Controlling Particulate Emissions from Ammonium Nitrate Prill Production

Keywords: Ammonium nitrate, prill tower, particulate emissions, mist eliminators, prill tower scrubbers, emission control technology.

In 2003, Ultrafertil in Cubatão, Brazil, (currently Vale Fertilizantes) was faced with impending new local air emissions regulations. In order to meet these new regulations, the company needed a solution to reduce the visible plume and keep the ammonium nitrate (AN) concentration in the prill tower exhaust to less than 10 mg AN/Nm³ (dry basis) and the ammonia (NH₃) concentration to less than 15 mg NH₃/Nm³ (dry basis).

After careful consideration of all options available (which included switching the entire manufacturing process to a granulation process), the company partnered with MECS, Inc. (MECS) to retrofit the existing plant with MECS ^® Brink ^® mist eliminator technology. In order to meet local regulations, the new control equipment was designed to handle the full prill tower exhaust flow, resulting in the largest AN prill tower scrubber system in the world.

A retrofit project of this magnitude presented several challenges, including logistics, equipment size, reliability, and process control. All of these challenges will be discussed in detail, as well as the solutions found to resolve them.

In 2013, the new AN prill tower scrubbing system was commissioned utilising Brink mist eliminator technology. After start-up, measured ammonium nitrate stack levels were well under the regulation requirement, ammonia stack level was non-detectable, and the prill tower exhaust plume was no longer visible. This paper discusses the entire project from start to finish, from technology selection to startup and beyond.

J H B Guimarães^a, S Ziebold^b, J Hanekom^c

^a Vale Fertilizantes, Cubatão, São Paulo, Brazil.

^b MECS, Inc., St. Louis, Missouri, USA.

^c MECS BVBA Europe/Africa, Brussels, Belgium.

19 pages, 9 figures