Suited for revamping of Total Recycle plants with capacity increase up to 100%
- CO2 conversion up to 80%
- Steam consumption 700 kg/MT urea
When the target is significantly to increase production - up to 100% above the nameplate capacity - Casale recommends switching to ammonia stripping technology. The existing HP section is modified by adding an HP stripper, a kettle-type HP condenser, an HP carbamate separator and a carbamate ejector. Depending on the required capacity increase, the existing reactor may be kept as it is or an additional reaction volume may be added downstream.
The CO2 conversion after revamping the HP section is in line with the typical value for ammonia stripping processes (80%) and much higher than in the original total recycle reactor (typically 60%). This means that the urea solution sent to the backend contains less carbamate and therefore, even in case of a very large capacity increase, only minor changes are needed.
Typical steam consumption after revamping is in the range of 700 kg/MT of urea, a value not far from that of a new ammonia stripping plant and noticeably better than that of the original unmodified total recycle plant.
Converting the HP section of existing total recycle plants to ammonia stripping technology is a well proven solution to significantly boost capacity and improve performance at a fraction of the cost of installing a new plant.