Characterization of the thermal degradation and heat of combustion of Pinus halepensis needles treated with ammonium-polyphosphate-based retardants

Article

Abstract

The thermal degradation behavior of P. halepensis needles treated with two ammonium-polyphosphate-based commercial retardants was studied using thermal analysis (DTG) under nitrogen atmosphere. Moreover, for the same experimental material, the heat of combustion of the volatiles was estimated based on the difference between the heat of combustion of the fuel and the heat contribution of the charred residue left after pyrolysis. The heat of combustion of the volatiles was exponentially related to the retardant concentration of the samples. In the range of retardant concentrations from 10 to 20% w/w the mean reduction percentage of the heat of combustion of the volatiles, with respect to untreated samples, was 18%.

Keywords

Bomb calorimeter Char Forest fires Heat of combustion Long-term retardants Thermal analysis Volatiles 

List of symbols

APP

Ammonium polyphosphate

DTG

Differential thermogravimetry

DR

DTG peak decomposition rate (103 s−1)

EHC

Effective heat of combustion (MJ kg−1 fuel consumed)

FT1

Fire-Trol 931

FT4

Fire-Trol 934

HC

Heat of combustion (MJ kg−1)

HHC

High heat of combustion (MJ kg−1)

HY

Heat yield (MJ kg−1)

hc/r0)

Heat of combustion released per kg of oxygen consumed (13.1 MJ kg−1)

\( \Updelta h_{{dsp\;{\rm H_{2}O}}} \)

Heat of desorption of bound water in the fuel (MJ kg−1)

\( \Updelta h_{{v\;{\rm H_{2}O}}}\)

Latent heat of vaporization of water at 100 °C (MJ kg−1)

LHC

Low heat of combustion (MJ kg−1)

\({\dot{m}}_{\rm {O_{2},\infty }} \)

Oxygen mass flow at ambient conditions (kg s−1)

\( {\dot{m}}_{\rm{O_{2}}} \)

Instaneous oxygen mass flow (kg s−1)

PH

Pinus halepensis

\({\dot{q}}\)

Heat rate (kW)

Qinc

Heat loss due to incomplete combustion (MJ kg−1)

Qrad

Heat loss due to radiation losses (MJ kg−1)

R550

Percentage of residual mass at 550 °C to initial mass at 150 °C (% w/w)

PT

DTG peak temperature (°C)

Xc

Char yield (% w/w)

XH

Percentage of hydrogen (% w/w)

Xr

Retardant concentration (% w/w)

Xw

Moisture content on a dry basis (% w/w)

