Influence of coal composition and maturity on methane storage capacity of coals of Raniganj Coalfield, India

Mohanty, Debadutta; Chattaraj, Sujoy; Singh, Ajay Kumar

doi:10.1016/j.coal.2018.06.016

Cited by 25 publications

(9 citation statements)

References 33 publications

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“…It was in accordance with Zhang's results that the low-intensity aromatic -CH outof plane bands was observed in oxidized samples. 52 The content of alkanes rings [(CH)n, n > 4] increased by 37.69% after pretreatment, and continued to increase by 60.83% after 27 days of biodegradation. However, the content of alkanes rings during the biodegradation with raw coal only increased by 16.8%, suggesting that H 2 O 2 pretreatment promoted the formation of alkanes rings by microflora which might be a part of methanogenesis.…”

Section: The Changes In Functional Groups In Coal During H 2 O 2 Prmentioning

confidence: 99%

“…There were primarily six absorption bands detected in the infrared spectrum of aromatic structures (Figure 4, Table S1 in Online Resource), representing aromatic alkanes rings [(CH)n, n > 4], aromatics with 2 substitutions, aromatics with 3 substitutions, aromatics with 4 substitutions, and aromatics with 5 substitutions. The aromatic group in raw coal (RaC) mainly existed in the form of lower substitutions such as aromatics with 52 The content of alkanes rings [(CH)n, n > 4] increased by 37.69% after pretreatment, and continued to increase by 60.83% after 27 days of biodegradation. However, the content of alkanes rings during the biodegradation with raw coal only increased by 16.8%, suggesting that H 2 O 2 pretreatment promoted the formation of alkanes rings by microflora which might be a part of methanogenesis.…”

Section: The Changes In Functional Groups In Coal During H 2 O 2 Pretreatment Followed By Anaerobic Biodegradationmentioning

confidence: 99%

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Available methane from anthracite by combining coal seam microflora andH₂O₂pretreatment

et al. 2020

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Summary The conversion of coal to methane by anaerobic microorganisms is an efficient, clean, and green way to utilize coal. However, methane production is relatively low due to the low bioavailability of coal. H2O2 has been demonstrated to increase methane production by transferring coal to liquid organics. Little is known about the bioavailability of residual coal after H2O2 pretreatment. Here, H2O2 was employed to pretreat anthracite, and the potential of residual coal to produce methane was analyzed. The optimum conditions for pretreatment were 30% H2O2 for 12 hours when the methane production reached 254.97 μmol/g coal, increased by 24.98% compared with that in unpretreated coal. The results of FTIR showed that the substitutions of aromatics, alkanes rings, aliphatics, and even C=C structure in coal were depolymerized and oxygen‐containing functional groups were generated after pretreatment with H2O2. The oxygen‐containing functional groups were further degraded by anaerobic microflora. The XRD results showed that the crystal structure of coal decreased after pretreatment with H2O2 following 27 days of cultivation. These results suggested that H2O2 pretreatment mainly altered coal by increasing the oxygen‐containing functional groups and decreasing the crystal structure of coal to facilitate coal biodegradation and enhance biomethane production. The effect of H2O2 on the production of biomethane was not only to produce easily degradable organics, but also to change the coal structure and promote the degradation of residual coal. Therefore, the enhancement of biomethane production by H2O2 pretreatment on surface bioconversion and underground coalbed methane mining should take the increase methane yield from residual coal into account.

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Section: The Changes In Functional Groups In Coal During H 2 O 2 Prmentioning

confidence: 99%

Section: The Changes In Functional Groups In Coal During H 2 O 2 Pretreatment Followed By Anaerobic Biodegradationmentioning

confidence: 99%

Available methane from anthracite by combining coal seam microflora andH₂O₂pretreatment

et al. 2020

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“…As an important component of coalbed methane resources, biogenic coalbed methane has attracted increasing attention in recent years worldwide . As a type of macromolecular carbonaceous polymer with three‐dimensional structure, coal is mainly formed by intermolecular covalent bond and association interaction . The macromolecular structure model of coal shows that the coal macromolecules are polymerized from many basic structural units with similar and different structures and mainly consist of condensed aromatic rings, together with a small number of hydrogenated aromatic rings, alicyclic rings, and heterocycles.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4] As a type of macromolecular carbonaceous polymer with three-dimensional structure, coal is mainly formed by intermolecular covalent bond and association interaction. 5,6 The macromolecular structure model of coal shows that the coal macromolecules are polymerized from many basic structural units with similar and different structures and mainly consist of condensed aromatic rings, together with a small number of hydrogenated aromatic rings, alicyclic rings, and heterocycles. Its periphery is connected to alkyl side chain with less than three carbons and various functional groups.…”

