Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA

Abstract

Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires.

Health risk assessment of toxic VOCs species for the coal fire well drillers

“…Table 3 showed the comparison of toxic VOCs species emission from the coal fires (both in outcrop coal fire and underground coal fire) with other studies. In contrast with the outcrop coal fires of Ankney fire (Engle et al 2012), the concentrations of VOCs was much higher in Ankney fire than in the underground fire in this study, especially the level of benzene in Ankney fire was as much as 93.03 times in this study. Compared with other underground coal fires around the world, the concentration of six selected species from fires of Old Smokey, Witbank, and Sasolburg was far greater than from the underground fires in this study Pone et al 2007).…”

“…Compared with other underground coal fires around the world, the concentration of six selected species from fires of Old Smokey, Witbank, and Sasolburg was far greater than from the underground fires in this study Pone et al 2007). The concentrations of toluene discharged from Hotchkiss fire and Welch Ranch fire were about 286.36 times and 100.30 times more than this study, respectively, while the low level of benzene was found in those two coal fires (Engle et al 2012). Compared to other coal fires, East vent was the only one with coal fires which discharged lower level of toxic VOCs species than coal fires in this study (Hower et al 2009).…”

“…Previous researches about the pollutant exhaust from coal fires focus on gas compounds (e.g., SO 2 , NOx, Hg) emission both from outcrop coal fires and underground coal fires (Engle et al 2011;Engle et al 2012;Ide et al 2010). Few studies on the VOCs emissions of coal fires have been carried out.…”

“…Few studies on the VOCs emissions of coal fires have been carried out. Engle et al (2012) used the method of ground-based surveys of three coal fires and airborne surveys of two of the fires (including outcrop coal fires and underground coal fires) near Sheridan, Wyoming, and found that the fires produce locally dangerous levels of benzene. A research of VOCs analyses (including aromatic hydrocarbons, aliphatic hydrocarbon, and halogenated hydrocarbons) from Witbank and Sasolburg coalfields (underground coal seam fires) of South Africa was conducted by Pone et al(2007), and the results showed that relatively high concentrations of some toxic VOCs (e.g., toluene, benzene, xylene, and dichloromethane) were found in the gas collected at both coalfields.…”

Analysis of coal fire dynamics in the Wuda syncline impacted by fire-fighting activities based on in-situ observations and Landsat-8 remote sensing data

“…Furthermore, coal fires are a catastrophe occurring all around the world (Kuenzer and Stracher, 2012;Sinha and Singh, 2008;Stracher, 2004;Stracher and Taylor, 2004). Coal fires in China (Kuenzer et al, 2007bShao et al, 2014;Song and Kuenzer, 2014;Zhang et al, 2004a, India (Chatterjee, 2006;Gangopadhyay et al, 2012;Prakash and Gupta, 1999;Prakash et al, 1997), the USA (Engle et al, 2012b;Heffern and Coates, 2004;Hower et al, 2009;O'Keefe et al, 2010O'Keefe et al, , 2011, South Africa (Pone et al, 2008), and Australia (Ellyett and Fleming, 1974) have been reported in scientific literature.…”