Thermogravimetric analyses of coal, feedlot biomass and blends in inert and oxidizing atmospheres

B. Thien, K. Annamalai, D. B. Bukur

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

In the Texas Panhandle area, almost 10 million tons of feedlot wastes are generated every year. Not all the waste produced by the cattle can be used as fertilizer, and its storage and disposal present an environmental challenge. If the manure is simply stockpiled, it will cause air and water runoff pollution. One possible solution to the problem is to co-fire the high moisture high, ash manure with coal at a mass ratio of 10:90 feedlot biomass: coal (4:96 on a heat basis) in a utility boiler in order to produce useful heat or electricity. When manure is used in this manner, it is referred to as feedlot biomass (FB), to emphasize its utility and economic value. Unfortunately, FB is not an ideal fuel, and is hard to fire because of its high moisture and ash content. The high moisture and ash in FB can create flame stability and ash fouling problems when FB is used as a fuel source. Experiments were conducted in a Thermogravimetric Analyzer (TGA) in both air and nitrogen in order to obtain pyrolysis and ignition characteristics of FB. In TGA, a sample of fuel is heated at a specified heating rate, mass is measured with an electronic balance and the temperature is recorded with a thermocouple. The resulting traces can then be used to determine the ash content, the dry loss, the ignition temperature, and the kinetics of devolitization. Using the parallel reaction model, devolitization kinetic constants were obtained by curve fitting the mass traces. The parallel reaction model assumes that many normally distributed devolitization reactions proceed simultaneously. The results indicate that the feedlot biomass has a higher ash content than coal, and a greater proportion of the dry ash free fuel in the form of volatiles. Further, feedlot biomass volatilizes at a lower temperature than coal, and has a lower activation energy. Further results indicate that feedlot biomass also has a lower ignition temperature. The lower activation energy, lower ignition temperature, and lower pyrolysis temperature translate to a faster release of volatiles during combustion. Typically the faster release of volatiles will increase the stability of co-fired feedlot biomass flames, reduce the formation of harmful pollutants such as NO and increase fuel burnout.

Original languageEnglish
Title of host publicationProceedings of the 2001 International Joint Power Generation Conference, Volume 1
Subtitle of host publicationFuel and Combustion Technologies
Pages197-204
Number of pages8
Publication statusPublished - 1 Dec 2001
Event2001 International Joint Power Generation Conference - New Orleans, LA, United States
Duration: 4 Jun 20017 Jun 2001

Publication series

NameProceedings of the International Joint Power Generation Conference
Volume1

Other

Other2001 International Joint Power Generation Conference
CountryUnited States
CityNew Orleans, LA
Period4/6/017/6/01

ASJC Scopus subject areas

  • Energy(all)

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  • Cite this

    Thien, B., Annamalai, K., & Bukur, D. B. (2001). Thermogravimetric analyses of coal, feedlot biomass and blends in inert and oxidizing atmospheres. In Proceedings of the 2001 International Joint Power Generation Conference, Volume 1: Fuel and Combustion Technologies (pp. 197-204). (Proceedings of the International Joint Power Generation Conference; Vol. 1).