Ammonia Casale Sa

Other

Urea Casale Sa

Methanol Casale Sa

Ammonia Casle S.a.

Umberto Zardi

Giorgio Pagani

Ermanno Filippi

Enrico Rizzi

Ettore Comandini

A horizontal chemical reactor comprises at least one catalytic bed (-) arranged horizontally in the reactor and comprising a lower gas-permeable wall () for gas outlet, and a holding element () of the at least one catalytic bed.

Horizontal chemical reactor, in particular for methanol synthesis

In a process for the production of urea, substantially pure ammonia and carbon dioxide are reacted in a reaction space ( ) from which comes out a reaction mixture subjected to stripping ( ) to obtain a partially purified mixture sent to a urea recovery section ( ). From the recovery section ( ) it is obtained a dilute carbamate solution, which is subjected to stripping ( ) with recycling of vapors to the reaction space ( ) after condensation ( ). This process achieves high conversion yield with reduced energy consumption and low implementation costs.

Process and plant for the production of urea with high conversion yield and low energy consumption

A process for the combined production of ammonia and urea of the type comprising an ammonia synthesis reactor ( ), a urea synthesis reactor ( ) and a urea recovery section ( ) stands out for the fact of submitting at least a part of a flow comprising carbamate in aqueous solution coming from the urea recovery section ( ) to a partial decomposition treatment, to obtain a flow comprising ammonia and carbon dioxide in vapor phase and a flow comprising diluted carbamate in aqueous solution, which is fed together with a gas flow comprising hydrogen, nitrogen and carbon dioxide, preferably obtained by hydrocarbons steam reforming, and a flow comprising ammonia coming from the ammonia synthesis reactor ( ) to a carbamate synthesis section ( ), where ammonia and carbon dioxide are caused to react, to obtain a flow comprising carbamate in aqueous solution and a gas flow comprising hydrogen and nitrogen. The flow comprising carbamate in aqueous solution is then sent to the urea synthesis reactor ( ), while the gas flow comprising hydrogen and nitrogen is sent to the ammonia synthesis reactor ( ).

Process for combined production of ammonia and urea

The present invention relates generally an apparatus for uniformly mixing gaseous flows at different temperatures. In particular, a preferred embodiment of the present invention relates to a heterogeneous exothermic synthesis reactor including a plurality of superimposed catalytic beds wherein at least one of the beds is provided with a gas permeable wall for outlet of a hot gas flow. In this embodiment, a baffle extends below and parallel to the gas permeable wall, thereby defining an air space to collect the hot gas flow. An annular opening is provided for outlet of the hot gas flow from the air space defined between the baffle and a side wall supporting the beds associated with the reactor and a perforated distributor for cooling a gas flow supported below said baffle at a predetermined distance from the annular opening. Further, the air space which collects the hot gas flow has a constant thickness in correspondence with the annular opening and the ratio of the width of the annular opening to the thickness of the air space is between 0.2 and 1.

Mixing assembly for gaseous flows at different temperatures, in particular for heterogeneous exothermic synthesis reactors

Process for the revamping of urea production plants for the synthesis of ammonia (NH3) and carbon dioxide, with a stripping section with NH3, in which the process carries out with differentiated yields, a majority reaction a) between highly pure reagents and a reaction b) between less pure substantially recycled reagents, according to European Patent No. 91116297.2/0479103. According the invention, the urea solution is now fed upstream the stripping section and a reactor with heat removal is utilized. Advantageous, the production capacity of the existing reactor is reduced, with respect to the projected one, in a quantity of 35% to 5%, preferably from 20% to 10%, in favor of the capacity of the &ldquo;once-through&rdquo; reactor.

Process for the revamping of urea synthesis plants consisting of a stripper with ammonia

An improved process for urea production as well as a method of retrofitting a pre-existing urea plant based on the Stamicarbon process are disclosed. According to the invention, a high yield reaction space fed by highly pure reagents (NH3 and CO2) and a separating section of the solution leaving the high yield reaction space are added to the pre-existing urea plant, means being provided for recirculating ammonia and carbammate solutions obtained in the separating section to the added high yield reaction space and to the pre-existing reactor respectively.

