Fertiliser plants have many issues to be solved regarding levels of emissions (primarily dust and ammonia), which require different types of technical solutions and products.
This paper describes and reviews the various technologies that are available to control these emissions. The principles of operation of each type of control approach is described, along with a comparison between those technologies in terms of efficiency removal and pressure drop:
• Demisters, candles, and meshpad and structured mist eliminators.
• Jet venturi scrubbers.
• Wet electrostatic precipitators.
The paper also includes a case study, describing the first installation of wet electrostatic precipitator technology in the fertiliser industry. In 2015 Lovochemie a.s., a fertiliser company based in Lovosice, Czech Republic, was faced with new local air emissions regulations applying to their new universal granulator, producing ammonium nitrate, ammonium sulphate and calcium ammonium nitrate. The company was required to keep the limits for dust to less than 6 mg/Nm3 and for ammonia to less than
4 mg/Nm3. Lovochemie was also required to achieve ‘zero opacity’ as the main target for the clean gas.
After six months of on-site tests in 2015, using a Wet Electrostatic Dust Separation (WESP) pilot plant, where the dust concentration was analysed before and after the installation of our equipment, the client came to the conclusion that WESP was the right choice for this application. A final hazard and operability study (HAZOP) certified the full reliability and safety of this technology.
At the end of 2015 the contract was signed. The full scale plant was commissioned during the first quarter of 2017 and started to operate in May 2017.
After start-up, detected levels of both dust and ammonia were much lower than the regulatory requirements, and the plant is still successfully working to the full satisfaction of Lovochemie.