Pore volume and surface area of the Carboniferous coals from the Zonguldak basin (NW Turkey) and their variations with rank and maceral composition

Gürdal, Gülbin; Yalçın, Mehmet

doi:10.1016/s0166-5162(01)00051-9

Cited by 138 publications

(65 citation statements)

References 18 publications

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“…The characteristics of pore structures in coal are related to many factors, including the coal's degree of metamorphism (Bustin and Clarkson 1998;Prinz et al 2004;Prinz and Littke 2005;Tang et al 2008;Zhou and Wu 2012;Ding et al 2011;Gürdal and Yalçın 2001), degree of deformation Ogawa 2001, 2003;Jiang et al 2011;Xue et al 2012;Qu and Wang 2010), macerals (Zhou and Wu 2012;Gürdal and Yalçın 2001;Cai et al 2011;Mastalerz et al 2008), and minerals (Zhou and Wu 2012). Many scholars have conducted a tremendous amount of research in this aspect.…”

Section: Introductionmentioning

confidence: 99%

“…Many scholars have conducted a tremendous amount of research in this aspect. Among them, most are about the effects of metamorphism on the pore system of coal (Bustin and Clarkson 1998;Prinz et al 2004;Prinz and Littke 2005;Tang et al 2008;Zhou and Wu 2012;Ding et al 2011;Gürdal and Yalçın 2001). CO 2 isothermal adsorption experiments conducted by Bustin and Clarkson (1998) showed that as coal rank increased, the volume and surface area of micropores (<2 nm) in coal samples decreased initially and then increased and reached the minimum at the bituminous coal stage.…”

Section: Introductionmentioning

confidence: 99%

“…There is also much research on the effect of macerals on pore characteristics. Some scholars believe that there is a positive correlation between high vitrinite content and the contents of micropores (<10 nm) and small pores (10-100 nm) (Zhou and Wu 2012;Cai et al 2011), while others believe that this correlation is not obvious (Gürdal and Yalçın 2001;Mastalerz et al 2008). Mineral filling is an important factor that influences the contents of macropores (>1,000 nm) and mesopores (100-1,000 nm) in coal reservoirs (Zhou and Wu 2012).…”

Section: Introductionmentioning

confidence: 99%

“…Many scholars have used mercury intrusion porosimetry, liquid nitrogen and small-angle neutron scattering to study coal pore structures and its influence factors, and they have also carried out significant discussions on the impact on CH 4 adsorption capacity (Bustin and Clarkson 1998;Prinz et al 2004;Prinz and Littke 2005;Tang et al 2008;Zhou and Wu 2012;Ding et al 2011;Gürdal and Yalçın 2001;Ogawa 2001, 2003;Jiang et al 2011;Xue et al 2012;Qu and Wang 2010;Cai et al 2011;Mastalerz et al 2008;Pan et al 2012;Sakurovs et al 2012;Feng et al 2013;Cai et al 2013;Zhang et al 2012). However, we find that the studies on tectonically deformed coal are not fully addressed, particularly in nanoscale pore level.…”

Section: Introductionmentioning

confidence: 99%

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Nanoscale Pores in Coal Related to Coal Rank and Deformation Structures

et al. 2015

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Experimental results show that nanoscale pores in coal are affected by coal rank and deformation structures. In terms of pore volume, the transitional pores occupy the largest proportion, and in terms of specific surface area, the sub-micropores take up the largest proportion. For weak brittle deformed coal (including normal structured coal), when the coal rank increases, the volume and specific surface area of pores in different sizes firstly decrease and then increase. The volume and specific surface area of transitional pores and micropores in coal reach the minimum at about R O,ran = 2.0 %. After that, a slow increasing trend is observed. The volume of sub-micropores reaches the minimum at about R O,ran = 1.5 % and then shows a trend of rapid growth as coal rank increases. As the degree of coal deformation increases, both pore volume and specific surface area have a significant increase. Under strong tectonic deformation, both the volume and total specific surface area of the nanoscale pores and of sub-micropores increase significantly; the volume of transitional pores increases moderately, and their specific surface area shows a decreasing trend; the volume and specific surface area increments of micropores decline rapidly as the degree of metamorphism increases.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Nanoscale Pores in Coal Related to Coal Rank and Deformation Structures

et al. 2015

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“…32 It is assumed that the pore system of rock material is composed of different capillaries with different sizes, and the entire pore volume is divided into several intervals with the same volume. The interval permeability is calculated, and then the entire permeability is obtained by adding the interval permeability together in statistical view.…”

Section: Permeabilitymentioning

confidence: 99%

Multi-scale characteristics of coal structure by x-ray computed tomography (x-ray CT), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP)

2018

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It is of great benefit to study the material and structural heterogeneity of coal for better understanding the coalbed methane (CBM) storage and enrichment. In this paper, multi-scale X-ray computed tomography (CT), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP) at multi scales were conducted to thoroughly study the material distribution, heterogeneity, pore development, porosity and permeability of coal. It is suitable and reasonable to divide the testing samples into three structural categories by average density and heterogeneity degree, and the meso structure in the three categories accords with the morphology on SEM images. The pore size distribution and pore development of each subsample cannot be correspondingly related to their respective structure category or morphology due to different observation scales, while the macro pore size development, accumulated macro pore volume and macro pores porosity accord with the meso structure category and morphology information by CT and SEM at the same scale very well. Given the effect of macro pores on permeability and the contribution of micro pores to CBM storage capacity, reservoirs with developed micro pores and macro pores may be the most suitable coal reservoir for CBM exploitation.

