Effect of the coal particle size on pyrolysis and char reactivity for two types of coal and demineralized coal

Journal Article · Tue Jul 15 04:00:00 EDT 2008 · Energy and Fuels

OSTI ID:21084948

Zhu, Wenkui; Song, Wenli; Lin, Weigang ^[1]

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1. Chinese Academy of Sciences, Beijing (China). State Key Laboratory of Multi-phase Complex System

A better understanding of the influence of particle size on pyrolysis and char reactivity is of crucial importance in optimizing the integrated process combining coal topping (coal fast pyrolysis) with char gasification. Different size fractions of two types of coal and demineralized coal were pyrolyzed in a spouted bed. The resulting chars were characterized by X-ray diffraction, and char reactivity was determined in a thermogravimetric analyzer (TGA). Within the range of particle sizes investigated, an increase in particle size results in an increase of char yield, which may be caused by the secondary reactions of volatile matters inside the coal particles. No significant difference in crystallinity was observed for the chars from different size fractions of the parent coals, while more crystallinity was observed for the chars from demineralized coals, which suggests that minerals in the coal play a role in the reduction of char crystallinity during pyrolysis. Char reactivity for raw coals decreased with the increasing of the particle size. For the demineralized coal samples, the change in char reactivity with the increasing of the particle size was reduced. Both the secondary reactions of volatiles and mineral distribution are believed to cause the influence of coal particle size on char reactivity. 19 refs., 7 figs., 3 tabs.

• OSTI ID: 21084948
• Journal Information: Energy and Fuels, Journal Name: Energy and Fuels Journal Issue: 4 Vol. 22; ISSN ENFUEM; ISSN 0887-0624
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
BITUMINOUS COAL
CHARS
COAL GASIFICATION
CRYSTAL STRUCTURE
DEMINERALIZATION
GRAPHITIZATION
LIGNITE
MINERALS
PARTICLE SIZE
PYROLYSIS
REACTIVITY
THERMAL GRAVIMETRIC ANALYSIS
VOLATILE MATTER
X-RAY DIFFRACTION
YIELDS