Subscripts/superscripts

c

Charred residue

f

Fuel

r

Retardant

vol

Volatiles

1, 2, 3

Peak number in DTG graphs

References

  1. 1.
    USDA Forest Service: specification for long-term retardants, wildland fire fighting 5100-304c. Technical document; 2007.Google Scholar
  2. 2.
    Sekiguchi Y, Shafizadeh F. The effect of inorganic additives on the formation, composition, and combustion of cellulosic char. J Appl Polym Sci. 1984;29:1267–86.CrossRefGoogle Scholar
  3. 3.
    Àgueda A, Pastor E, Planas E. Different scales for studying the effectiveness of long-term forest fire retardants. Prog Energy Combust Sci. 2008;34:782–96.CrossRefGoogle Scholar
  4. 4.
    Liodakis S, Antonopoulos I, Agiovlasitis I, Kakardakis T. Testing the fire retardancy of Greek minerals hydromagnesite and huntite on WUI forest species Phillyrea latifolia L. Thermochim Acta. 2008;469:43–51.CrossRefGoogle Scholar
  5. 5.
    Mostashari SM, Mostashari SZ. Combustion pathway of cotton fabrics treated by ammonium sulfate as a flame-retardant studied by TG. J Therm Anal Calorim. 2008;91:437–41.CrossRefGoogle Scholar
  6. 6.
    George C, Blakely A, Johnson G, Simmerman D. Evaluation of liquid ammonium polyphosphate fire retardants. USDA Forest Service, Intermountain Forest and Range Experiment Station General Technical Report INT-41, Ogden, UT; 1977.Google Scholar
  7. 7.
    Byram G. Combustion in forest fuels. In: Davis KP, editor. Forest fire control and use. New York: McGraw-Hill; 1959. p. 61.Google Scholar
  8. 8.
    Alexander M. Calculating and interpreting forest fire intensities. Can J Bot. 1982;60:349–57.Google Scholar
  9. 9.
    Susott R. Characterization of the thermal properties of forest fuels by combustible gas analysis. For Sci. 1982;28:404–20.Google Scholar
  10. 10.
    Wilson R. Observations of extinction and marginal burning states in free burning porous fuel beds. Combust Sci Technol. 1985;44:179–93.CrossRefGoogle Scholar
  11. 11.
    Dibble A, White R, Lebow P. Combustion characteristics of north-eastern USA vegetation tested in the cone calorimeter: invasive versus non-invasive plants. Int J Wildland Fire. 2007;16:426–43.CrossRefGoogle Scholar
  12. 12.
    Huggett C. Estimation of rate of heat release by means of oxygen consumption measurements. Fire Mater. 1980;4:61–5.CrossRefGoogle Scholar
  13. 13.
    Susott R, Shafizadeh F, Aanerud T. A quantitative thermal analysis technique for combustible gas detection. J Fire Flammabl. 1979;10:94–104.Google Scholar
  14. 14.
    Weise D, White R, Beall F, Etlinger M. Use of the cone calorimeter to detect seasonal differences in selected combustion characteristics of ornamental vegetation. Int J Wildland Fire. 2005;14:321–38.CrossRefGoogle Scholar
  15. 15.
    Babrauskas V. Development of the cone calorimeter—A bench-scale heat release rate apparatus based on oxygen consumption. Fire Mater. 1984;8:81–95.CrossRefGoogle Scholar
  16. 16.
    LeVan S. The chemistry of fire retardancy. In: Rowell RM, editor. The chemistry of solid wood, Advances in Chemistry Series 207, Washington, DC; 1984. p. 531.Google Scholar
  17. 17.
    Liodakis S, Vorisis D, Agiovlasitis I. Testing the retardancy effect of various inorganic chemicals on smoldering combustion of Pinus halepensis needles. Thermochim Acta. 2006;444:157–65.CrossRefGoogle Scholar
  18. 18.
    Catchpole WR, Catchpole EA, Tate AG, Butler B, Rothermel RC. A model for the steady spread of fire through a homogeneous fuel bed. In: Proceedings of the 4th international conference on Forest Fire Research, Coimbra (Portugal), 2002, CD-Rom.Google Scholar
  19. 19.
    Dupuy JL, Maréchal J, Morvan D. Fires from cylindrical forest fuel burner: combustion dynamics and flame properties. Combust Flame. 2003;135:65–76.CrossRefGoogle Scholar
  20. 20.
    Di Blasi C, Branca C, Galgano A. Effects of diammonium phosphate on the yields and composition products from wood pyrolysis. Ind Eng Chem Res. 2007;46:430–8.CrossRefGoogle Scholar
  21. 21.
    Levchik GF, Levchik SV, Sachok PD, Selevich AF, Lyakhov AS, Lesnikovich AI. Thermal behaviour of ammonium polyphosphate-inorganic compound mixtures. Part 2. Manganese dioxide. Thermochim Acta. 1995;257:117–25.CrossRefGoogle Scholar
  22. 22.
    Mészáros E, Jakab E, Várhegyi G, Szepesváry P, Marosvölgyi B. Comparative study of the thermal behavior of wood and bark of young shoots obtained from an energy plantation. J Anal Appl Pyrol. 2004;72:317–28.CrossRefGoogle Scholar
  23. 23.
    Liodakis S, Vorisis D, Agiovlasitis IP. A method for measuring the relative particle fire hazard properties of forest species. Thermochim Acta. 2005;437:150–7.CrossRefGoogle Scholar
  24. 24.
    Liodakis S, Kakardakis T. Measuring the relative particle foliar combustibility of WUI forest species located near Athens. J Therm Anal Calorim. 2008;93:627–35.CrossRefGoogle Scholar
  25. 25.
    Susott R, DeGroot W, Shafizadeh F. Heat content of natural fuels. J Fire Flammabl. 1975;6:311–25.Google Scholar
  26. 26.
    Shafizadeh F, Sekiguchi Y. Development of aromaticity in cellulosic chars. Carbon 1983;21:511–6.CrossRefGoogle Scholar
  27. 27.
    Di Blasi C, Branca C, Galgano A. Thermal and catalytic decomposition of wood impregnated with sulfur- and phosphorus-containing ammonium salts. Polym Degrad Stab. 2008;93:335–46.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2009

Authors and Affiliations

  1. 1.Centre d’Estudis del Risc Tecnològic (CERTEC)Universitat Politècnica de CatalunyaBarcelona, CataloniaSpain
  2. 2.Laboratory of Inorganic and Analytical Chemistry, Department of Chemical EngineeringNational Technical University of Athens (NTUA)AthensGreece

Personalised recommendations