TH26453B - Urea preparation process - Google Patents

Abstract

DC60 Method for the preparation of urea The gas stream released during the synthesis of melamine, which contains ammonia. and mostly carbon dioxide sent back to karma How to make urea without further action And it is used there for the synthesis of urea, along with the gas stream produced by the process for high pressure melamine. which contains ammonia and carbon most of the dioxide which is sent to the high-pressure part of the urea separation machine. Method for preparing urea which the gas stream released during melamine synthesis which contains ammonia and mostly carbon dioxide It was returned to the urea process without further action. and is used there for the synthesis of urea. Along with the gas stream from the process for high pressure melamine. It consists mainly of ammonium and carbon dioxide. which is sent to the high-pressure part of the urea separation machine.

Claims (5)

1.Processes for in-machine urea preparation for urea separation Which has at least one high-pressure part, where the process includes a gas flow (13,213,313,413,513) process released from a high-pressure process for melamine production, which Operated with a pressure between 12.5 MPa and 80 MPa, to at least one high-pressure part of the aforementioned urea separation machinery, which was performed at a pressure between 12.5 MPa and 17.5 Mpa, where the current The gas has a temperature between 160 / C and 285 / C and is significantly composed of ammonia. And carbon dioxide 2. Process according to the claim clause 1, where the high pressure part where the gas current (13,213,313,413,513) thereof Was entered there It includes at least one type of reactor for urea (A), a separator (B), a condenser for carbamate (C), a pre-separator (R) installed between the reactors. And splitters, a flash container (Q) that was installed between And a condenser for carbamates or pipes between them 3. Process according to the claim clause 2, where the above-pressurized part contains a reactor for urea (A) at high pressure. And separators (B) using high pressure And the aforementioned gas current (413) is fed to the thermally-operated pre-separator (R). Which is located between the reactor for urea (A) and the aforementioned separator. 4. Process according to the claim 2, where the high-pressure parts of the urea separation machines include a condenser for the carbamate (C), the separator (B) and the path between them. And where the gas current (13,513) thereof Is fed to the condenser for the carbamate. Or go to the route between those machines 5. One of claim 1-4, where the urea separation machine includes the urea synthesis reactor (A) and the urea synthesis reactor. It works at a temperature of 160 C to 220 C 6. Process according to one of Clause 1-4, where that gas stream released from the melamine process There is a temperature between 175 C and 235 C. 7. Treatment according to one of the claims 1-4, where such gas flow (13,213,313,413,513) is released from the process for melamine having a pressure greater than 12.5. MPa 8. Process according to the Clause 7, where such gas flows (13,213,313,413,513) are released from the process for melamine pressurized. This is greater than that in the said high pressure, ranging from 0 to 10 MPa. 9. Process according to the claim. 7, where such gas flows (13,213,313,413,513) are released from the process for melamine pressurized. This is greater than the intensity in the aforementioned high-pressure parts from 0 to 2 MPa 1 0. urea separation machines for urea preparation, in which the machines have at least one high-pressure part assembled. Included at least one type of Reactor for urea (A), separator (B), the condenser for the carbamate (C) and the fluid flow path connected between the same And a path for melamine's output gas (13,313,513) to feed the exhaust gas stream that is released during high-pressure processing for melamine production. To the section with such high pressure Where the gas currents are significantly composed of ammonia and carbon dioxide 1 1. Machine according to the claim clause 10, where at least one such high-pressure part of which gas current (13,213,313,413,513) Was entered there This includes at least one type of pre-separator (R) that is installed between Reactor (A) and separator (B), flash vessel (Q) installed between the separator and condenser for the carbamate and the pipe between them 1. 2. Machine according to the claim clause 11, where the aforementioned high-pressure sections are equipped with a pre-separator (R) which operates in constant heat Installed between the reactor for urea (A) and separator (B) 1 3.Equipment for the synthesis of urea and melamine That includes: urea machines including high-pressure parts. Where there is a reactor for urea (A), a separator (B), a condenser for carbamate (C) and a fluid flow path connected between them; Machines for pressurized melamine including urea scrubbers (K) for receiving urea melts, reactors for melamine (L) and produce coolers (P). For the formation of melamine powdered And the fluid flow path that connects the same; And a gas outlet path (13,313,513) for feeding gas out of at least one reactor type for such melamine (M) and urea scrubbers (K). Directly to the said high-pressure section where pressure at or above the pressure that is typical for such high-pressure sections 1 4. Equipment according to the claim clause 13, where the high pressure part The said gas output (13,213,313,413,513) was fed there. Continue to include At least one type of pre-separator (R) installed between the reactor and the separator, the fresh container (Q) installed between the separator (B) and the condenser for the carbamate (C), and Pipes between those 1 5. Equipment according to the claim clause 14, where the gas outlet path (413) operates with a pre-separator (R) coupled with constant heat operation. Installed between the reactor for urea (A) and separator (B).