Our latest development is the Avancore® urea process, which further enhances our proven Urea 2000plus™ technology. This process is based on zero oxygen intake and is therefore intrinsically safe. In the plant height chart the Avancore® technology is shown in a configuration for large capacities plants with a pool condenser and vertical high-pressure reactor.
It reduces the required plant height to just 25m. This has naturally brought down investment costs considerably. However the Avancore® process is also available with a pool reactor for urea plants up-to medium capacities.
Customers can now choose among basic synthesis concepts that use either Avancore® or the Urea 2000plus™ technology.
The Avancore urea process works as follows: Ammonia and carbon dioxide are introduced to the high-pressure synthesis using a high-pressure ammonia pump and a carbon-dioxide compressor. The ammonia, together with the carbamate solution from the downstream recirculation section, enters the pool condenser.
The major part of the carbon dioxide enters the synthesis through the high-pressure stripper counter-current to the urea/carbamate solution leaving the reactor. On the shell side, the high-pressure stripper is heated with steam. The off-gas of the high-pressure stripper, containing the carbon dioxide, together with the ammonia and carbon dioxide resulting from dissociated carbamate, is fed into the pool condenser.
The minor part of the carbon dioxide entering the synthesis as a feed, travels into the bottom of the urea reactor, thus producing sufficient heat for the endothermic urea reaction.
In the pool condenser, ammonia and carbon dioxide are condensed to form carbamate and a substantial part of the conversion to urea is already established here. The heat released by condensation and subsequent formation of carbamate is used to produce re-usable low-pressure steam.
View Avancore® urea process
Downstream from the pool condenser, the urea-carbamate liquid enters the vertical reactor, if required, located at ground level. Here, the final part of the urea conversion takes place. The urea solution then leaves the top of the reactor, all by gravity flow (via an overflow funnel) before being introduced into the high-pressure stripper. Gases leaving the urea reactor are directed to the pool condenser.
Gases leaving the pool condenser are fed into the scrubber operating at a reduced pressure. Here, the gases are washed with the carbamate solution from the low-pressure recirculation stage. The enriched carbamate solution is then fed into the pool condenser. This enriched carbamate flow contains no more water than in earlier generations of Stamicarbon CO2-stripping plants, meaning that the conversions in the synthesis section are as high as ever. Inert gases leaving the scrubber at reduced pressure containing some ammonia and carbon dioxide are then released into the atmosphere after treatment in a 4-bar absorber.
