Experimental supercritical CO2 and water interactions with Carboniferous coal, Germany

Dawson, Grant Kristofor Wayne, Golding, Suzanne D., Bae, Jun-Seok, Biddle, Dean and Massarotto, Paul (2009). Experimental supercritical CO2 and water interactions with Carboniferous coal, Germany. In: Goldschmidt 2009 - "Challenges to our volatile planet". 19th Annual V.M. Goldschmidt Conference, Davos, Switzerland, (A268-A268). 21-26 June 2009.

Author Dawson, Grant Kristofor Wayne
Golding, Suzanne D.
Bae, Jun-Seok
Biddle, Dean
Massarotto, Paul
Title of paper Experimental supercritical CO2 and water interactions with Carboniferous coal, Germany
Formatted title
Experimental supercritical CO2 and water interactions with Carboniferous coal, Germany
Conference name 19th Annual V.M. Goldschmidt Conference
Conference location Davos, Switzerland
Conference dates 21-26 June 2009
Proceedings title Goldschmidt 2009 - "Challenges to our volatile planet"   Check publisher's open access policy
Journal name Geochimica et Cosmochimica Acta   Check publisher's open access policy
Place of Publication Oxford, United Kingdom
Publisher Pergamon
Publication Year 2009
Sub-type Published abstract
ISSN 0016-7037
Volume 73
Issue 13 Suppl. 1
Start page A268
End page A268
Total pages 1
Language eng
Formatted Abstract/Summary
The three main options for geological storage of CO2 are depleted oil and gas fields, coal seams and deep saline formations. CO2 is stored in coal mainly as adsorbed molecules on micropore surfaces that allow higher densities at same depths than in conventional oil and gas reservoirs and saline formations. Injected CO2 will also dissolve in formation water and the resulting acid will react with minerals in the coal seam (solution and mineral trapping) which further reduces the risk of CO2 leakage. In the current study we simulated CO2 injection into deep coal seams using batch experiments conducted at 40°C and 90 bar for 72 hrs, to evaluate physical and chemical changes caused by exposure of coal to a mixture of water and supercritical CO2. Within a purpose built batch reactor, two sister coal cubes (15 mm to a side) were separately immersed in a mixture of supercritical CO2 and RO water (SCO2-H2O), and a third sister cube was immersed in RO water (H2O) only. The Carboniferous coal analysed was thinly interbanded, with a vitrinite reflectance of 0.93%. The three sister cubes were cut immediately adjacent to each other from the same horizontal interval of a larger coal block, sourced from an underground coal mine in Germany. The leachate chemistry from the SCO2-H2O experiments indicates significant mobilisation of metals which we attribuite to dissolution of cleat and matrix mineral matter and displacement of cation exchangeable metals from the coal. Visible quantities of fine particles were also produced by the experiments. Coal density is much less affected by exposure to H2O alone and little mineral matter is mobilised compared with the SCO2-H2O experiments. SEM images also provide evidence of dissolution/alteration of cleat and matrix minerals. Demineralisation reactions with SCO2-H2O are evident from sample weight loss (after accounting for fines produced) and an increase in LP CO2 adsorption (as shown from experiments with coal powders). Thus, any reduction in permeability due to CO2 induced coal swelling may be at least partly countered by dissolution and mobilisation of mineral matter in the coal seam near the injection well.
Subjects 970104 Expanding Knowledge in the Earth Sciences
040309 Petroleum and Coal Geology
Q-Index Code CX
Q-Index Status Provisional Code
Institutional Status UQ
Additional Notes Special issue: Awards Ceremony Speeches and Abstracts of the 19th Annual V.M. Goldschmidt Conference, V.M. Goldschmidt Conference

Document type: Conference Paper
Collection: School of Earth Sciences Publications
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Created: Wed, 05 May 2010, 14:12:31 EST by Tracy Paroz on behalf of School of Earth Sciences