Kinetic Properties Of The Components Of Douglas-fir And The Heat Of Combustion Of Their Volatile Pyrolysis Products

Authors

  • William J. Parker
  • Susan L. LeVan

Keywords:

Cellulose, lignin, mannan, xylan, wood, heat of combustion, activation energy, pyrolysis

Abstract

Specimens of the chemical components of Douglas-fir, which include cellulose, lignin, mannan, and xylan, were pyrolyzed in nitrogen in the temperature range between 290 and 370 C, which is characteristic of the pyrolysis temperature range of wood in a fire environment. From these data, the effective activation energy, preexponential factor, and the net heat of combustion of the volatiles were calculated as a function of the mass retention fraction of the specimen. These kinetic parameters were used to calculate the mass loss rate of Douglas-fir and a prepared mixture of the components in a pyrolyzer based on their measured temperature histories. The calculated mass loss rates were within a factor of two of the measured values.

References

Atreya, A. 1983. Pyrolysis, ignition and fire spread on horizontal surfaces of wood. Ph.D. thesis, Harvard Univ.nBeall, F. C., and H. W. Eickner. 1970. Thermal degradation of wood components: A review of the literature. USDA Forest Serv. Res. Pap. FPL 130, Forest Prod. Lab., Madison, WI. 26 pp.nHuggett, C. 1980. Estimation of the rate of heat release by oxygen consumption measurements. Fire Mater. 4:61-65.nLipska, A. E., and F. A. Wodley. 1969. Isothermal pyrolysis of cellulose: Kinetics and gas chromalographic mass spectrometric analysis of the degradation products. J. Applied Polymer Sci. 13:851-865.nObst, J. 1982. Frequency and alkali resistance of lignin-carbohydrate bonds in wood. Tappi 65(4): 109-112.nParker, W. J. 1985a. Development of a model for the heat release rate of wood—A status report. NBSIR 85-3163, Natl. Bur. Stand. (U.S.)nParker, W. J. 1985b. Prediction of the heat release rate of wood. Pages 207-216 in Fire safety science, Proceedings of the First International Symp., Hemisphere Publ. Corp.nParker, W. J. 1988. Determination of input data for a model of the heat release rate of wood. Pages 105-115 in J. R. Mehaffey, ed. Mathematical modeling of fires. ASTM Special Tech. Publ. (STP) 983, ASTM, Philadelphia, PA.nRamiah, M. V. 1970. Thermogravimetric and differential thermal analysis of cellulose, hemicellulose, and lignin. J. Appl. Polym. Sci. 14:1323-1337.nRoberts, A. F. 1970. A review of kinetics data for the pyrolysis of wood and related substances. Combust, and Flame 14:261-272.nSjostrom, E. 1981. Wood chemistry: Fundamentals and applications. Academic Press, Inc.nSusott, R. A. 1982. Characterization of the thermal properties of forest fuels by combustible gas analysis. Forest Sci. 28(2):404-420.nTang, W. K. 1967. Effect of inorganic salts on pyrolysis of wood alpha-cellulose and lignin determined by dynamic thermogravimetry. USDA Forest Serv. Res. Pap. FPL 71, Forest Products Lab., Madison, WI. 16 pp.nThompson, N. S., and O. A. Kaustinen. 1972. Alteration of the physical properties of fibers and paper from coniferous holocelluloses by chemical means. Tappi Spec. Tech. Assoc. Publ. 8:146-152.nTimell, T. E. 1964. Wood hemicelluloses: Part I. Advances in Carbohydrate Chemistry and Biochemistry 19:247-302.nTimell, T. E. 1965. Wood hemicelluloses: Part II. Advances in Carbohydrate Chemistry and Biochemistry 20:409-483.n

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Published

2007-06-22

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Research Contributions