Abstract: An apparatus for treating highly corrosive agents comprises a tube bundle (14) heat exchanger (10), structured to carry out a heat exchange between two fluids one of which is highly corrosive and flowing inside of said tube bundle (14).

Abstract: A process for urea production from ammonia and carbon dioxide, made to react at a predetermined high pressure in an appropriate synthesis reactor (112), from the reaction between NH3 and CO2 being obtained a reaction mixture comprising urea, ammonium carbamate and free ammonia in aqueous solution, from which a recovery of ammonium carbamate and ammonia is carried out with their subsequent recycle to the synthesis reactor (112), said recovery from the reaction mixture taking place through operative steps of decomposition of the ammonium carbamate into NH3 and CO2 and of their stripping and a subsequent operative step of their recondensation into ammonium carbamate that is recycled to the synthesis reactor, the said reaction mixture obtained from the reaction between ammonia and carbon dioxide being pumped to the operative steps of decomposition and stripping.

Abstract: A process for urea production comprises a first process step in which ammonia (7) and carbon dioxide (6) are obtained, subjecting natural gas (1) to reforming treatments (12, 14), and a second step of urea (8a) production from such ammonia (7) and from carbon dioxide, through a formation of a solution comprising urea and ammonium carbamate in a urea synthesis reactor (20) and a subsequent decomposition of the ammonium carbamate and. urea recovery, the process comprises the steps of:—treating combustion smokes (5) comprising carbon dioxide with an aqueous solution (9a) comprising a part (7b) of such ammonia (7), obtaining an aqueous ammonium carbamate solution (9c);—supplying the solution (9c) thus obtained to the second process step.

Abstract: A process for urea production from ammonia and carbon dioxide, made to react at a predetermined high pressure in an appropriate synthesis reactor (112), from the reaction between NH3 and CO2 being obtained a reaction mixture comprising urea, ammonium carbamate and free ammonia in aqueous solution, from which a recovery of ammonium carbamate and ammonia is carried out with their subsequent recycle to the synthesis reactor (112), said recovery from the reaction mixture taking place through operative steps of decomposition of the ammonium carbamate into NH3 and CO2 and of their stripping and a subsequent operative step of their recondensation into ammonium carbamate that is recycled to the synthesis reactor, the said reaction mixture obtained from the reaction between ammonia and carbon dioxide being pumped to the operative steps of decomposition and stripping.

Abstract: A process for urea production comprises a first process step in which ammonia (7) and carbon dioxide (6) are obtained, subjecting natural gas (1) to reforming treatments (12, 14), and a second step of urea (8a) production from such ammonia (7) and from carbon dioxide, through a formation of a solution comprising urea and ammonium carbamate in a urea synthesis reactor (20) and a subsequent decomposition of the ammonium carbamate and. urea recovery, the process comprises the steps of:—treating combustion smokes (5) comprising carbon dioxide with an aqueous solution (9a) comprising a part (7b) of such ammonia (7), obtaining an aqueous ammonium carbamate solution (9c);—supplying the solution (9c) thus obtained to the second process step.

Abstract: An apparatus for treating highly corrosive agents comprises a tube bundle (14) heat exchanger (10), structured to carry out a heat exchange between two fluids one of which is highly corrosive and flowing inside of said tube bundle (14).

Abstract: A method for the production of synthesis urea from liquid ammonia and gaseous carbon dioxide, comprising the step of feeding separate flows (6, 8) of liquid ammonia and gaseous carbon dioxide in continuous to a substantially vertical or horizontal column synthesis reactor (1), is distinguished in that the feed of liquid ammonia is split up into at least two consecutive sections (Z1-Z7) of said column.

Abstract: A method for obtaining urea prills in a prilling tower (1) comprising the step of making a plurality of melt urea droplets to fall from a urea melt distributing device (4) towards an urea prills collecting bottom (6) of the prilling tower, further comprises the step of cooling the collecting bottom (6).

Abstract: A method for the production of synthesis urea from liquid ammonia and gaseous carbon dioxide, comprising the step of feeding separate flows (6, 8) of liquid ammonia and gaseous carbon dioxide in continuous to a substantially vertical or horizontal column synthesis reactor (1), is distinguished in that the feed of liquid ammonia is split up into at least two consecutive sections (Z1-Z7) of said column.

Abstract: In a process for decomposing a carbamate aqueous solution coming from a urea recovery section of a urea production plant at a predetermined temperature by indirect heat exchange with a heating fluid having a different predetermined temperature, the temperature difference between said carbamate aqueous solution and said heating fluid is reduced to a value not higher than 70° C.

Abstract: A process for urea production in a synthesis loop based on CO2 stripping is distinguished by the fact that at least part of a flow recycle carbamate is sent to a treatment of carbamate decomposition and removal of free ammonia to obtain a vapour flow containing CO2 and NH3 with minimum content of water, and a weak water carbamate solution sent back to a urea recovery unit URS and being at least part of above vapour flow containing CO2 and NH3 with minimum content of water directly fed to the bottom zone of a reaction space.

Abstract: In a process for decomposing a carbamate aqueous solution coming from a urea recovery section of a urea production plant at a predetermined temperature by indirect heat exchange with a heating fluid having a different predetermined temperature, the temperature difference between said carbamate aqueous solution and said heating fluid is reduced to a value not higher than 70° C.

Abstract: A process for urea production in a synthesis loop based on CO2 stripping is distinguished by the fact that at least part of a flow recycle carbamate is sent to a treatment of carbamate decomposition and removal of free ammonia to obtain a vapour flow containing CO2 and NH3 with minimum content of water, and a weak water carbamate solution sent back to a urea recovery unit URS and being at least part of above vapour flow containing CO2 and NH3 with minimum content of water directly fed to the bottom zone of a reaction space.

Abstract: A process for reducing the residual free ammonia emissions from an urea production plant comprises the step of feeding a gas flow comprising carbon dioxide (8) to a melt urea flow (3) coming from the concentration section (13) of the plant.