Influence of liquid and gas flow rates on sulfuric acid mist removal from air by packed bed tower

The possible emission of sulfuric acid mists from a laboratory scale, counter-current packed bed tower operatedwith a caustic scrubbing solution was studied. acid mists were applied through a local exhaust hood. theemissions from the packed bed tower were monitored in three different categories of gas flow rate as well as threeliquid flow rates, while other influencing parameters were kept almost constant. air sampling and sulfuric acidmeasurement were carried out iso-kinetically using usepa method 8. the acid mists were measured by thebarium-thorin titration method. according to the results when the gas flow rate increased from 10 l/s to 30 l/s,the average removal efficiency increased significantly (p < 0.001) from 76.8 ± 1.8% to 85.7 ± 1.2%. analysis ofcovariance method followed by tukey post-hoc test of 92 tests did not show a significant change in removalefficiency between liquid flow rates of 1.5, 2.5 and 3.5 l/min (p = 0.811). on the other hand, with fixed pressure lossacross the tower, by increasing the liquid/gas (l/g) mass ratio, the average removal efficiency decreasedsignificantly (p = 0.001) from 89.9% at l/g of < 2 to 83.1% at l/g of 2–3 and further to 80.2% at l/g of > 3,respectively. l/g of 2–3 was recommended for designing purposes of a packed tower for sulfuric acid mists andvapors removal from contaminated air stream.