Economy of scale is driving plant capacities higher and higher. Starting some fifty years ago with 70 mtpd, the current trend in urea plant capacities shows a continuous increase in larger capacities from 3000 mtpd some ten years ago to nearly 4000 mtpd currently.
At this moment (October 2010) Stamicarbon has six and Saipem one 3000+ urea plant in operation. During the next years another seven Stamicarbon and six Saipem 3000+ are expected to start production.
Debottlenecking technologies are an important tool to make larger plant technologies proven with limited risks. The Yara Canada first debottlenecking project for example initiated the row of 3000+ urea plant capacities.
Both Saipem as well as Stamicarbon have performed a preliminary design to confirm the feasibility of 5000+ urea plants. It is expected that the first 5000+ mtpd urea plant will be licensed in the next coming decade.

2010 10 Brouwer UreaKnowHow.com World Scale Urea Plants.pdf