A discussion about the causes for a change in urea product colour. Stainless steels exposed to carbamate containing solutions in the urea synthesis section can be kept in a passive state by adding a minimum amount of oxygen. If the oxygen content drops below this minimum, active corrosion starts, which can be identified by a shiny silver colour on the surface.
Preservation covers the method of protection and preventative maintenance carried out on equipment and systems before and after they are put into use. In power plants, fertilizer units and refineries, expensive equipment like turbines, chillers, power generators, boilers, condensers, panels etc. begin to rust and corrode when in storage or during shutdown or even when in operation due to the presence of excess moisture in the air. Proper downtime procedures are extremely important. In this discussion, preservation and its importance is discussed by urea plant experts.
The waste water treatment section in a urea plant processes the water containing NH3-CO2 and urea from the vacuum system in the evaporation section. This discussion looks into the possible root cause of problems with the concentration in the waste water section feed tank of a urea plant and the off-grade condensate produced.
In a urea plant, too much carbamate solution recycle back to the synthesis section will increase the amount of water in the synthesis and will negatively influence the reactor conversion figures. Fouling in the recirculation section can sometimes cause these operational problems, but how can fouling be identified as the root cause of a problem?
A discussion into the possible causes of a temperature drop of the HP stripper outlet of a Saipem urea plant after start-up.
Once a flange connection in the high pressure urea synthesis section leaks it is almost impossible to stop by re-tightening the bolts. This raises the question whether the flange connection should be insulated.
Ammonium carbamate is very corrosive under the synthesis conditions in a urea plant. The various process licensors have developed different solutions to assure sufficient safety and reliability levels, but what is the best material?
A discussion defining the role of the stripper and decomposer in a urea plant and how they differ.
Hot prills can easily cause caking which leads to lump formation and consequently dust formation when these lumps are crushed. This all leads to poor product quality and customer complaints, but how can hot prills be avoided?
The scraper in a prilling tower rotates above the floor of the tower and moves the prills from the bottom of the prilling tower to the conveyor belt. Under certain conditions, the scraper can get clogged and requires cleaning, but how can this be done safely?