Embodiments pertain to a urea plant and to the operation of a urea plant in a reduced load mode. In embodiments, two evaporators in parallel are used, connected to a finishing section respectively to a melamine plant.

Embodiments pertain to a urea plant and to the operation of a urea plant in a reduced load mode. In embodiments, two evaporators in parallel are used, connected to a finishing section respectively to a melamine plant.

The disclosure pertains to urea production with, in series, an MP carbamate condenser for condensing at least urea synthesis section off-gas, gas/liquid separation giving a gas stream and a liquid stream, and a second carbamate condenser receiving off-gas from melamine production and said liquid stream.

The disclosure pertains to urea production with, in series, an MP carbamate condenser for condensing at least urea synthesis section off-gas, gas/liquid separation giving a gas stream and a liquid stream, and a second carbamate condenser receiving off-gas from melamine production and said liquid stream.

The disclosure pertains to a plant and process for the coupled production of urea and melamine. In an embodiment, a lean carbamate solution is supplied from the melamine production section to a recovery section of the urea production section. In an embodiment, enriched carbamate solution from the urea production section is supplied to an off-gas condenser of the melamine production section.

The disclosure pertains to a plant and process for the coupled production of urea and melamine. In an embodiment, a lean carbamate solution is supplied from the melamine production section to a recovery section of the urea production section. In an embodiment, enriched carbamate solution from the urea production section is supplied to an off-gas condenser of the melamine production section.

Disclosed is a process for the integrated production of urea and melamine. A urea production zone produces a urea synthesis stream comprising urea, water and ammonium carbamate. This stream is subjected to processing, preferably involving stripping, so as to separate an aqueous urea stream from residual dissociated carbamate vapor comprising ammonia, carbon dioxide, and water. The urea is fed to a melamine synthesis zone and subjected to melamine forming conditions so as to form melamine and off-gas comprising carbon dioxide and ammonia. The dissociated carbamate vapor and the melamine off-gas are subjected to combined condensation so as to form a dilute melamine off-gas condensate.

Disclosed is a process for the integrated production of urea and melamine. A urea production zone produces a urea synthesis stream comprising urea, water and ammonium carbamate. This stream is subjected to processing, preferably involving stripping, so as to separate an aqueous urea stream from residual dissociated carbamate vapor comprising ammonia, carbon dioxide, and water. The urea is fed to a melamine synthesis zone and subjected to melamine forming conditions so as to form melamine and off-gas comprising carbon dioxide and ammonia. The dissociated carbamate vapor and the melamine off-gas are subjected to combined condensation so as to form a dilute melamine off-gas condensate.

An integrated process for the synthesis of urea and melamine, wherein: urea is synthesized with a stripping process in a high-pressure synthesis loop comprising a reactor, a stripper and a carbamate condenser, and the urea solution leaving said stripper is sent to a recovery section to produce a concentrated urea product and a recovered carbamate solution; at least part of said urea product is converted to melamine, and the off-gas from the synthesis of melamine are recycled to the urea synthesis by mixing with the gas phase from the stripper and with said recovered carbamate solution, thus forming a mixed flow which is then condensed in said carbamate condenser, and the condensate is eventually directed to the reactor.

An integrated process for the synthesis of urea and melamine, wherein: urea is synthesized with a stripping process in a high-pressure synthesis loop comprising a reactor, a stripper and a carbamate condenser, and the urea solution leaving said stripper is sent to a recovery section to produce a concentrated urea product and a recovered carbamate solution; at least part of said urea product is converted to melamine, and the off-gas from the synthesis of melamine are recycled to the urea synthesis by mixing with the gas phase from the stripper and with said recovered carbamate solution, thus forming a mixed flow which is then condensed in said carbamate condenser, and the condensate is eventually directed to the reactor.