Abstract
Two pairs of raw and acid-washed coal samples were prepared from Yallourn and Loy Yang brown coals, and subjected to rapid pyrolysis in a drop-tube reactor at 1073-1173 K in a stream of N2 or H2O/N2 mixture. Examinations were made on the roles of the inherent metallic species in the secondary reactions of nascent tar and char that were formed by the intraparticle primary reactions. The experimental results revealed that the inherent metallic species were essential for vary rapid steam reforming/gasification of the nascent tar/char and simultaneous suppression of soot formation. In the absence of the metallic species, the soot formation from the tar accounted as much as 15-19 and 6-13% of the carbon in coal in N2 and H2O/N2, respectively. The metallic species reduced the yield of soot to 6-8% in N2 by enhancing the reforming of tar by H2O generated from the pyrolysis of coal. In the H2O/N2 stream, instead of soot formation, a net gasification conversion up to 17% within 4.3 s was observed in the presence of the metallic species as a result of catalytic gasification of the nascent char. Moreover, the metallic species catalyzed the steam reforming of the nascent tar, giving its conversion up to 99%. Over the range of the conditions employed, a one-to-one stoichiometry was established between the steam consumption and the yield of carbon oxides formed by the steam reforming/gasification and water-gas-shift reaction.
| Original language | English |
|---|---|
| Pages (from-to) | 1977-1987 |
| Number of pages | 11 |
| Journal | Fuel |
| Volume | 81 |
| Issue number | 15 |
| DOIs | |
| Publication status | Published - Oct 1 2002 |
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All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Organic Chemistry
Cite this
Roles of inherent metallic species in secondary reactions of tar and char during rapid pyrolysis of brown coals in a drop-tube reactor. / Jun-Ichiro, Hayashi; Iwatsuki, Masahiro; Morishita, Kayoko; Tsutsumi, Atsushi; Li, Chun Zhu; Chiba, Tadatoshi.
In: Fuel, Vol. 81, No. 15, 01.10.2002, p. 1977-1987.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Roles of inherent metallic species in secondary reactions of tar and char during rapid pyrolysis of brown coals in a drop-tube reactor
AU - Jun-Ichiro, Hayashi
AU - Iwatsuki, Masahiro
AU - Morishita, Kayoko
AU - Tsutsumi, Atsushi
AU - Li, Chun Zhu
AU - Chiba, Tadatoshi
PY - 2002/10/1
Y1 - 2002/10/1
N2 - Two pairs of raw and acid-washed coal samples were prepared from Yallourn and Loy Yang brown coals, and subjected to rapid pyrolysis in a drop-tube reactor at 1073-1173 K in a stream of N2 or H2O/N2 mixture. Examinations were made on the roles of the inherent metallic species in the secondary reactions of nascent tar and char that were formed by the intraparticle primary reactions. The experimental results revealed that the inherent metallic species were essential for vary rapid steam reforming/gasification of the nascent tar/char and simultaneous suppression of soot formation. In the absence of the metallic species, the soot formation from the tar accounted as much as 15-19 and 6-13% of the carbon in coal in N2 and H2O/N2, respectively. The metallic species reduced the yield of soot to 6-8% in N2 by enhancing the reforming of tar by H2O generated from the pyrolysis of coal. In the H2O/N2 stream, instead of soot formation, a net gasification conversion up to 17% within 4.3 s was observed in the presence of the metallic species as a result of catalytic gasification of the nascent char. Moreover, the metallic species catalyzed the steam reforming of the nascent tar, giving its conversion up to 99%. Over the range of the conditions employed, a one-to-one stoichiometry was established between the steam consumption and the yield of carbon oxides formed by the steam reforming/gasification and water-gas-shift reaction.
AB - Two pairs of raw and acid-washed coal samples were prepared from Yallourn and Loy Yang brown coals, and subjected to rapid pyrolysis in a drop-tube reactor at 1073-1173 K in a stream of N2 or H2O/N2 mixture. Examinations were made on the roles of the inherent metallic species in the secondary reactions of nascent tar and char that were formed by the intraparticle primary reactions. The experimental results revealed that the inherent metallic species were essential for vary rapid steam reforming/gasification of the nascent tar/char and simultaneous suppression of soot formation. In the absence of the metallic species, the soot formation from the tar accounted as much as 15-19 and 6-13% of the carbon in coal in N2 and H2O/N2, respectively. The metallic species reduced the yield of soot to 6-8% in N2 by enhancing the reforming of tar by H2O generated from the pyrolysis of coal. In the H2O/N2 stream, instead of soot formation, a net gasification conversion up to 17% within 4.3 s was observed in the presence of the metallic species as a result of catalytic gasification of the nascent char. Moreover, the metallic species catalyzed the steam reforming of the nascent tar, giving its conversion up to 99%. Over the range of the conditions employed, a one-to-one stoichiometry was established between the steam consumption and the yield of carbon oxides formed by the steam reforming/gasification and water-gas-shift reaction.
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U2 - 10.1016/S0016-2361(02)00128-X
DO - 10.1016/S0016-2361(02)00128-X
M3 - Article
AN - SCOPUS:0036771669
VL - 81
SP - 1977
EP - 1987
JO - Fuel
JF - Fuel
SN - 0016-2361
IS - 15
ER -