skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Kinetics and mechanisms of NO{sub x}: Char reduction. Quarterly technical progress report, 31 January 1995--30 April 1995

Technical Report ·
DOI:https://doi.org/10.2172/93653· OSTI ID:93653

This project is concerned with the mechanism of reduction of both NO and N{sub 2}O by carbons. It was recognized some years ago that NO formed during fluidized bed coal combustion can be heterogeneously reduced in-situ by the carbonaceous solid intermediates of combustion. This has been recently supplemented by the knowledge that heterogeneous reaction with carbon can also play an important role in reducing emissions of N{sub 2}, but that the NO-carbon reactions might also contribute to formation of N{sub 2}. The precise role of carbon in N{sub 2} reduction and formation has yet to be established. Interest in the N{sub 2} and N{sub 2}O-char reactions has been significant in connection with both combustor modeling, as well as in design of post-combustion NO{sub x} control strategies. In our studies, a DuPont thermogravimetric analyzer (TGA) is used for the char reactivity studies. The temperature and mass are recorded as function of time, using a Macintosh computer and software for simultaneous apparatus control and data acquisition. Specific surface areas of char samples were determined by the N{sub 2} BET method at 77 K. A standard flow-type adsorption device (Quantasorb) was used for the measurements. Prior to surface area analysis, all samples were outgassed in a flow of nitrogen at 573 K for 3 hours. The carbonaceous solids used were resin char, graphite, coconut char and a Wyodak coal char. As was noted in the last report, carbons derived from different original materials show quite similar behaviors, in terms of the trends, but there are significant differences in actual reaction rates. It was shown that the spread of the reaction rate data from different studies, when expressed on a mass of carbon reactant- or surface area-basis, was almost the same.

Research Organization:
Brown Univ., Providence, RI (United States). Div. of Engineering
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FG22-94PC94218
OSTI ID:
93653
Report Number(s):
DOE/PC/94218-3; ON: DE95016264
Resource Relation:
Other Information: PBD: [1995]
Country of Publication:
United States
Language:
English