ECN publication
Title:
Devolatilisation of pulverised coal: experiments in ECN's AEFGC-simulator
 
Author(s):
 
Published by: Publication date:
ECN 1995
 
ECN report number: Document type:
ECN-I--95-028 Other
 
Number of pages: Full text:
43 Download PDF  

Abstract:
The devolatilisation behaviour of Goettelborn coal was studied in alab-scale coal characterisation facility, the so-called Atmospheric Entrained-Flow Gasification and Combustion simulator (AEFGC-simulator). Volatile matter yield and nitrogen release were determined for three size fractions, viz. 44-63, 75-90 and 125-150 mum, and two operating modes. In mode 1, a staged flat flame (methane/oxygen/nitrogen) burner was used as the heat source and to provide the desired gaseous environment for the coal particles, along with an electrically heated wall extending from the burner. In this mode, the particle heating rate was in the order of 105 deg C/s and the final gas temperature was 1000C or 1400C at a wall temperature of 1000C or 1500C respectively. In mode 2, the facility was operated without the gas burner, with typical particle heating rates of 103C/s and a final gas temperature of approx. 850C. In this mode experiments were conducted in a 100% nitrogen atmosphere. In general, the actual volatile matter yield was found to be 1-2.5 times higher than the proximate volatile matter yield. Particle size appeared to have a significant influence on both the volatile matter yield and nitrogen release in operating mode 1. Smaller particles resulted in higher volatile matter yields and nitrogen releases than larger particles. In operating mode 2, however, the effects of particle size on volatile matter yield and nitrogen release were found to be less significant. Both the volatile matter yield and the nitrogen release in operating mode 1 were considerably larger than in operating mode 2. This was attributed to the large differences in heating rate and final temperature. Since the conditions for operating mode 1 are much more representative for the actual conditions in entrained-flow gasification and pulverised fuel combustion processes, operating mode 1 is clearly to be preferred over operating mode 2. The present test results indicate that the concept of using a staged flat flame burner in conjunction with an electrically heated wall extending from the burner is appropriate for low-cost lab-scale devolatilisation studies of pulverised coal. 18 figs., 6 tabs., 22 refs.


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