A new generation of urea granulation plants are planned for the USA over the next few years, with the first of these already in the construction phase. The principal motivation for the plants is low and sustainable natural gas prices, coupled with a very large domestic market.
Many of these plants are considering using an Indirect Cooler as the final step before the product goes to storage. The indirect cooler would replace the fluid bed cooler which to date has been the industry standard in new plant construction worldwide. The principal advantage of the Indirect Cooler is the much lower energy consumption compared to a fluid bed cooler.
Two factors lead to the smaller energy footprint: eliminating the fans, but much more important is the energy requirement for the chillers required to chill the air. In a comparison made for a recent project, this combined energy saving was approximately $500,000 per year.
Some of the companies planning to construct new plants in the USA already have direct experience operating Indirect Coolers in their plants and so regard this equipment as fully proven technology.
This paper was presented during the Nitrogen & Syngas Conference in February 2014 in Paris.