The loss of Na and Cl during the pyrolysis of a NaCl-loaded brown coal sample
A Victorian brown coal was physically loaded with NaCl and pyrolyzed in a quartz fluidized-bed reactor. The fluidized-bed reactor was equipped with a quartz frit in the freeboard zone to enable the total devolatilization of the coal particles. The introduction of NaCl into the coal has caused only minor reductions in the weight loss. A significant amount of chlorine was volatilized during pyrolysis at temperatures as low as 200 C. At temperatures around 400--500 C where the loss of sodium was not very significant, about 70% of chlorine was volatilized from the coal particles. With the volatilization of chlorine at this temperature level, sodium must have been bonded to the char matrix. With increasing temperature, the volatilization of chlorine decreased and then increased again, whereas the volatilization of sodium increased monotonically with increasing temperature. Almost all the Na in coal could be volatilized at temperatures higher than about 800 C. These experimental results clearly indicate that chlorine and Na interacted strongly with coal/char at high temperatures. Na and Cl in the coal did not volatilize as NaCl molecules. Significant amounts of species containing a COO-group such as acetate, formate and oxalate were observed in the pyrolysis products although the exact forms of these species (i.e., as acids, salts or esters) in the pyrolysis product remain unknown. The yields of the species containing a COO-group decreased with increasing temperature, possibly due to the intensified thermal cracking reactions at high temperatures.
- Research Organization:
- Monash Univ., Clayton, Victoria (AU)
- OSTI ID:
- 20082261
- Resource Relation:
- Conference: Sixteenth Annual International Pittsburgh Coal Conference, Pittsburgh, PA (US), 10/11/1999--10/15/1999; Other Information: 1 CD-ROM. Operating systems required: Windows 95/98; Windows 3.X, Macintosh; PBD: 1999; Related Information: In: Sixteenth annual international Pittsburgh Coal Conference: Proceedings, [2000] pages.
- Country of Publication:
- United States
- Language:
- English
Similar Records
The devolatilization of coal and a comparison of chars produced in oxidizing and inert atmospheres in fluidized beds
Effects of pretreatment in steam on the pyrolysis behavior of Loy Yang brown coal