Effects of experimental conditions on the formation of NH{sub 3}, HCN and H{sub 2}S during the pyrolysis of a brown coal

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20082272

Tan, L L; Li, C Z

A Victorian brown coal was pyrolyzed in a quartz reactor. The reactor has some features of a drop-tube reactor and of a fixed-bed reactor, capable of operating at fast and slow heating rates. Experimental results indicated that thermal cracking of char was an important source of NH{sub 3}, H{sub 2} and HCN (as well as H{sub 2}S) during the pyrolysis of the brown coal. The yield of HCN was found to change with gas flow rate and coal feeding rate, suggesting that HCN (or its precursors) could interact significantly with the nascent char but not to yield NH{sub 3}. The yields of HCN and NH{sub 3} were both sensitive to changes in heating rate. The effects of heating rate could be partly explained by the graphitization/condensation reactions, making the N-containing heteroaromatic ring systems increasingly stable, during the extended holding at high temperatures at the slow heating rate. Experimental results indicated that HCN does not significantly convert to NH{sub 3}, either on the char surface or in the gas phase, at least during the pyrolysis of the brown coal. The changes in heating rate or coal feeding rate did not affect significantly the formation of H{sub 2}S.

• Research Organization: Monash Univ., Clayton, Victoria (AU)
• OSTI ID: 20082272
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
AMMONIA
BROWN COAL
CHARS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
HYDROCYANIC ACID
HYDROGEN
HYDROGEN SULFIDES
PYROLYSIS
SENSITIVITY ANALYSIS
THERMAL CRACKING