Research on the Differences of the Pore Characteristics with Different Destroyed-Type Coals

Abstract

In order to investigate the pore characteristics of the different destroyed-types of coals and its effects of coal and gas outburst, this article studyed the low temperature nitrogen adsorption curve, specific surface area, pore volume and its distribution with the method of low-temperature nitrogen adsorption, also studed their changes with the different destroyed-type of coals, and the influences of pore shape and distribution for coal and gas outburst. The results showed that three different destroyed-types of coals have loops, the pore shapes of the coals mainly open-shaped, maybe also contain the flask-shaped. The raw coal has more open-shaped pores, fragmentated coal contains a large number of micropore, the crushed coal richs micropore and mesopore. The crushed coal in the large aperture of the medium relative pressure range mainly has open-shaped pore, then in maller pore size range of low relative pressure mainly has closed pore. With the increasing of destroyed-degree, the porosity increased, the anti-destruction capability reduced, the coal is more easily broken, then the risk of outburst is greater.

Bituminous Coal Sorption Characteristics and Its Modeling of the Main Coal Seam Gas Component in the Huaibei Coalfield, China

“…CBM is stored primarily in coal through adsorption onto the coal surface; thus, it is the pore surface area of the coal that determines the maximum gas holding potential of a reservoir [2]. As a natural porous media, coal usually has an incredibly complex pore structure, including many micropores, cleats, and fissures, and the specific surface area of coal generally reaches 6~15 m 2 /g [3][4][5][6]. As a result, coal shows a strong adsorption capacity to some gases and the adsorption gas accounts for more than 90% of the gas storage within the coal [7].…”

The binary gas sorption in the bituminous coal of the Huaibei Coalfield in China

“…Natural porous media usually have an extremely complex pore structure with pore sizes that may extend over several orders of magnitude (Cai et al., 2012). As coal has many micropores, cleats, and fissures, the specific surface area of coal is generally 6–15 m 2 /g (Chen et al., 2013; Qi et al., 2013). As a consequence, coal exhibits a strong adsorption capacity for several gases (Yang et al., 2015) and adsorption gas accounts for more than 90% of the gas stored within the coal (Mastalerz et al., 2004).…”