Physical absorption of volatile organic compounds by spraying emulsion in a spray tower: Experiments and modelling

Abstract

Absorption Volatile organic compound (VOC) Emulsion Gas-liquid Mass transfer coefficient a b s t r a c t This study outlines a volatile organic compounds (VOCs) removal spray tower consisting of an empty cylindrical vessel and nozzles spraying an oil/water emulsion into the vessel. Spraying an emulsion into a spray tower absorbs both lipophilic and hydrophilic compounds, facilitates oil transport, improves the interfacial area (oil coats water droplets) and increases the turbulent flow regime enhancing mass transfer. Toluene was chosen as the synthetic lipophilic pollutant. The choice of the organic absorbent, silicone oil (47v350 Rhordorsil ® ), was made by considering several properties: thermal and mechanical stability, non-biodegradable nature, insolubility in water and low value of Henry's constant. Gas-liquid mass transfer and the hydrodynamics of the gas-liquid contactor were thoroughly investigated. It was observed that emulsion spraying allowed the dual absorption of hydro-and lipophylic VOCs (efficiency around 90% for both) and strongly enhanced the liquid mass transfer coefficient. Finally, a model describing the efficiency of the process as a function of time was developed. The predicted values are in good agreement with the experimental results.

Absorption of toluene by vegetable oil–water emulsion in scrubbing tower: Experiments and modeling

“…Because toluene is not absorbed in water (Tatin et al, 2015), we had to consider only the oil interfacial area involved in the mass transfer operation. We introduced an oil cover ratio (D which is directly linked to the oil:water emulsion ratio if we assume an isotropic emulsion.…”

“…Other works have been published on the absorption method using a siloxane/water emulsion (Dumont et al, 2012), or silicone oil/water emulsion (Tatin et al, 2015). Most of these studies operated in a semi-batch system using recirculation of the emulsion without any regeneration of the VOC-saturated oil.…”

“…However, two columns are necessary and the high viscosity of oil makes the energy expenditure prohibitive for this application (Darracq et al, 2010). The use of a water/oil emulsion is an alternative that reduces the number of towers of a process (Tatin et al, 2015) and thus reduces the initial investment in equipment and the cost of energy supplies while increasing the contact surface area available for gas-liquid exchange and the amount of VOCs that can be treated in a counter-current packed system (Dumont et al, 2011).…”

A Sophomore's Exposure, Interest, and Aspirations in Research on Current Practices of Volatile Organic Compound Removal

“…Traditional VOC retrieval procedures are expensive and dependent on several variables, such as temperature, gas flow rate and pollutant concentration (Tatin et al, 2015). Conventional VOC removal requires resources and materials not only to maintain a high temperature, high pressure, and sometimes adiabatic system but when replacing and discarding spent catalysts.…”

“…Alternatively, Tatin et al (2015) analyzed the effectiveness of using a water/silicone oil emulsion to capture VOCs in spray towers. In this study the researchers found that the emulsion was up to 90% effective at VOC removal.…”