Quasi-equilibrium swelling and structural parameters of coals

Effects of coal rank on physicochemical properties of coal and on methane adsorption

“…According to the structure and morphology of cell, Inertinite is divided into fusinite, half fusinite, fungus, secretion, coarse grain, particles, debris of inertinite, etc. Figure 10 shows the Chang et al 2006;Qin et al 2007;Chang et al 2008;Jiang et al 2012;Lin et al 2013;Xu and Pan 2015;Xiao et al 2016)-159, English Nelson et al 1980;Giuliani et al 1991;Crosdale et al 1998;Laxminarayana and Crosdale 2002;Busch et al 2003;Mastalerz et al 2004;Hildenbrand et al 2006;Busch et al 2006;Siemons et al 2007;Busch et al 2007;Faiz et al 2007a, b;Majewska and Ziętek 2007;Yu et al 2008a, b, c;Astashov et al 2008;Day et al 2008;Mazumder and Wolf 2008;Pone et al 2009;Majewska et al 2009;Radliński et al 2009;Battistutta et al 2010;Gensterblum et al 2010;He et al 2010;Kim et al 2011;Day et al 2011;Le Gal et al 2012;Maphala and Wagner 2012;Sakurovs 2012;An et al 2013;Cai et al 2013a, b;Dutka et al 2013)-292) relationship between inertinite and Vitrinite reflectance (R o;max ). Figure 10 shows that the relationship betw...…”

“…A small amount of carbon is present in carbonate and carbon dioxide, and the content of carbon in coal is higher than that in any other element. Therefore, the Chang et al 2006;Qin et al 2007;Faiz et al 2007a, b;Chang et al 2008;Jiang et al 2012;Lin et al 2013;Xiao et al 2016)-233, English Crosdale et al 1998;Laxminarayana and Crosdale 2002;Busch et al 2003;Mastalerz et al 2004;Busch et al 2006;Hildenbrand et al 2006;Busch et al 2007;Majewska and Ziętek 2007;Siemons et al 2007;Astashov et al 2008;Day et al 2008;Yu et al 2008a, b;Mazumder and Wolf 2008;Pone et al 2009;Radliński et al 2009;Majewska et al 2009;Gensterblum et al 2010;Battistutta et al 2010;He et al 2010;Day et al 2011;Kim et al 2011;Maphala and Wagner 2012;Sakurovs 2012;An et al 2013;Cai et al 2013a, b;Dutka et al 2013)-169) Effects of coal rank on physicochemical properties of coal and on methane adsorption 139 metamorphism degree of coal is often referred to as carbonization degree. In order to reduce the impact of ash, moisture and other content, we use ash-free basis Dry indicator, Fig.…”

Sorption and changes in bulk modulus of coal — experimental evidence and governing mechanisms for CBM and ECBM applications

“…To date, no explanations exist for the "remaining strain offset". We then took multiple swelling strain data sets for different samples reported in the literature (Astashov et al, 2008;Battistutta et al, 2010;Czaplinski, 1991, 1993;Cui et al, 2007;Day et al, 2008;Hol and Spiers, 2012), and quantified the magnitude of the "remaining strain offset". Only high pressure data (P f >6 MPa) by Hol and Spiers (2012), and Day et al (2008) were corrected for linear poroelastic effects.…”

3D mapping of carbon dioxide-induced strain in coal using digital volumetric speckle photography technique and X-ray computer tomography

“…Swelling and shrinkage of coal would result in the change of cleat aperture, which primarily determines the coal permeability. In order to evaluate the influence of swelling and shrinkage on the permeability, many laboratory experiments (Astashov et al, 2008;Chikatamarla et al, 2004;Durucan et al, 2009;Espinoza et al, 2014;Levine, 1996;Perera et al, 2013;Robertson and Christiansen, 2005;Wang et al, 2010) have been carried out, and various coal permeability models have also been proposed in an attempt to account for the effect of sorption-induced strain. Liu et al (2011) presented a review in which they classify the major models into two groups: permeability models under conditions of uniaxial strain and permeability models under conditions of variable stress.…”

“…Optical techniques were used to measure strain by Robertson and Christiansen (2005). Astashov et al (2008) used a laser method to measure sorption and simultaneously monitor swelling/shrinkage deformation based on the power modulation effect in a three-mirror optical resonator. Because coal structure is locally heterogeneous due to the presence of microstructural features like minerals matter, macerals, pores and cleats (Karacan, 2007), the local strain distribution during swelling/shrinkage is different from its macroscopic strain distribution.…”