Abstract: The present invention relates to a method for contemporaneously recovering ammonia and carbon dioxide from an aqueous solution thereof, possibly comprising their condensates, in a synthesis process of urea, characterized in that it comprises a hydrophobic microporous membrane distillation phase of an aqueous solution comprising ammonia, carbon dioxide and their saline compounds or condensates, said distillation being carried out at a temperature ranging from 50 to 250° C. and a pressure ranging from 50 KPa to 20 MPa absolute, with the formation of a residual aqueous solution, possibly comprising urea, and a gaseous permeate stream, comprising ammonia, carbon dioxide and water. The present invention also relates to an apparatus for effecting the above method and a production process of urea which comprises the above method.

Abstract: The present invention relates to a method for contemporaneously recovering ammonia and carbon dioxide from an aqueous solution thereof, possibly comprising their condensates, in a synthesis process of urea, characterized in that it comprises a hydrophobic microporous membrane distillation phase of an aqueous solution comprising ammonia, carbon dioxide and their saline compounds or condensates, said distillation being carried out at a temperature ranging from 50 to 250° C. and a pressure ranging from 50 KPa to 20 MPa absolute, with the formation of a residual aqueous solution, possibly comprising urea, and a gaseous permeate stream, comprising ammonia, carbon dioxide and water. The present invention also relates to an apparatus for effecting the above method and a production process of urea which comprises the above method.

Abstract: The present invention relates to a method for contemporaneously recovering ammonia and carbon dioxide from an aqueous solution thereof, possibly comprising their condensates, in a synthesis process of urea, characterized in that it comprises a hydrophobic microporous membrane distillation phase of an aqueous solution comprising ammonia, carbon dioxide and their saline compounds or condensates, said distillation being carried out at a temperature ranging from 50 to 250° C. and a pressure ranging from 50 KPa to 20 MPa absolute, with the formation of a residual aqueous solution, possibly comprising urea, and a gaseous permeate stream, comprising ammonia, carbon dioxide and water. The present invention also relates to an apparatus for effecting the above method and a production process of urea which comprises the above method.

Abstract: The present invention relates to a process for the recovery of ammonia contained in a gaseous stream, said process comprising the following phases: (a) subjecting the gaseous stream containing ammonia to a washing with an aqueous washing solution having a pH lower than 7.0, with the formation of a purified gaseous stream and an aqueous solution containing an ammonium salt; (b) treating the aqueous solution containing the ammonium salt coming from phase (a) in a vertical falling film heat exchanger at a temperature from 50 to 250° C. and an absolute pressure ranging from 50 KPa to 4 MPa with the formation of a regenerated washing solution and a gaseous stream comprising NH3 and H2O; (c) recycling said regenerated washing solution to phase (a). The present invention also relates to equipment for effecting the above process.

Abstract: A process for the recovery of ammonia contained in a gaseous stream is described, said process comprising the following phases: (a) subjecting the gaseous stream containing ammonia to a washing (S) with an aqueous washing solution (5a) having a pH lower than 7.0, with the formation of a purified gaseous stream (6) and an aqueous solution (7) containing an ammonium salt; (b) subjecting the aqueous solution containing the ammonium salt coming from phase (a) to a distillation process (MD) with a hydrophobic microporous membrane at a temperature ranging from 50 to 250° C. and a pressure ranging from 50 KPa to 4 MPa absolute with the formation of a regenerated washing solution (16) and a gaseous stream (18) comprising NH3 and H2O; (c) recycling said generated washing solution to phase (a). The equipment for carrying out the above process is also described.

Abstract: A process for the recovery of ammonia contained in a gaseous purging stream produced in a synthesis process of urea.

Abstract: The present invention relates to a method for contemporaneously recovering ammonia and carbon dioxide from an aqueous solution thereof, possibly comprising their condensates, in a synthesis process of urea, characterized in that it comprises a hydrophobic microporous membrane distillation phase of an aqueous solution comprising ammonia, carbon dioxide and their saline compounds or condensates, said distillation being carried out at a temperature ranging from 50 to 250° C. and a pressure ranging from 50 KPa to 20 MPa absolute, with the formation of a residual aqueous solution, possibly comprising urea, and a gaseous permeate stream, comprising ammonia, carbon dioxide and water. The present invention also relates to an apparatus for effecting the above method and a production process of urea which comprises the above method.

Abstract: The present invention relates to a process for the recovery of ammonia contained in a gaseous stream, said process comprising the following phases: (a) subjecting the gaseous stream containing ammonia to a washing with an aqueous washing solution having a pH lower than 7.0, with the formation of a purified gaseous stream and an aqueous solution containing an ammonium salt; (b) treating the aqueous solution containing the ammonium salt coming from phase (a) in a vertical falling film heat exchanger at a temperature from 50 to 250° C. and an absolute pressure ranging from 50 KPa to 4 MPa with the formation of a regenerated washing solution and a gaseous stream comprising NH3 and H2O; (c) recycling said regenerated washing solution to phase (a). The present invention also relates to equipment for effecting the above process.

Abstract: A process for the recovery of ammonia contained in a gaseous stream is described, said process comprising the following phases: (a) subjecting the gaseous stream containing ammonia to a washing (S) with an aqueous washing solution (5a) having a pH lower than 7.0, with the formation of a purified gaseous stream (6) and an aqueous solution (7) containing an ammonium salt; (b) subjecting the aqueous solution containing the ammonium salt coming from phase (a) to a distillation process (MD) with a hydrophobic microporous membrane at a temperature ranging from 50 to 250° C. and a pressure ranging from 50 KPa to 4 MPa absolute with the formation of a regenerated washing solution (16) and a gaseous stream (18) comprising NH3 and H2O; (c) recycling said generated washing solution to phase (a). The equipment for carrying out the above process is also described.

Abstract: The present invention relates to a process for the recovery of ammonia contained in a gaseous purging stream produced in a synthesis process of urea, comprising the following phases: a) subjecting the gaseous purging stream to a washing with an aqueous acidic solution, at a pH ranging from 1 to 6, with the formation of a first purified gaseous stream and an aqueous solution containing an ammonium salt; b) subjecting the aqueous solution containing the ammonium salt coming from phase a) to stripping, after treatment with a strong base, at a temperature ranging from 50 to 250° C.