Novel Aqueous Foams for Suppressing VOC Emission

Abstract

Reducing volatile organic compound (VOC) emissions from crude oil/gasoline distribution and storage facilities is important in controlling environmental pollution and enhancing workplace safety. Stable aqueous foam formulations are developed to provide a mass transfer barrier to the emission of VOCs during loading of gasoline. Experiments are carried out in a bench-scale foam cell using liquid hexane as oil. The foam columns of 32 cm in height were able to suppress the plateau concentration of hexane vapors in the effluent by 87% under experimental conditions tested. Vapor suppression increased with foam height but was almost insensitive to liquid viscosity. These experiments are then upscaled from bench-scale to a vessel having an exposed surface area of roughly 2 orders of magnitude higher. Gasoline is used as oil in the upscaled experiments, and the concentrations of volatile hydrocarbons in the effluent are measured during oil loading. A 40-cm-thick foam column is found to reduce the emissions by 96% for foams prepared with deionized water and by 93.8% for foams prepared with 3.5 wt % NaCl brine for 10 h of oil loading.

Emissions of volatile organic compounds from crude oil processing – Global emission inventory and environmental release

“…As one of the recent regional standards for CVEs, the 40 CFR Part 60 entitled "Oil and Natural Gas Sector: Although there are regional policies restricting CVEs in Northern America, China and European nations, a comprehensive international treaty does not exist that can limit global emissions of VOCs from crude oil processing worldwide since the current regulations lack extensive controls over specific regions such as the Middle East, Africa and Latin America with high proven reservoirs of crude oil. There are measures in crude oil loading and transit sectors to control VOC emissions including vapour recovery systems (VRS) (Bennett, 1993), vapour emission control system (VECS) (Martens, Oldervik et al 2001), a sequential biotrickling-biofiltration , gelling material foam (Corino and Canevari 1972), polyurethane type foam (Sani and Mohanty 2008), a thin film of surface-active materials (Canevari and Cooper 1974), aqueous foam (Gautam and Mohanty 2004) and clay nanoparticle embedded aqueous foam Mohanty 2009, Sani, Gu et al 2012).…”

“…The recovery methods require considerable energy consumption and incineration by-product (CO2) . Suppression techniques aim at providing a barrier against VOCs by the use of gelling material foam (Corino and Canevari, 1972), polyurethane type foam (Sani and Mohanty, 2008), thin film of surface-active materials (Canevari and Cooper, 1974), aqueous foam (Gautam and Mohanty, 2004) and clay nanoparticle embedded aqueous foam Sani et al, 2012). Thus, the intended foam must have a high persistency over time, a low permeability towards VOCs, a desirable fluidity and acceptable flexibility to move (Gautam and Mohanty, 2004).…”

“…Suppression techniques aim at providing a barrier against VOCs by the use of gelling material foam (Corino and Canevari, 1972), polyurethane type foam (Sani and Mohanty, 2008), thin film of surface-active materials (Canevari and Cooper, 1974), aqueous foam (Gautam and Mohanty, 2004) and clay nanoparticle embedded aqueous foam Sani et al, 2012). Thus, the intended foam must have a high persistency over time, a low permeability towards VOCs, a desirable fluidity and acceptable flexibility to move (Gautam and Mohanty, 2004). Compared with destruction methods which result in loss of significant amounts of VOCs, recovery and suppression methods seem to be more profitable options for collecting VOCs (Tamaddoni et al, 2014).…”

“…Compared with destruction methods which result in loss of significant amounts of VOCs, recovery and suppression methods seem to be more profitable options for collecting VOCs (Tamaddoni et al, 2014). These methods would be utilised for designing specific CVE control systems if their performance and stabilities were to be satisfactory (Gautam and Mohanty, 2004). There are several control methods (adapted from recovery procedures) for CVEs in inland and offshore transportations including absorption in crude oil, refrigeration/pressurisation condensation (to reuse as fuel), HC blanketing/recovering and vapour balancing (Table 1).…”

The effect of agitation on volatilization of naphthalene from solution containing surfactant

“…Toxic volatile emissions should be kept at minimal because of their potential fire hazard, and threat to workplace health and safety. With this regard, surfactants or foams have been used to suppress volatile emissions [35,36]. In other cases such as air stripping processes for the treatment of surfactant-laden soil washing/flushing waste streams, the presence of surfactants is troublesome in an effort to maximize the VOCs removal [24,33,37].…”