A fluidized bed granulator for granulation with urea or urea-containing liquids is described, wherein the granulation liquid is supplied via a supply manifold comprising a header and risers. The risers are at least in part provided inside channels for secondary gas.

Disclosed is a method for the removal of urea dust from the off-gas of a finishing section of a urea production plant. the method comprises subjecting the off-gas to quenching with water so as to produce quenched off-gas, and subjecting the quenched off-gas to scrubbing using at least one venturi scrubber. As a result, a lower pressure drop over the scrubber is attained, and a more efficient growth of urea particles, facilitating the removal thereof.

Disclosed is a method for the removal of urea dust from the off-gas of a finishing section of a urea production plant. the method comprises subjecting the off-gas to quenching with water so as to produce quenched off-gas, and subjecting the quenched off-gas to scrubbing using at least one venturi scrubber. As a result, a lower pressure drop over the scrubber is attained, and a more efficient growth of urea particles, facilitating the removal thereof.

The invention pertains to a finishing process for urea-comprising material, a plant for finishing urea-comprising material, a method of modifying an existing plant, and a use. Methods are disclosed for preventing the clogging of the conduit for off-gas between the finishing section and the treatment section.

The invention pertains to a finishing process for urea-comprising material, a plant for finishing urea-comprising material, a method of modifying an existing plant, and a use. Methods are disclosed for preventing the clogging of the conduit for off-gas between the finishing section and the treatment section.

A process for the production of formaldehyde-stabilised urea is described comprising the steps of: (a) generating a synthesis gas; (b) subjecting the synthesis gas to one or more stages of water-gas shift in one or more water-gas shift reactors to form a shifted gas; (c) cooling the shifted gas to below the dew point and recovering condensate to form a dried shifted gas; (d) recovering carbon dioxide from the dried shifted gas in a carbon dioxide removal unit to form a carbon dioxide-depleted synthesis gas; (e) synthesising methanol from the carbon dioxide-depleted synthesis gas in a methanol synthesis unit and recovering the methanol and a methanol synthesis off-gas; (f) subjecting at least a portion of the recovered methanol to oxidation with air to form formaldehyde in a stabiliser production unit; (g) subjecting the methanol synthesis off-gas to methanation in a methanation reactor containing a methanation catalyst to form an ammonia synthesis gas; (h) synthesising ammonia from the ammonia synthesis gas in an ammonia production unit and recovering the ammonia; (i) reacting a portion of the ammonia and at least a portion of the recovered carbon dioxide stream in a urea production unit to form a urea stream; and (j) stabilising the urea by mixing the urea stream and a stabiliser prepared using the formaldehyde produced in the stabiliser production unit, wherein the carbon dioxide removal unit operates by means of absorption using a liquid absorbent and comprises an absorbent regeneration unit, wherein the process includes recovering a carbon dioxide-containing gas stream from the absorbent regeneration unit, compressing at least a portion of the recovered carbon dioxide-containing gas stream to form a compressed carbon dioxide-containing gas stream and passing the compressed carbon dioxide-containing gas stream to the methanol synthesis unit.

Disclosed are: a treatment method comprising (1) a step in which an aqueous solution containing urea, ammonia and carbon dioxide is introduced into a first stripper (PCS1) and subjected to stripping, and the aqueous solution after stripping is introduced into a urea hydrolyzer (UHY), (2) a step in which urea in the aqueous solution is hydrolyzed in the urea hydrolyzer (UHY), and the aqueous solution after hydrolysis is introduced into a second stripper (PCS2), (3) a step in which the aqueous solution is subjected to stripping in the second stripper (PCS2), and (4) a step in which a part of the aqueous solution before being stripped in the first stripper (PCS1), and/or, a part of the aqueous solution after being stripped in the first stripper (PCS1) but before being hydrolyzed in the urea hydrolyzer (UHY) is introduced into an exhaust gas treatment equipment equipped with an ammonia scrubbing equipment (ASCR); and a treatment equipment therefor.

Disclosed are: a treatment method comprising (1) a step in which an aqueous solution containing urea, ammonia and carbon dioxide is introduced into a first stripper (PCS1) and subjected to stripping, and the aqueous solution after stripping is introduced into a urea hydrolyzer (UHY), (2) a step in which urea in the aqueous solution is hydrolyzed in the urea hydrolyzer (UHY), and the aqueous solution after hydrolysis is introduced into a second stripper (PCS2), (3) a step in which the aqueous solution is subjected to stripping in the second stripper (PCS2), and (4) a step in which a part of the aqueous solution before being stripped in the first stripper (PCS1), and/or, a part of the aqueous solution after being stripped in the first stripper (PCS1) but before being hydrolyzed in the urea hydrolyzer (UHY) is introduced into an exhaust gas treatment equipment equipped with an ammonia scrubbing equipment (ASCR); and a treatment equipment therefor.

A process for reducing nitrogen oxides in an exhaust stream, such as a vehicle exhaust stream, and apparatus for carrying out the process. The process comprises providing a first composition comprising aqueous urea, a second composition comprising ammonium carbamate and an exhaust stream comprising nitrogen oxides. A process for producing the ammonium carbamate is also provided. The second composition may be introduced into the exhaust stream (10) when the exhaust stream has a temperature below a threshold temperature and the first composition may be introduced into the exhaust stream when the exhaust stream has a temperature at or above the threshold temperature.

Compositions and methods are presented that selectively dissolve calcium from a variety of cementitious materials without dissolving or otherwise degrading calcium silica hydrate (CSH). Preferably, contemplated compositions comprise guanidine bisulfate hydrochloride, which can be prepared from a reaction of urea, hydrochloric acid, and sulfamic acid. Therefore, it is especially contemplated that the compositions contemplated herein are particularly suitable to clean or otherwise condition surfaces of cured concrete, Portland cement-based material, or an aggregate containing CSH.