Effect of pretreatment with carbonic acid on 'Hypercoal' (ash-free coal) production from low-rank coals

Journal Article · Sat Oct 01 04:00:00 EDT 2005 · Energy and Fuels

DOI:https://doi.org/10.1021/ef050030t· OSTI ID:20674544

Masaki, Kensuke; Kashimura, Nao; Takanohashi, Toshimasa; Sato, Shinya; Matsumura, Akimitsu; Saito, Ikuo ^[1]

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1. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan). Energy Technology Research Institute

The use of 'HyperCoal' (ash-free coal) as feedstock for gas turbines results in higher net power output with lower CO{sub 2} emissions. HyperCoal can be produced by thermal extraction from low-rank coals with industrial organic solvents in an inert atmosphere, providing raw materials. The pretreatment of low-rank coals with carbonic acid (CO{sub 2} dissolved in water - CO{sub 2}/H{sub 2}O) produced a strong increase in HyperCoal yields at relatively lower CO{sub 2} pressures of 0.1-0.5 MPa; the thermal extraction yields at 360{sup o}C increased by 7%-15% with extraction yields of 52% and 45% obtained for Wyodak sub-bituminous coal and Beulah-Zap lignite, respectively. In the range of 320-360{sup o}C, crude methylnaphthalene oil (CMNO) extraction yields of pretreated Wyodak coal increased significantly (by 4%-11%) over those of raw coal. The enhanced extraction yields of these low-rank coals are attributed to disruption of cation-bridging crosslinks on acid pretreatment, and the release of the hydrogen bonds by CMNO extraction. 18 refs., 4 figs., 4 tabs.

• OSTI ID: 20674544
• Journal Information: Energy and Fuels, Journal Name: Energy and Fuels Journal Issue: 5 Vol. 19; ISSN ENFUEM; ISSN 0887-0624
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
CARBONIC ACID
LIGNITE
ORGANIC SOLVENTS
SOLVENT EXTRACTION
SOLVENT-REFINED COAL
SUBBITUMINOUS COAL
YIELDS