The treatment of waste gas from fertilizer production - An industrial case study of long term removing particulate matter with a pilot unit

Abstract

This manuscript covers an on site industrial case study focused on the dry filtration of particulate matter (PM) from the waste stream of fertilizer production. In the industrial plant producing fertilizers, it was necessary to exchange the old wet scrubber with new cleaning equipment for PM disposal. A filter unit with bag filters and pulse-jet cleaning was chosen as the new waste-free technology. Unfortunately, one step in the production involves granulation with steam and water, therefore the waste gas stream was quite humid. Filter bags captured 10 g and 40 g of H2O/kg of dry gas for GR-SA and NPK fertilizers respectively. Due to dry filtration feasibility concerns, a long term pilot unit test was conducted. The impact of operating conditions, especially the inlet stream temperature and humidity was evaluated. A inlet temperature 100 °C for GR-SA and 110 °C for NPK fertilizers was necessary to prevent clogging of the filter bags. We found that different cleaning pulses periods and pulse pressures have a minimum impact on the filter pressure difference (ΔP). Based on the results of the pilot test, recommendations for usable technological conditions were given, in order to avoid problematic deposits on filter material associated with increased ΔP. In addition to this, a straightforward comparison method was proposed in this paper for filter clogging according to ΔP between cleaning pulses.