Abstract: Disclosed is a method for treating or using offgases obtained in a melamine plant comprising at least one melamine synthesis reactor and at least one washing unit in an integrated process for urea and melamine production, wherein the offgases leaving the melamine synthesis reactor are fed into the washing section and the washed offgases leaving the washing section are transferred from the washing section via at least one pipeline connecting the washing section and the at least one urea synthesis plant to the at least one urea synthesis plant. The washed offgases leaving the washing section are mixed with at least one carbamate solution immediately downstream of the washing section by feeding the carbamate solution into the pipeline connecting the washing section to the urea plant.

Abstract: The present invention relates to a method for recycling water in a melamine production process comprising—a wet process comprising the steps of aqueous treatment of a melamine melt from a melamine synthesis plant with an aqueous alkali containing solution and crystallization for producing solid melamine and a triazine containing alkaline mother liquor,—a wastewater treatment process comprising the steps of thermal treatment of said triazine containing alkaline motor liquor, and—a recycling process, whereby at least parts of the thermally treated alkaline mother liquor are being recycled to the wet process.

Abstract: A high-pressure melamine reactor is provided. The high-pressure melamine reactor comprising at least one horizontal reactor body having a bottom and a top side with at least one dome integrally formed on the top side of the reactor body. The at least one horizontal reactor body comprises at least two compartments separated by at least one baffle, in particular an overflow baffle. The at least one dome is solely located above at least one of the compartments serving as melamine synthesis unit, wherein the at least one compartment serving as melamine synthesis unit comprises at least one heating element.

Abstract: Disclosed is a method for treating or using offgases obtained in a melamine plant comprising at least one melamine synthesis reactor and at least one washing unit in an integrated process for urea and melamine production, wherein the offgases leaving the melamine synthesis reactor are fed into the washing section and the washed offgases leaving the washing section are transferred from the washing section via at least one pipeline connecting the washing section and the at least one urea synthesis plant to the at least one urea synthesis plant. The washed offgases leaving the washing section are mixed with at least one carbamate solution immediately downstream of the washing section by feeding the carbamate solution into the pipeline connecting the washing section to the urea plant.

Abstract: In a gas scrubber, a gas stream containing at least one sublimed substance is brought in contact with a liquid or melt stream containing at least one thermally convertible substance, which has a lower temperature than the gas stream. For the intensive and intimate mixing of the gas stream with the liquid or melt stream, an orifice plate with a plurality of holes each surrounded by a retaining edge is provided in the upper part of the gas scrubber, and above the orifice plate inlets for the gas stream and the liquid or melt stream are provided.

Abstract: A high-pressure melamine reactor is provided. The high-pressure melamine reactor comprising at least one horizontal reactor body having a bottom and a top side with at least one dome integrally formed on the top side of the reactor body. The at least one horizontal reactor body comprises at least two compartments separated by at least one baffle, in particular an overflow baffle. The at least one dome is solely located above at least one of the compartments serving as melamine synthesis unit, wherein the at least one compartment serving as melamine synthesis unit comprises at least one heating element.

Abstract: The present invention relates to a method for recycling water in a melamine production process comprising—a wet process comprising the steps of aqueous treatment of a melamine melt from a melamine synthesis plant with an aqueous alkali containing solution and crystallization for producing solid melamine and a triazine containing alkaline mother liquor,—a wastewater treatment process comprising the steps of thermal treatment of said triazine containing alkaline motor liquor, and—a recycling process, whereby at least parts of the thermally treated alkaline mother liquor are being recycled to the wet process.

Abstract: The invention concerns a method for producing melamine by dissolving urea, in which solid, liquid or gaseous media other than the gas mixture consisting of the components formed during the reaction is used to desublime the melamine from the gas phase.

Abstract: The invention relates to a method for producing melamine by decomposing urea inside a fluidised bed reactor, during which the hot reaction gas is cooled inside a gas cooler, and the obtained heat is directly used for pre-heating the fluidizing gas required for creating the fluidized bed.

Abstract: In a gas scrubber, a gas stream containing at least one sublimed substance is brought in contact with a liquid or melt stream containing at least one thermally convertible substance, which has a lower temperature than the gas stream. For the intensive and intimate mixing of the gas stream with the liquid or melt stream, an orifice plate with a plurality of holes each surrounded by a retaining edge is provided in the upper part of the gas scrubber, and above the orifice plate inlets for the gas stream and the liquid or melt stream are provided.

Abstract: The invention concerns a method for producing melamine by dissolving urea, in which solid, liquid or gaseous media other than the gas mixture consisting of the components formed during the reaction is used to desublime the melamine from the gas phase.

Abstract: The invention relates to a method for producing melamine by decomposing urea inside a fluidised bed reactor, during which the hot reaction gas is cooled inside a gas cooler, and the obtained heat is directly used for pre-heating the fluidising gas required for creating the fluidised bed.