Use of Simulator for Decision to Reuse of Industrial Effluents

Abstract

The need to reduce operational inefficiency because no generation of effluent encourages industries to search improvements in the procedures and technologies. However, in case that is not technically or economically feasible, the water reuse is a good option. The removal of volatile organic compounds (VOC) in liquid streams at a nitrogen fertilizer industry is carried out in a stripper that generates treated condensate that can be reused. The present work aims at the reuse of the treated condensate to produce steam and it was conducted according to methodology: collection and reconciliation of data in the industrial plant; simulation operating conditions and changed conditions for the most contaminant removal; tests in loco and analysis of physicchemical parameters to assess the quality of the treated condensate. The simulation was performed in steady state for two scenarios: the first one using operating conditions with vapor pressure between 3.2 bar and 6.0 bar and a flow rate of saturated steam between 1.5 t/h 5.0 t/h; the second simulation scenery considered the removal of the D stream process of the stripper, that has a high concentration of ammonia and methanol. In the first scenario, it was observed by manipulating of the pressure to 6.0 bar and steam flow to 2.0 t/h make better the removal ammonia efficiency. For the second scenario has also greater efficiency in the removal of both ammonia and methanol. The tests in loco and physic-chemical analysis showed that removal of the D stream process can enable the of reuse to make up for water in boiler to produce steam of until 41 bar after additional treatment, reducing the conductivity and iron concentration. The reuse of this treated condensate provides an economic gain of approximately US$ 500 000 each year, reducing the cost with the use of demineralized water and wastewater treatment. The use of the simulator allowed studying different scenarios, to reduce the number of experimental tests in loco and establishing routes for reuse industrial wastewater.