Effects of oxygen supply on low-temperature oxidation of coal: A case study of Jurassic coal in Yima, China

Su, Haijun; Zhou, Fang; Li, Jinshi; Han, Qing

doi:10.1016/j.fuel.2017.04.055

Cited by 74 publications

(27 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, in this case, the heating of coal up to * 100/113°C improved the transport capacity of the oxygen in the pores and the reaction of O 2 with active sites on the pore surfaces occurred. The works of Meng et al (2016), Su et al (2017) and Shi et al (2018) reveals that with increase of coal temperature, consumption of oxygen grew slowly at first at temperatures up to 70°C while O 2 chemisorption dominated, then, at temperatures above 80°C, it grew rapidly as O 2 reaction with active sites dominated. The actual oxygen reaction took place on the active centers of the coal structure, namely on the aliphatic and alicyclic groups associated with the aromatic rings, to form unstable peroxides and hydroperoxides (Kurková 2002); from these unstable intermediates then stable oxygen compounds with CO and COO groups are formed; and finally, retrograde humic acids are formed (Klika and Kraussová 1993;Klika 1999;Kurková 2002).…”

Section: Temperature Of Coal Alteration As Estimated From Micropetrogmentioning

confidence: 97%

Coalification and coal alteration under mild thermal conditions

Straka

Sýkorová

2018

Int J Coal Sci Technol

View full text Add to dashboard Cite

Coalification temperatures are often considered to be approximately 100-170°C for bituminous coal and 170-275°C for anthracite. However, our micropetrographic observations, solid state 27 Al magic-angle spinning nuclear magnetic resonance measurements, interpretation of d 13 C values for whewellite in pelosiderite concretions from Carboniferous sediments, and assessment of whewellite thermal stability show that coalification temperatures can be significantly lower. Also the temperatures of coal alteration may be substantially lower than is stated. Ordinarily, hightemperature alteration is reported, but microthermometric measurements of fluids temperatures and micropetrographic observations show that the coal alteration can take place at low temperatures. For this reason, coals from the Kladno-Rakovník Basin, part of Late Paleozoic continental basins of the Czech Republic, were analyzed. Regarding coalification, micropetrographic characterizations of unaltered coals, the presence of thermally unstable Al complexes in the coal organic mass documented using 27 Al MAS NMR method, and proven occurrence of whewellite in pelosiderite concretions suggest a lower coalification temperature, max.~70°C. Regarding coal alteration, micropetrographic observations revealed (a) the weaker intensity of fluorescence of liptinite, (b) mylonitic structures and microbreccia with carbonate fluid penetration, and (c) high oxygen content in coals (37-38 wt.%). These phenomena are typical for thermal and oxidative alteration of coal. As the temperature of carbonate fluids inferred from fluid inclusion analysis was evaluated as * 100-113°C, the temperature of coal alteration was suggested as * 113°C; the alteration was caused by hot hydrothermal fluids.

show abstract

Section: Temperature Of Coal Alteration As Estimated From Micropetrogmentioning

confidence: 97%

Coalification and coal alteration under mild thermal conditions

Straka

Sýkorová

2018

Int J Coal Sci Technol

View full text Add to dashboard Cite

show abstract

“…In field practice, the index of the gas concentration ratio is usually selected for analysis to eliminate the influence of the air flow rate on concentration [27]. Similar to previous research results, the relationships temperature-time, CO-temperature, CO/CO2-temperature, C2H4/C2H6-temperature and C3H8/C2H6-temperature were selected for analysis in this paper [28,29]. The programmed heating experiments were conducted for coal, oil shale, and mixed coal and oil shale with a coal to oil shale ratio of 1:0.22 (that is the ratio of coal to oil shale in the goaf in the field experiments) to study the variations of the behaviors of temperature and gas concentration during programmed heating.…”