Section: Introductionmentioning

confidence: 99%

Controlling mechanism of coal chemical structure on biological gas production characteristics

et al. 2020

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Summary To find the effect of coal chemical structure on biogas production, Lignite B was collected and extracted with nitrogen methylpyrrolidone (NMP), acetone and 0.60 mol/L NaOH. Simultaneously, methanogenic bacteria were enriched, and gas production experiments involving solvent extraction from residual coal and secondary gas production experiments involving coal were performed. The characteristics of biogas production, microcrystalline structure and coal chemical structure were analyzed. The results showed that the biogas production capacity of residual coal extracted by different solvents differed. The biogas production capacity of residual coal extracted by 0.60 mol/L NaOH was severely inhibited. The biogas production capacity of residual coal extracted by NMP and acetone was enhanced compared with that of raw coal. In contrast, primary residual coal still exhibits potential for methane production, but the methane production efficiency was reduced. Changes in the microcrystalline structure and functional groups of residual coal showed that solvent extraction increases the spacing and stacking height of the aromatic lamellae of coal, reduces the hydroxyl, methyl, methylene and aromatic hydrocarbon levels in coal, loosens the macromolecular network structure of coal, and enhances the connectivity of pores and fissures, thus allowing methane‐producing bacteria to enter the coal mass and create favorable conditions for gas production through interactions between the two. X‐ray photoelectron spectroscopy measurements showed that the secondary gas production increased the C content on the coal surface, decreased the O content and the O/C ratio, thus promoting the consumption of oxygen‐containing functional groups on the coal surface to further produce gas.

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“…Tectonization is an important factor in the formation of coal seams (Zhai et al., 2018). Coal methane adsorption capacity is influenced by pore structure (Hou et al., 2017), temperature (Pan et al., 2012), pressure, coal composition (Crosdale, 1998; Mohanty et al., 2018), chemical properties (Shan et al., 2018), etc. Meanwhile, ash, fixed carbon, moisture, vitrinite content, vitrinite reflectance, and temperature have also been previously selected as independent variables to predict V L (Langmuir volume) (Feng et al., 2014).…”

Section: Introductionmentioning

confidence: 99%

Impact of tectonic deformation on coal methane adsorption capacity

Jiang

Zhu

2019

Adsorption Science & Technology

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Tectonic deformation can cause significant changes in the physical and chemical structures of coal by damaging the macrostructure and macromolecular composition. For thorough research on the coal tectonic deformation impacts on gas adsorption capacity, this paper collected and summarized the parameters of experimental adsorption isotherms and coal macerals, conducted proximate and ultimate analyses, and systematically discussed the adsorption properties of different structures of coals and the influence of temperature and pressure on coal adsorption. Furthermore, the semi-quantitative relationships between the structural parameters of coal and its methane adsorption capacity are explored. The results show that (1) due to different tectonic stresses, the molecular and porous structures of different types of tectonic coal exhibit significant differences (e.g. sample N25, which is in a fault zone, has the highest methane adsorption capacity), and (2) coal methane adsorption capacity decreases along with increasing temperature. At a pressure of 12 MPa, primary coal (N32) showed Langmuir volume (VL) values of 15.38, 9.58, and 7.86 cm3/g and Langmuir pressure (PL) values of 3.82, 2.07, and 1.81 MPa at temperatures of 30°C, 50°C, and 70°C, respectively. (3) The Langmuir volume appears to have a linear relationship with parameters ID1/IG, Al/OX, and A-factor, as well as a parabolic curve relationship with fa, thereby illustrating that increases of apparent aromaticity can raise CH4 adsorption on coal.

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Influence of coal composition and maturity on methane storage capacity of coals of Raniganj Coalfield, India

Cited by 25 publications

References 33 publications

Available methane from anthracite by combining coal seam microflora andH₂O₂pretreatment

Available methane from anthracite by combining coal seam microflora andH₂O₂pretreatment

Controlling mechanism of coal chemical structure on biological gas production characteristics

Impact of tectonic deformation on coal methane adsorption capacity

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Influence of coal composition and maturity on methane storage capacity of coals of Raniganj Coalfield, India

Cited by 25 publications

References 33 publications

Available methane from anthracite by combining coal seam microflora andH2O2pretreatment

Available methane from anthracite by combining coal seam microflora andH2O2pretreatment

Controlling mechanism of coal chemical structure on biological gas production characteristics

Impact of tectonic deformation on coal methane adsorption capacity

Contact Info

Product

Resources

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Available methane from anthracite by combining coal seam microflora andH₂O₂pretreatment

Available methane from anthracite by combining coal seam microflora andH₂O₂pretreatment