Process for urea production

Mixing assembly for gaseous flows at different temperatures, in

In a method of modernizing a heterogeneous exothermic synthesis reactor (1) of the type comprising an external shell (2), in which at least one catalytic bed (15, 16, 17) is supported, the catalytic bed (15, 16, 17) is connected to an external boiler (21), for generating high pressure steam, by means of a reacted gas outlet nozzle (4) and a conduit (29) extending in said nozzle (4) thereby forming an annular airspace (30). Advantageously, the airspace (30) defines an outlet flowpath of the gases cooled in the boiler (21) which avoids overheating of the nozzle (4).

Method of retrofitting a heterogeneous exothermic synthesis reactor

Method for the protection of the internal walls of the shell of Braun type converters, transformed into axial-radial reactors with insertion of a cartridge and a cylindrical perforated wall, characterized by the fact that cooling gas is circulated (FLU) at temperatures between 250.degree. and 300.degree. C. in the airspace (I) between cartridge (C) and (P).

Heterogeneous synthesis method and apparatus including wall temperature

Process and apparatus for the revamping of urea production plants for the synthesis of ammonia (NH3) and carbon dioxide, with a stripping section with NH3, in which the process carries out with differentiated yields, a majority reaction a) between highly pure reagents and a reaction b) between less pure substantially recycled reagents. According to the invention, the urea solution is now fed upstream the stripping section and a reactor with heat removal is utilized. Advantageously, the production capacity of the existing reactor is reduced, with respect to the projected one, in a quantity of 35% to 5%, preferably from 20% to 10%, in favor of the capacity of the 'once-through' reactor.

Process and apparatus for the revamping of urea synthesis plants

A method for 'in-situ' modernization of a reactor for effecting heterogeneous exothermic synthesis reactions, especially of the so-called Kellogg type, including the preliminary step of providing at least three radial or axial-radial catalyst beds (11, 12, 13), includes the steps of providing a first gas/gas heat exchanger (18) between the first (11) and second (12) catalyst beds and a second gas-gas heat exchanger (29) in the third catalyst bed (13). Thanks to the provision of two exchangers (18, 29) for cooling of the gases flowing between the catalyst beds by means of indirect heat exchange, the present modernization method allows to achieve a reactor with a high conversion yield.

Method and apparatus for in-situ modernization of a heterogeneous

Process for the industrial synthesis of urea, by reacting ammonia (NH.sub.3) and carbon dioxide (CO.sub.2) in at least one reaction space, at high pressures and temperatures and by recirculating at least part of the non-reacted products obtained in a recovery section, characterized by the fact that the following takes place : a synthesis reaction A) between highly pure reagents, and a synthesis reaction B) between less pure reagents, substantially recycled from the said recovery section, the reaction A) being either of adiabatic type A1) or with partial reaction heat removal A2).

Process and plant for the production of urea with differentiated yield

Process for the industrial synthesis of urea, in which ammonia (NH3) and carbon dioxide (CO2) are reacted in at least one reaction space SR at high temperature and pressure and the unreacted materials are treated in a recovery section, said synthesis comprising: a) a reaction between highly pure reagents; and b) a reaction between less pure reagents substantially recycled from said recovery section, characterized by the fact that reaction stage A for high Yield majority synthesis (HEPC), between very pure reagents, operating at a higher pressure (Pmax) for example above 300 kg/cm2 abs and preferably at about 400 kg/cm2 abs, is followed by a flash stage F1 operating at pressures lower by at least 40% than said pressure (Pmax) preferably lower than 200 kg/cm2 abs, the gas effluent GF1 from the above-mentioned flash stage F1 being fed to reaction stage B for minority synthesis of less pure reagents operating at a pressure below 200 kg/cm2 abs, while the liquid effluent EL1 from the abovementioned flash stage, together with effluent EB from stage B of minority reaction operating in parallel with majority reaction stage A, feeds a recovery section RE consisting of two decomposition stages D1 and D2 operating in series: the first D1 being at a pressure lower than 100 kg/cm2 abs preferably at 50 kg/cm2 abs; the second D2 operating at a pressure lower than 50 kg/cm2 abs preferably at 20 kg/cm2 abs.

Process and plant for the production of urea

Improved process to convert in situ conventional reactors with four catalytic beds with axial flow and with intermediate quenching (Kellogg reactor), Third and fourth original beds are combined thus obtaining a reactor with three beds through which the synthesis gas now flows with a substantially radial flow.

Growing community of inventors

Breganzona, Switzerland

Umberto Zardi