aqueous liquid which includes hydrogen chloride and is contaminated with compounds of low or no volatility, the unit having an evaporation unit for forming, from the liquid, a vapour which contains hydrogen chloride and a liquid concentrate which is contaminated with the compounds of low or no volatility, a first distillation unit for separating the hydrogen-chloride-containing vapour into a first top product and a first bottom product, and a second distillation unit for separating a hydrogen-chloride-containing aqueous fluid into a second top product and a second bottom product, one of these two distillation units being configured to be able to implement therein a distillation above the ambient pressure, and the other of these two distillation units being configured to be able to implement therein a distillation below the ambient pressure.

Calcium hydroxide-containing compositions can be manufactured by slaking quicklime, and subsequently drying and milling the slaked product. The resulting calcium hydroxide-containing composition can have a size, steepness, pore volume, and/or other features that render the compositions suitable for treatment of exhaust gases and/or removal of contaminants. In some embodiments, the calcium hydroxide-containing compositions can include a D.sub.10 from about 0.5 microns to about 4 microns, a D.sub.90 less than about 30 microns, and a ratio of D.sub.90 to D.sub.10 less than 20, wherein individual particles include a surface area greater than or equal to about 25 m.sup.2/g.

Provided is an exhaust gas treatment apparatus that treats exhaust gas generated from semiconductor process and directed to a vacuum pump. Exhaust gas treatment apparatus includes a plasma generating unit for generating plasma, a reaction chamber in which perfluoride is decomposed by the plasma to generate a decomposition gas, and gas supplying unit for supplying the decomposition gas from the reaction chamber to a processing chamber in which the exhaust gas from the semiconductor process is introduced and treated exhaust gas is discharged to the vacuum pump. Decomposition gas reacts with the exhaust gas in the processing chamber to suppress generation of salt in solid state by a component of the exhaust gas.

Provided is an exhaust gas treatment apparatus that treats exhaust gas generated from semiconductor process and directed to a vacuum pump. Exhaust gas treatment apparatus includes a plasma generating unit for generating plasma, a reaction chamber in which perfluoride is decomposed by the plasma to generate a decomposition gas, and gas supplying unit for supplying the decomposition gas from the reaction chamber to a processing chamber in which the exhaust gas from the semiconductor process is introduced and treated exhaust gas is discharged to the vacuum pump. Decomposition gas reacts with the exhaust gas in the processing chamber to suppress generation of salt in solid state by a component of the exhaust gas.

A gas treatment system includes a first scrubber, a regenerative catalytic oxidizer (RCO) that treats gas that passes through the first scrubber, a second scrubber that treats the gas that passed through the regenerative catalytic oxidizer, and a dielectric barrier discharge (DBD) plasma reactor that treats the gas that passed through the second scrubber. The regenerative catalytic oxidizer includes a two-bed regenerative catalytic reactor.