Modification of Reactivity and Strength of Formed Coke from Victorian Lignite by Leaching of Metallic Species

被引:15
作者
Karnowo [1 ]
Kudo, Shinji [1 ,2 ]
Mori, Aska [2 ]
Zahara, Zayda Faizah [1 ]
Norinaga, Koyo [1 ,2 ]
Hayashi, Jun-ichiro [1 ,2 ,3 ]
机构
[1] Kyushu Univ, Interdisciplinary Grad Sch Engn Sci, Kasuga, Fukuoka 8168580, Japan
[2] Kyushu Univ, Inst Mat Chem & Engn, Kasuga, Fukuoka 8168580, Japan
[3] Kyushu Univ, Res & Educ Ctr Carbon Resources, Kasuga, Fukuoka 8168580, Japan
基金
日本学术振兴会;
关键词
coke; lignite; reactivity; strength; metallic species; leaching; organic acid; LOW-RANK COALS; OXIDATIVE-DEGRADATION METHOD; HEAT-TREATED COALS; BROWN-COAL; IRON COKE; PYROLYSIS; GASIFICATION; TEMPERATURE; BEHAVIOR; ALKALI;
D O I
10.2355/isijinternational.55.765
中图分类号
TF [冶金工业];
学科分类号
0806 ;
摘要
Binder less briquetting of lignite at 100-200 degrees C and subsequent carbonization produces formed coke with tensile strength (ST) of 5-40 MPa, while the briquetting often requires mechanical pressure over 100 MPa. High reactivity is another feature of the lignite-derived coke, and this arises from highly dispersed metallic species such as alkali/alkaline-earth metallic species and ferrous/ferric ones that catalyze CO2 gasification. This work investigated effects of leaching of those metallic species in aqueous solution of hydrochloric acid, acetic acid or oxalic acid on the reactivity and ST of resulting coke from a lignite. The leaching at pH <= 1 removed catalytic metallic species near completely, reducing the coke reactivity by a factor of 8-15. The reduced reactivity was similar to the reactivity of coke from a typical coking coal. The leaching at pH <= 2.2 increased ST from 6 to 13 MPa for briquetting at 200 degrees C and 32 MPa. The performance of leaching with oxalic acid, of that solution had pH of 0.75 at 1 mol/L, was much better than that with acetic acid. This work also examined another type of leaching, oxidation of the lignite in aqueous solution of hydrogen peroxide, which produced organic mono-/di-acids in-situ from the oxidation of aromatic carbons of the lignite. The degree of reduction of the coke reactivity was between that for leaching at pH of 1 and 2. The degradation of macromolecules enhanced plasticizability of the lignite under briquetting and increased ST of the resulting coke to 22 MPa.
引用
收藏
页码:765 / 774
页数:10
相关论文
共 48 条
[1]  
BHATIA SK, 1980, AICHE J, V26, P379, DOI 10.1002/aic.690260308
[2]  
Chafee A. L., 1981, AM CHEM SOC ADV CHEM, V192, P113
[3]   Studies of inorganics added to low-rank coals for catalytic gasification [J].
Domazetis, G ;
Liesegang, J ;
James, BD .
FUEL PROCESSING TECHNOLOGY, 2005, 86 (05) :463-486
[4]  
DURIE RA, 1961, FUEL, V40, P407
[5]  
George A. M., 1991, SCI VICTORIAN BROWN
[6]   Depolymerization of lower rank coals by low-temperature O-2 oxidation [J].
Hayashi, J ;
Matsuo, Y ;
Kusakabe, K ;
Morooka, S .
ENERGY & FUELS, 1997, 11 (01) :227-235
[7]   Rapid conversion of tar and char from pyrolysis of a brown coal by reactions with steam in a drop-tube reactor [J].
Hayashi, J ;
Takahashi, H ;
Iwatsuki, M ;
Essaki, K ;
Tsutsumi, A ;
Chiba, T .
FUEL, 2000, 79 (3-4) :439-447
[8]   Reactions in brown coal pyrolysis responsible for heating rate effect on tar yield [J].
Hayashi, J ;
Takahashi, H ;
Doi, S ;
Kumagai, H ;
Chiba, T ;
Yoshida, T ;
Tsutsumi, A .
ENERGY & FUELS, 2000, 14 (02) :400-408
[9]   Evaluation of macromolecular structure of a brown coal by means of oxidative degradation in aqueous phase [J].
Hayashi, J ;
Aizawa, S ;
Kumagai, H ;
Chiba, T .
ENERGY & FUELS, 1999, 13 (01) :69-76
[10]   REMOVAL OF CALCIUM FROM LOW RANK COALS BY TREATMENT WITH CO2 DISSOLVED IN WATER [J].
HAYASHI, JI ;
TAKEUCHI, K ;
KUSAKABE, K ;
MOROOKA, S .
FUEL, 1991, 70 (10) :1181-1186