Section: Analysis Of the Experimental Resultsmentioning

confidence: 99%

“…In field practice, the index of the gas concentration ratio is usually selected for analysis to eliminate the influence of the air flow rate on concentration [27]. Similar to previous research results, the relationships temperature-time, CO-temperature, CO/CO 2 -temperature, C 2 H 4 /C 2 H 6 -temperature and C 3 H 8 /C 2 H 6 -temperature were selected for analysis in this paper [28,29]. As shown in Figure 2, the sample temperature changed with time in the programmed heating experiment.…”

Section: Analysis Of the Experimental Resultsmentioning

confidence: 99%

Study on the Low-Temperature Oxidation Law in the Co-Mining Face of Coal and Oil Shale in a Goaf—A Case Study in the Liangjia Coal Mine, China

Wang

Sun

et al. 2018

Energies

View full text Add to dashboard Cite

Abstract:The low-temperature oxidation law of coal and rock mass is the basis to study spontaneous combustion in goafs. In this paper, the low-temperature oxidation laws of coal, oil shale, and mixtures of coal and oil shale were studied by using laboratory programmed heating experiments combined with a field beam tube monitoring system. The results from the programmed heating experiments showed that the heat released from oil shale was less than that from coal. Coal had a lower carbon monoxide (CO)-producing temperature than oil shale, and the mixture showed obvious inhibiting effects on CO production with an average CO concentration of about 38% of that for coal. Index gases were selected in different stages to determine the critical turning point temperature for each stage. The field beam tube monitoring system showed that the temperature field of the 1105 co-mining face of coal and oil shale in the goaf of the Liangjia Coal Mine presented a ladder-like distribution, and CO concentration was the highest for coal and lower for the mixture of coal and oil shale, indicating that the mixture of coal with oil shale had an inhibiting effect on CO production, consistent with the results from the programmed heating experiments.

show abstract

“…Low concentrations of nitrogen, carbon dioxide, and methane were measured in the route (parameters nos. [8][9][10], and a concentration of nitrogen was measured behind the dam at a distance of 350 m (parameter no. 30).…”

Section: Resultsmentioning

confidence: 99%

“…The coal and oxygen reaction results from the release of heat as well as the emission of gaseous products, typically carbon monoxide, carbon dioxide, hydrogen, as well as saturated and unsaturated hydrocarbons. There are several papers published which discuss the monitoring of gases emitted from the source of coal heating [9][10][11][12][13][14]. In the course of the said studies, it was mainly observed that the concentration of the gases increases with the temperature increase, which was applied to determine the degree of fire hazard in coal mines.…”

Section: Introductionmentioning

confidence: 99%

Study of the Hazard of Endogenous Fires in Coal Mines—A Chemometric Approach

Wojtacha‐Rychter

Smoliński

2018

Energies

View full text Add to dashboard Cite

The most commonly used practice to assess fire hazard development in underground coal mines is based on the measurement of the concentration of selected gases in the mine's air. The main goal of this study was present a strategy to monitor the gaseous atmosphere in the mine in order to identify the onset of an endogenous fire in the coal seam. For that purpose, the principal component analysis (PCA) and the hierarchical clustering analysis (HCA) were applied. The monitoring covers the measurements of concentration of CO, CO 2 , H 2 , O 2 , N 2 , and selected hydrocarbons, respectively throughout the whole of one year. The chemometric methods applied allow for effective exploration of the similarities between the studied samples collected both under fire hazard conditions and under safe conditions. Based on the constructed models, the groups of objects characterized with the highest content of ethylene, acetylene, propylene, and carbon monoxide were identified. These samples indicate the endogenic fire in coal mine.

show abstract

Effects of oxygen supply on low-temperature oxidation of coal: A case study of Jurassic coal in Yima, China

Cited by 74 publications

References 24 publications

Coalification and coal alteration under mild thermal conditions

Coalification and coal alteration under mild thermal conditions

Study on the Low-Temperature Oxidation Law in the Co-Mining Face of Coal and Oil Shale in a Goaf—A Case Study in the Liangjia Coal Mine, China

Study of the Hazard of Endogenous Fires in Coal Mines—A Chemometric Approach

Contact Info

Product

Resources

About