A dehydration method in accordance with an embodiment of the present invention includes: a first dehydration step of bringing hydrogen chloride gas (21) and concentrated sulfuric acid (13A) into contact with each other; and a second dehydration step of bringing hydrogen chloride gas (21A) that has been obtained through the first dehydration step into contact with concentrated sulfuric acid (13B). A concentration of the concentrated sulfuric acid used in the second dehydration step is higher than a concentration of the concentrated sulfuric acid used in the first dehydration step.

A method for producing aqueous hydrochloric acid from flue gases is provided. The method comprises conveying water to a first scrubber (102, 202, 302, 402, 502, 602, 702) or to a line (112b, 212b, 312b, 412b, 512b, 712b, 712c) to use the water in a scrubbing liquid of the first scrubber. The method also comprises providing flue gas containing chlorides into the first scrubber (102, 202, 302, 402, 502, 602, 702) and scrubbing the flue gas containing chlorides with the scrubbing liquid by contacting the flue gas with the scrubbing liquid in the first scrubber (102, 202, 302, 402, 502, 602, 702). Dilute hydrochloric acid and a flue gas derivate (104, 204, 304, 404, 504, 704) are produced. The method comprises letting out at least some of the dilute hydrochloric acid from the first scrubber (102, 202, 302, 402, 502, 602, 702) as a scrubber bleed, separating solids suspended by the scrubber bleed in a solids separator (192, 592, 692), conveying the scrubber bleed from the solids separator (192, 592, 692) into an evaporation vessel (194, 594, 694) and concentrating the scrubber bleed in the evaporation vessel (194, 594, 694) to produce hydrochloric acid vapor having a concentration of 5-22 wt-%. A corresponding system is also provided.

A method for producing a hydrogen chloride. A pressurized highly concentrated hydrochloric acid having a hydrogen chloride concentration of 35% by weight or above is fed into a high pressure desorption device, the high pressure desorption device is operated at a pressure P.sub.des of 2 bar or above and at a temperature T from 110 to 200° C. in the bottom of the high pressure desorption device, and the hydrogen chloride is desorbed in the high pressure desorption device.

A method for producing aqueous hydrochloric acid from flue gases is provided. The method comprises conveying water to a first scrubber (102, 202, 302, 402, 502, 602, 702) or to a line (112b, 212b, 312b, 412b, 512b, 712b, 712c) to use the water in a scrubbing liquid of the first scrubber. The method also comprises providing flue gas containing chlorides into the first scrubber (102, 202, 302, 402, 502, 602, 702) and scrubbing the flue gas containing chlorides with the scrubbing liquid by contacting the flue gas with the scrubbing liquid in the first scrubber (102, 202, 302, 402, 502, 602, 702). Dilute hydrochloric acid and a flue gas derivate (104, 204, 304, 404, 504, 704) are produced. The method comprises letting out at least some of the dilute hydrochloric acid from the first scrubber (102, 202, 302, 402, 502, 602, 702) as a scrubber bleed, separating solids suspended by the scrubber bleed in a solids separator (192, 592, 692), conveying the scrubber bleed from the solids separator (192, 592, 692) into an evaporation vessel (194, 594, 694) and concentrating the scrubber bleed in the evaporation vessel (194, 594, 694) to produce hydrochloric acid vapor having a concentration of 5-22 wt-%. A corresponding system is also provided.

A hydrogen chloride loop fuel reaction is designed and configured for turbine/generator combination which can be used for automotive propulsion or as a standalone electrical generation or for auxiliary equipment. A method for providing a hydrogen chloride loop fuel reaction includes creating hydrogen chloride fuel in a sealed furnace vessel, wherein at start up, the sealed furnace vessel is vacuumed out and hydrogen and chlorine are injected into a burner and ignited resulting in the hydrogen chloride fuel in an exhaust stream of the sealed furnace vessel; and looping the hydrogen chloride fuel leaving the sealed furnace vessel in the exhaust stream of the sealed furnace vessel.

The invention relates to a method for flexibly controlling the use of hydrochloric acid having an HCl concentration of at least 10 wt %, in particular at a volume flow rate of at least 1 m.sup.3/h, obtained from a continuous chemical production process (A). In the method, purified hydrochloric acid (54) from a hydrochloric acid store (E) is optionally fed to a dispatch station (H), an HCl electrolysis station (F) and a chloralkali electrolysis station (L), which are consumption points for the hydrochloric acid, or to a neutralisation station (G) in that if one or more of said consumption points (H, F, L) is not available or if there are bottlenecks at the consumption points (H, F, L), the hydrochloric acid (54) is fed to the neutralisation station (G) and neutralised with concentrated alkali solution (55), in particular with concentrated sodium hydroxide solution, and the resulting salt solution (56) is fed either to the chloralkali process station (L) or to a disposal station (M).

Disclosed is a method and a device for the continuous neutralization of hydrochloric acid at an industrial scale.

A method for producing a hydrogen chloride mixture containing hydrogen chloride and water, the method including: a first dehydration step of cooling a hydrogen chloride mixture in which a concentration of water is 1 mol ppm or more, to condense and separate water in the hydrogen chloride mixture; a second dehydration step of bringing a hydrogen chloride mixture obtained in the first dehydration step into contact with a water adsorbent to allow a concentration of water to be less than 0.5 mol ppm; and a filling step of filling a filling container with a hydrogen chloride mixture obtained in the second dehydration step so that at least a part of the hydrogen chloride mixture is liquid, and a concentration of water in a liquid phase at a time of completion of the filling is 0.01 mol ppm or more and less than 1 mol ppm.

The invention pertains to a method for recovering HCl from a HCl containing gas stream wherein a HCl containing gas stream with a temperature of 20 to 25 C. is provided to an adiabatic absorption unit where it is contacted with water as an absorbent, resulting in the formation of a top gas stream and a aqueous HCl product solution, wherein the temperature of the top gas stream is at least 70 C. and wherein the aqueous HCl product solution has a HCl concentration in the range of 5-20 wt. %. It is preferred for the HCl-containing gas stream to be derived from a hydrogenation step wherein a feed comprising monochloroacetic acid (MCA) and dichloroacetic acid (DCA) is reacted with hydrogen to form a HCl-containing gas stream and a product stream comprising MCA and a reduced amount of DCA. The HCl product solution is preferably diluted to a concentration of 1-8 wt. %, and the diluted solution is used as absorbent in a second absorption step, wherein HCl is absorbed from a further HCl-containing gas stream to form a second aqueous HCl solution. The further HCl-containing gas stream is preferably derived from a chlorination step wherein acetic acid is reacted with chlorine, resulting in the formation of the further HCl-containing gas stream and a feed comprising monochloroacetic acid (MCA) and dichloroacetic acid (DCA).

A hydrogen gas recovery system according to the present ingestion is configured by a condensation and separation apparatus (A) that condenses and separates chlorosilanes from a hydrogen-containing reaction exhaust gas exhausted from a polycrystalline silicon production step, a compression apparatus (B) that compresses the hydrogen-containing reaction exhaust gas, an absorption apparatus (C) that absorbs and separates hydrogen chloride by contacting the hydrogen-containing reaction exhaust gas with an absorption liquid, a first adsorption apparatus (D) comprising an adsorption column filled with activated carbon for adsorbing and removing methane, hydrogen chloride, and part of the chlorosilanes each contained in the hydrogen-containing reaction exhaust gas, a second adsorption apparatus (E) comprising an adsorption column filled with synthetic zeolite that adsorbs and removes methane contained in the hydrogen-containing reaction exhaust gas, and a gas line (F) that recovers a purified hydrogen gas having a reduced concentration of methane.