A method for preparing Cl—SO.sub.2NHSO.sub.2Cl including a step of chlorinating sulphamic acid with at least one chlorinating agent and at least one sulphur-containing agent, the method resulting in a flow F1, preferably liquid, including Cl—SO.sub.2NHSO.sub.2Cl and a gas stream F2 including HCl and SO.sub.2, the method including a step a) of treating the gas stream F2. Also, a method for preparing LiFSI including the abovementioned method for preparing Cl—SO.sub.2NHSO.sub.2Cl.

A device for waste gas scrubbing in a urea plant may be configured such that a waste gas passes along a transportation direction in the duct. The duct may include a first region for removing urea dust particles from the waste gas and a second region for removing chemical compounds from the waste gas, which can be integrated by an acid-base reaction into an aqueous liquid phase. A cross-sectional area of the duct extending perpendicular to the transportation direction in the second region may be greater than a cross-sectional area extending perpendicular to the transportation direction in the first region. Further, the device may be configured such that the duct extends horizontally at least in sections and/or the transportation direction of the waste gas through the duct extends horizontally in an installed state.

An improvement in a wet scrubbing process for treating gaseous industrial process streams which contain one or more of SO.sub.2, SO.sub.3, H.sub.2SO.sub.4 which comprises contacting the stream of gas with a countercurrent flow of liquid derived from a circulating liquid stream which includes (i) a purge stream configured to remove a portion of the circulating liquid having a concentration of H.sub.2SO.sub.4 from the process, and (ii) a liquid make-up stream configured to replace the portion of the circulating liquid that is removed from the circulating liquid stream, the improvement comprising controlling the flow of liquid make-up whereby the concentration of H.sub.2SO.sub.4 in the purge stream is increased to a useful value; and filtering the purge stream to remove unwanted contaminants to yield a clarified purge stream.

Disclosed is an apparatus for separating amine gas from mixed gas, the apparatus including: a washer column through which mixed the gas passes; and a main adsorber column through which the mixed gas passing through the washer column passes. According to the present invention, the apparatus can remove amine gas more effectively and increase the lifetime of an adsorbent by allowing the mixed gas including the amine gas to pass through the washer column and the adsorber column.

A method of desulfurizing a liquid hydrocarbon comprises providing an initial processing unit and an end processing unit, the initial processing unit having an initial reactor assembly and an initial sorption system, the end processing unit having an end reactor assembly, a separator and an end sorption system. The method further comprises feeding a liquid hydrocarbon having a sulfur content into the initial reactor assembly, feeding an aqueous feed into the initial reactor assembly, shear mixing the liquid hydrocarbon and the aqueous feed within the initial reactor assembly, to, in turn, react the aqueous feed with the sulfur content of the liquid hydrocarbon, and directing the liquid hydrocarbon and aqueous feed to the initial sorption system. The method even further comprises feeding a sorbent into the initial sorption system and adsorbing at least some of the sulfur content that has reacted with the aqueous feed from the liquid hydrocarbon.

A process for purifying exhaust air from a granulation plant for producing a urea-containing granulate includes contacting a gas stream containing a urea-containing dust and ammonia with a sulfuric acid solution or a nitric acid solution in a scrubbing process. The scrubbing process involves scrubbing the gas stream with a first weakly acidic scrubbing solution in a first scrubbing stage and scrubbing the gas stream exiting the first scrubbing stage with a second scrubbing solution having a lower pH than the first weakly acidic scrubbing solution in a second scrubbing stage. The acidic scrubbing solution generated in the second scrubbing stage may be recycled into the first scrubbing stage via a conduit and used therein as the first weakly acidic scrubbing solution. A pre-scrubbing stage for scrubbing dust out of the gas stream may additionally be arranged upstream of the first scrubbing stage.

Disclosed are methods and systems for removing submicron particles from a gas stream, in particular from urea prilling off-gas, wherein a Venturi ejector is used. A method comprises contacting a gas stream containing submicron particles in a Venturi ejector with an injected high velocity scrubbing liquid to provide a pumping action, wherein the scrubbing liquid has an initial velocity of at least 25 m/s and wherein the ratio of scrubbing liquid and gas flow is between 0.0005 and 0.0015 (m.sup.3/h)/(m.sup.3/h).

Disclosed are methods and systems for removing submicron particles from a gas stream, in particular from urea prilling off-gas, wherein a Venturi ejector is used. A method comprises contacting a gas stream containing submicron particles in a Venturi ejector with an injected high velocity scrubbing liquid to provide a pumping action, wherein the scrubbing liquid has an initial velocity of at least 25 m/s and wherein the ratio of scrubbing liquid and gas flow is between 0.0005 and 0.0015 (m.sup.3/h)/(m.sup.3/h).

The invention relates to a method for recovery of urea dust and ammonia from a gas stream by contacting said gas stream with an aqueous sulphuric acid solution, thus forming an acid solution of ammonium sulphate and urea, characterized in that the acid solution is concentrated to a melt comprising less than 5 wt % of water, which melt is subsequently transferred into solid particles comprising urea and ammonium sulphate.

Systems and methods are provided for reclaiming CO.sub.2 from air. The method includes absorbing solar radiation using a special photovoltaic panel, the H-SPV, which is so designed that the heat absorbed by the H-SPV is conducted to the back of the H-SPV to the substrate, and there it is cooled by the airstream behind it. A second supporting panel is included to provide enclosure for the heated air that rises between the two panels by the chimney effect, the heated air between the at least two plates will rise by the chimney effect, sucking in more air to be heated, wherein the air includes CO.sub.2, chemically removing the CO.sub.2 from the heated air, using a coolant liquid, wherein the coolant liquid in a heat exchanger, when in contact with the CO.sub.2 in the heated air, forms a bicarbonate, and releasing air that has had the CO.sub.2 chemically removed.