Single Step Filtration

Single step filtration is generally the most economical solution when it is not practical to recycle the residues.

solvair-schema-single-step-filtration


The finely ground sodium bicarbonate is injected into the flue gases at a temperature higher than 140°C in the filter. A contact reactor is used especially when a residence time of one second of the reagent in the flue gas cannot be obtained. The residues from the filter (salts from the neutralisation of the acids, excess carbonate, adsorbent) are collected in the filter, together with the fly ash. 

The purification performances and sodium bicarbonate consumption are identical to those in the double step filtration configuration. 

Recycling the purification residues is more difficult as the residues collected in the filter contain a mix of fly ashes and residual sodium chemicals. 

Single step filtration is generally the most economical solution when it is not practical to recycle the residues.