Changes in pore structure of coal caused by coal-to-gas bioconversion

Rui Zhang, Shimin Liu, Jitendra Bahadur, Derek Elsworth, Yi Wang, Guanglong Hu, Yanna Liang

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Microbial enhanced coalbed methane (ME-CBM) recovery is critically examined as a viable technology for natural gas recovery from coalbed methane (CBM) reservoirs. Since the majority of gas-in-place (GIP) is stored as an adsorbed phase in fine pores of coal matrix, the nano-pore structure directly influences gas storage and transport properties. Only limited studies have quantified the alteration of the nano-pore structure due to ME-CBM treatment. This study examines the evolution of the pore structure using a combination of small angle X-ray scattering (SAXS), low-pressure N2 and CO2 adsorption (LPGA) and high-pressure methane adsorption methods. The results show that the surface fractal dimension decreases for the two bioconverted coals compared to the untreated coal. After bio-treatment, the mesopore surface area and pore volume decrease with the average pore diameter increases, while the micropore surface area increases with pore volume decreases. Both inaccessible meso-/micropore size distributions decrease after bioconversion, while the accessible micropore size distribution increases, making a portion of closed micropore network accessible. In addition, the methane adsorption capacities increase after bio-treatment, which is confirmed by the increase of micropore surface area. A conceptual physical model of methanogenesis is proposed based on the evolution of the pore structure.

Original languageEnglish (US)
Article number3840
JournalScientific reports
Volume7
Issue number1
DOIs
StatePublished - Dec 1 2017

Fingerprint

Coal
Methane
Gases
Adsorption
Natural Gas
Pressure
Fractals
X-Rays
Technology

All Science Journal Classification (ASJC) codes

  • General

Cite this

Zhang, Rui ; Liu, Shimin ; Bahadur, Jitendra ; Elsworth, Derek ; Wang, Yi ; Hu, Guanglong ; Liang, Yanna. / Changes in pore structure of coal caused by coal-to-gas bioconversion. In: Scientific reports. 2017 ; Vol. 7, No. 1.
@article{a946254f683e402086778fb4673cd247,
title = "Changes in pore structure of coal caused by coal-to-gas bioconversion",
abstract = "Microbial enhanced coalbed methane (ME-CBM) recovery is critically examined as a viable technology for natural gas recovery from coalbed methane (CBM) reservoirs. Since the majority of gas-in-place (GIP) is stored as an adsorbed phase in fine pores of coal matrix, the nano-pore structure directly influences gas storage and transport properties. Only limited studies have quantified the alteration of the nano-pore structure due to ME-CBM treatment. This study examines the evolution of the pore structure using a combination of small angle X-ray scattering (SAXS), low-pressure N2 and CO2 adsorption (LPGA) and high-pressure methane adsorption methods. The results show that the surface fractal dimension decreases for the two bioconverted coals compared to the untreated coal. After bio-treatment, the mesopore surface area and pore volume decrease with the average pore diameter increases, while the micropore surface area increases with pore volume decreases. Both inaccessible meso-/micropore size distributions decrease after bioconversion, while the accessible micropore size distribution increases, making a portion of closed micropore network accessible. In addition, the methane adsorption capacities increase after bio-treatment, which is confirmed by the increase of micropore surface area. A conceptual physical model of methanogenesis is proposed based on the evolution of the pore structure.",
author = "Rui Zhang and Shimin Liu and Jitendra Bahadur and Derek Elsworth and Yi Wang and Guanglong Hu and Yanna Liang",
year = "2017",
month = "12",
day = "1",
doi = "10.1038/s41598-017-04110-z",
language = "English (US)",
volume = "7",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",
number = "1",

}

Changes in pore structure of coal caused by coal-to-gas bioconversion. / Zhang, Rui; Liu, Shimin; Bahadur, Jitendra; Elsworth, Derek; Wang, Yi; Hu, Guanglong; Liang, Yanna.

In: Scientific reports, Vol. 7, No. 1, 3840, 01.12.2017.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Changes in pore structure of coal caused by coal-to-gas bioconversion

AU - Zhang, Rui

AU - Liu, Shimin

AU - Bahadur, Jitendra

AU - Elsworth, Derek

AU - Wang, Yi

AU - Hu, Guanglong

AU - Liang, Yanna

PY - 2017/12/1

Y1 - 2017/12/1

N2 - Microbial enhanced coalbed methane (ME-CBM) recovery is critically examined as a viable technology for natural gas recovery from coalbed methane (CBM) reservoirs. Since the majority of gas-in-place (GIP) is stored as an adsorbed phase in fine pores of coal matrix, the nano-pore structure directly influences gas storage and transport properties. Only limited studies have quantified the alteration of the nano-pore structure due to ME-CBM treatment. This study examines the evolution of the pore structure using a combination of small angle X-ray scattering (SAXS), low-pressure N2 and CO2 adsorption (LPGA) and high-pressure methane adsorption methods. The results show that the surface fractal dimension decreases for the two bioconverted coals compared to the untreated coal. After bio-treatment, the mesopore surface area and pore volume decrease with the average pore diameter increases, while the micropore surface area increases with pore volume decreases. Both inaccessible meso-/micropore size distributions decrease after bioconversion, while the accessible micropore size distribution increases, making a portion of closed micropore network accessible. In addition, the methane adsorption capacities increase after bio-treatment, which is confirmed by the increase of micropore surface area. A conceptual physical model of methanogenesis is proposed based on the evolution of the pore structure.

AB - Microbial enhanced coalbed methane (ME-CBM) recovery is critically examined as a viable technology for natural gas recovery from coalbed methane (CBM) reservoirs. Since the majority of gas-in-place (GIP) is stored as an adsorbed phase in fine pores of coal matrix, the nano-pore structure directly influences gas storage and transport properties. Only limited studies have quantified the alteration of the nano-pore structure due to ME-CBM treatment. This study examines the evolution of the pore structure using a combination of small angle X-ray scattering (SAXS), low-pressure N2 and CO2 adsorption (LPGA) and high-pressure methane adsorption methods. The results show that the surface fractal dimension decreases for the two bioconverted coals compared to the untreated coal. After bio-treatment, the mesopore surface area and pore volume decrease with the average pore diameter increases, while the micropore surface area increases with pore volume decreases. Both inaccessible meso-/micropore size distributions decrease after bioconversion, while the accessible micropore size distribution increases, making a portion of closed micropore network accessible. In addition, the methane adsorption capacities increase after bio-treatment, which is confirmed by the increase of micropore surface area. A conceptual physical model of methanogenesis is proposed based on the evolution of the pore structure.

UR - http://www.scopus.com/inward/record.url?scp=85021053067&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85021053067&partnerID=8YFLogxK

U2 - 10.1038/s41598-017-04110-z

DO - 10.1038/s41598-017-04110-z

M3 - Article

C2 - 28630465

AN - SCOPUS:85021053067

VL - 7

JO - Scientific Reports

JF - Scientific Reports

SN - 2045-2322

IS - 1

M1 - 3840

ER -