Observation of trapped gas during electrical resistance heating of trichloroethylene under passive venting conditions

Gas production and transport during bench-scale electrical resistance heating of water and trichloroethene

“…Martin and Kueper (2011) further exemplified this in the presence of low-permeability layers, where the absence of steam conduits resulted in local accumulation and lateral migration of co-boiled vapor leading to reduced mass removal. There is a need to understand the gas saturations at which connected pathways can be created during ISTT, and how parameters monitored during ERH, such as temperature or electric current (USACE, 2009), can be affected by gas production and transport mechanisms.…”

“…When gas is first formed, P c is characteristic of the nucleation mechanism (Atchley and Prosperetti, 1989;Carey, 2007;Satik and Yortsos, 1996). Vaporization at the interface of an immiscible liquid pair, such as groundwater and DNAPL, occurs at the co-boiling (i.e., steam distillation) point, which is lower than the boiling point of each liquid phase because the vapor pressures of immiscible liquids are additive at their interface (e.g., Martin and Kueper, 2011;Triplett Kingston et al, 2014;Zhao et al, 2014). For example, the co-boiling temperature of TCE and water is 73°C at atmospheric pressure (USACE, 2009).…”

“…Increased hydrostatic pressure causes the boiling or co-boiling points to increase with depth below the water table, as higher temperatures are required to increase the vapor pressure. Co-boiling plateaus have been observed in laboratory studies when thermocouples are in the vicinity of the DNAPL-water interface in single-component systems (e.g., Burghardt and Kueper, 2008;Martin and Kueper, 2011;Udell, 1998;Zhao et al, 2014), but both the detection and observed length of a co-boiling plateau are sensitive to the proximity of the thermocouple location to the DNAPL-water interface (Zhao et al, 2014). Following nucleation, the continued growth and coalescence of gas during heating lead to internal drainage.…”

“…Previous studies have highlighted the importance of establishing connected gas channels for advective transport between the DNAPL source zone and extraction points (e.g., Heron et al, 1998;Martin and Kueper, 2011) and that subsurface temperatures should be increased to the boiling point of groundwater to facilitate the formation of steam conduits (e.g., Baker and Hiester, 2009;Heron et al, 2006). Martin and Kueper (2011) further exemplified this in the presence of low-permeability layers, where the absence of steam conduits resulted in local accumulation and lateral migration of co-boiled vapor leading to reduced mass removal.…”

Steam-Enhanced Extraction Experiments, Simulations and Field Studies for Dense Non-Aqueous Phase Liquid Removal: A Review

“…The results reverses the multiphase flow code predictions which state that pressure will increase when heating low permeable material, leading to overturn the boiling. The trapped gas behavior under passive venting conditions was investigate by Martin and Kueper [29] during application of electrical resistance heating in removal of TCE. The results show the influence of gas phase venting during remediation process of electrical resistance heating.…”