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Enhanced Coal Bed Methane Recovery: Using Injection of Nitrogen and Carbon Dioxide Mixture

Perera

Ranjith

2015

Handbook of Clean Energy Systems

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Conventionally, coal bed methane ( CBM ) is produced by pumping out naturally existing pore fluid (water). However, this takes extensive time, does not produce commercially viable amounts of CBM , and is associated with many environmental hazards. Therefore, it is necessary to find new technologies to recover CBM in a safer and more economical way. The process of injecting a gas or a mixture of gases into a coal seam to enhance methane recovery is called enhanced coal bed methane ( ECBM ) recovery , and CO 2 ‐ECBM and N 2 ‐ECBM are the main techniques currently used. In the CO 2 ‐ECBM process, methane is desorbed from the seam by injecting more reactive CO 2 into the coal seam and, if performed properly, will also result in long‐term sequestration of CO 2 . However, CO 2 ‐adsorption‐induced swelling in coal causes reduced fracture pore space and gas flow through the coal seam; two disadvantages that have negatively affected field CO 2 ‐ECBM projects (cf. the Allison project in the San Juan Basin). In the N 2 ‐ECBM process, injecting N 2 first displaces free CH 4 from the seam, creating a zero methane partial pressure, which eventually causes the adsorbed phase CH 4 to be released. The rapid N 2 breakthrough in producing methane is the major issue experienced in present N 2 ‐ECBM field projects (see the Tiffany unit in the San Juan Basin). Therefore, to find the optimum technique for the ECBM process, the merits and demerits of the two processes need to be compared in relation to productivity, environmental impact, and economical aspects. In relation to productivity, although the N 2 ‐ECBM process creates a quicker and higher CBM recovery, it also involves earlier N 2 breakthroughs compared to the CO 2 ‐ECBM process. Regarding the environmental impact, leakage of CO 2 from the reservoir during the CO 2 ‐ECBM process creates local hazards for humans, ecosystems, and groundwater, and global hazards such as climate change. Such hazards are minimal with the N 2 ‐ECBM process because of the inert nature of N 2 . However, the CO 2 ‐ECBM process also assists in protecting the environment by contributing to the mitigation of the atmospheric CO 2 level by the geological sequestration of CO 2 . If the economic aspect is considered, although the N 2 ‐ECBM process involves higher processing cost, it is more economically viable because of the lower quantity of N 2 required for the process, which is around 0.5 ft 3 of N 2 to displace 1 ft 3 of methane from the seam, compared to 2–3 ft 3 of CO 2 for the CO 2 ‐ECBM process. However, the considerable contribution to the reduction of atmospheric CO 2 levels of the CO 2 ‐ECBM process cannot be ignored. The injection of a mixture of CO 2 and N 2 is believed to create a better production mechanism, and according to field projects (cf. the Fenn Big Valley basin in Alberta, Canada), the N 2 + CO 2– ECBM process offers a higher production rate with early response, and sequestrates a similar amount of CO 2 to the CO 2 ‐ECBM process. Furthermore, the use of the mixture reduces problems associated with CO 2 injection‐induced coal swelling and early breakthrough with N 2 injection. However, finding the optimum N 2 + CO 2 gas mixture to recover a maximum amount of methane from a coal seam while sequestrating an optimum amount of CO 2 is a challenge due to the rank dependency of coal. To date, there is a lack of ECBM applications worldwide because of geological, economic, and policy barriers. In relation to the geological barriers, no ECBM project will be economical if there is not a commercially viable amount of gas in the coal seam or the available gas is difficult to harvest because of the geological condition of the reservoir. The large capital cost associated with drilling, exploration, production, and field‐scale testing with limited return on investment is the main economic barrier and has resulted in less investment. Moreover, the current lack of penalties for CO 2 emissions and the strict environmental rules for safe coal mining have also had negative effects. Most importantly, the ECBM technique is still in its infancy because of lack of knowledge of the process due to the complex hydro‐chemical–mechanical behavior of coal during the injection process.

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Pore volume and surface area of the Carboniferous coals from the Zonguldak basin (NW Turkey) and their variations with rank and maceral composition

Cited by 138 publications

References 18 publications

Nanoscale Pores in Coal Related to Coal Rank and Deformation Structures

Nanoscale Pores in Coal Related to Coal Rank and Deformation Structures

Multi-scale characteristics of coal structure by x-ray computed tomography (x-ray CT), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP)

Enhanced Coal Bed Methane Recovery: Using Injection of Nitrogen and Carbon Dioxide Mixture

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