Advances in Gas Cleaning Technology in the Fertiliser Industry

Keywords: Gas cleaning, Scrubbers, Fertiliser production, Gas filtration

The fertiliser industry has earned recognition for having contributed directly to the increase in world grain yields in the past century. Based on a conservative estimate of the world population growth, total fertiliser use in the future is expected to grow to more than 180 million tonnes from the current level of 145 million tonnes. In U.S.A. and other countries the industries have always been challenged to meet the current and future air quality emissions standards set by local, state and federal governments under the Clean Air Acts and other regulations.

Accordingly, less polluting technologies emerged by way of reducing SOx and NOx in exhaust air from plants producing sulphuric and nitric acids, ammonia, phosphate and nitro-phosphate in order to minimise ‘acid rain’ problems in the atmosphere.

Fluorine (F) emissions have similarly been lower from phosphoric acid, di- and mono-ammonium phosphate and granular triple or single super-phosphate plants at or below 10.0g F/t P₂O₅ input through improved scrubber technology and control mechanisms.

Further advances in technology for developing ladder-like structured mono-filament media as a packing material for absorption and mist elimination purposes have reduced F emission levels from 10.0 to 6.5g F/t P₂O₅ in the industry at present. Emissions from urea prilling have been reduced to as low as 3 ppm urea.

This paper will discuss about gas cleaning equipment in general and advances in cross/semi-cross flow scrubber technology with Kon-Tane, B-Gon and Aerosep in particular, as media for prevention of air pollution from the fertiliser industry.

George (Chris) Pedersen, Kimre, Inc., Florida, USA

P. K. Bhattacharjee, Consultant.

30 pages, 16 figures, 3 tables, 7 refs.