Process for purifying gaseous effluents

摘要

A process for purifying gaseous effluents containing aldehydes comprises submitting the gaseous effluents to the simultaneous action of SO2 and NH3 followed by washing with water. The ratio of the required quantities of NH3 and SO2 is between 2:1 and 3:1. When the gas to be purified naturally contains NH3, as is for instance the case in rendering plants, the quantity of NH3 to be added to the gas is reduced accordingly. Conversely when the gas to be treated naturally contains SO2, the quantity of SO2 to be added to the gas is also reduced accordingly. The most favorable ratio would correspond to a pH of the washing waters of between 7 and 7.5.