Co-current and counter-current spraying of odour-neutralizing products.

A lab-scale pilot plant was developed in order to measure the efficiency of some odour-neutralizing products for the removal of odorous compounds. Experiments were carried out on gas and liquid flows in two configurations: co-current and counter-current, which differ in the values of the drop diameter and the contact time, leading to different behaviours between highly water-soluble compounds like ammonia and other compounds like sulphurous compounds. Mass transfer was shown to be modified by the presence of neutralizing products as a result of their pH and surface tension. Few chemical reactions, except for acidic or basic ones, could be highlighted. Olfactometric analyses were carried out and showed that, because of possible confusion between odours caused by the neutralizing product and odours caused by the by-products, it was difficult to conclude that an obvious relation existed between physico-chemical and olfactometric efficiencies.