The present invention discloses a method for recycling urea in the process of separating and purifying unsaturated substances through a urea adduction method. The method comprises the following steps: liposoluble substances containing target unsaturated components are used as raw materials, and subjected to urea adduction, crystallization and filtration to produce a filtrate, from which the specific unsaturated components are obtained; the urea adduct is dissolved in a polar solvent, and after the adducted adducts are layered and released, adding a certain solvent to the urea solution to adjust the polarity, then cooling for crystallization, and recycling the urea. The method can realize complete release of the adducted components and recycling and reuse of urea, and the process is simple, the recovery rate is high, and the adduction effect is not influenced when recycling urea for reuse, and the production cost of the urea adduct is reduced, thus alleviating the adverse impact of urea discharges on the environment.

A distribution chamber suitable for distributing a liquid stream to a plurality of pipe openings distributed over a planar surface. The distribution chamber includes three perforated plates. A method to distribute a liquid stream to a plurality of pipe openings, a method to decompose ammonium carbamate from an aqueous solution comprising ammonium carbamate and a method to produce a concentrated aqueous urea solution from a diluted aqueous urea solution.

A distribution chamber suitable for distributing a liquid stream to a plurality of pipe openings distributed over a planar surface. The distribution chamber includes three perforated plates. A method to distribute a liquid stream to a plurality of pipe openings, a method to decompose ammonium carbamate from an aqueous solution comprising ammonium carbamate and a method to produce a concentrated aqueous urea solution from a diluted aqueous urea solution.

The application provides in an aspect a process for producing urea in a urea plant comprising a high pressure synthesis section comprising a reactor, wherein the process comprises reacting NH.sub.3 feed and CO.sub.2 feed under urea formation conditions in said reactor to form a urea synthesis solution comprising urea, water, carbamate and ammonia, wherein the process further comprises contacting a carbamate-containing liquid stream with an equipment part of said high pressure synthesis section that is made of a ferritic steel alloy.

The application provides in an aspect a process for producing urea in a urea plant comprising a high pressure synthesis section comprising a reactor, wherein the process comprises reacting NH.sub.3 feed and CO.sub.2 feed under urea formation conditions in said reactor to form a urea synthesis solution comprising urea, water, carbamate and ammonia, wherein the process further comprises contacting a carbamate-containing liquid stream with an equipment part of said high pressure synthesis section that is made of a ferritic steel alloy.

A bottom chamber of a stripper (or bottom liquid holder) including a vortex breaker, a blocking plate and a guiding plate. A stripper, a urea HP stripper, a urea plant, a method for operating a stripper and a method for producing a solid, particulate urea-based composition.

A bottom chamber of a stripper (or bottom liquid holder) including a vortex breaker, a blocking plate and a guiding plate. A stripper, a urea HP stripper, a urea plant, a method for operating a stripper and a method for producing a solid, particulate urea-based composition.

The invention relates to a method for producing a urea solution with a target urea concentration using water flows recovered from the urea production process. At least part of the water flows recovered from the urea production process are only partially purified to produce the urea solution. The invention further relates to a process condensate treatment plant to implement the method for producing a urea solution with a target urea concentration, and a urea production plant comprising such process condensate treatment plant.

The invention relates to a method for producing a urea solution with a target urea concentration using water flows recovered from the urea production process. At least part of the water flows recovered from the urea production process are only partially purified to produce the urea solution. The invention further relates to a process condensate treatment plant to implement the method for producing a urea solution with a target urea concentration, and a urea production plant comprising such process condensate treatment plant.

A urea production process comprising concentrating a first urea solution in a first vacuum evaporator in an evaporation section to give a urea melt and a first vapor, and condensing the first vapor in a first condensation section, wherein the first condensation section is a chilled condensation section, and a urea production system comprising the chilled condensation section.