Experimental Assessment of Water Sprays Utilization for Controlling Hydrogen Sulfide Releases in Confined Space

This paper reported the utilization of water spray for controlling H2S release in a confined space, which is especially important in industry. A typical spray tower was modified to simulate the confined space for people's enterable routine operation (e.g., pump room), in which the dilution capacity of water sprays can also be evaluated. This work consists of two parts: the first part focuses on the influences of different operating conditions on chemical dilution capacities of water sprays in mechanisms; the second one is comparison between two nozzle configurations for evaluating their feasibilities of practical application. Water sprays express eligible performance for H2S release control even though their dilution capacity was weakened at high gaseous concentrations and rates of releases. The presence of Na2CO3can significantly improve absorption effectiveness of H2S in water and the optimal Na2CO3additive was found to be 1.0 g·L−1in this test. Compared with Na2CO3, adjusting water flow rate may be an effective strategy in enhancing dilution capacity of water sprays due to the fact that larger flow rate led to both less dilution time (TD) and dilution concentration (CD). Furthermore, multinozzle configuration is more efficient than single-nozzle configuration under the same water consumption.

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.