Effect of Pretreatment with Carbonic Acid on “HyperCoal” (Ash-Free Coal) Production from Low-Rank Coals
2005; American Chemical Society; Volume: 19; Issue: 5 Linguagem: Inglês
10.1021/ef050030t
ISSN1520-5029
AutoresKensuke Masaki, Nao Kashimura, Toshimasa Takanohashi, Shinya Sato, Akimitsu Matsumura, Ikuo Saito,
Tópico(s)Coal and Coke Industries Research
ResumoThe use of "HyperCoal" (ash-free coal) as feedstock for gas turbines results in higher net power output with lower CO2 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 (CO2 dissolved in water−CO2/H2O) produced a strong increase in HyperCoal yields at relatively lower CO2 pressures of 0.1−0.5 MPa; the thermal extraction yields at 360 °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 °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.
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