Environment and Ecology Research Vol. 5(1), pp. 6 - 12
DOI: 10.13189/eer.2017.050102
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A Chemical Mechanism for Self-ignition in a Peat Stack

Kari I. Hänninen ^*
Department of Biological and Environmental Sciences, University of Jyvaskyla, Finland

ABSTRACT

Two lowest excited energy states of the ground state molecule, and , exist in troposphere. They are called as singlet oxygen molecules. The mechanism leading to their formation in the peat stack is indirect photolysis. Almost all chromophores which absorb UV/visible radiation are able to transfer the needed excitation energy to molecules. The decomposition process of organic material (OM) in the peat stack raises its temperature and produces volatile organic compounds (VOCs), and humified OM with conjugated double bond structures. This increases the efficiency of indirect photolysis. The residence time of 14 minutes allows to accumulate in sufficiently rich atmosphere inside the stack. Excess energies of and heat the system and creates from VOCs/OM hydroxyl and peroxyl radicals which further propagate exothermic reactions. These natural heating mechanisms may locally add enough to the overall stack temperature of 50 to 70℃ to trigger self-ignition of VOCs. Sporadic but frequent micro-fires may generate hot spots of carbonaceous char, which achieve and maintain temperatures of 170 to 220℃. This heat generates hot spots of smouldering fire, which may further develop to ember stage. Finally, if wind inflames, an open fire may eventually evolve in the peat stack.

KEYWORDS
Singlet Oxygen Molecules, Triggering Self-ignition, Peat Stack

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Kari I. Hänninen , "A Chemical Mechanism for Self-ignition in a Peat Stack," Environment and Ecology Research, Vol. 5, No. 1, pp. 6 - 12, 2017. DOI: 10.13189/eer.2017.050102.

(b). APA Format:
Kari I. Hänninen (2017). A Chemical Mechanism for Self-ignition in a Peat Stack. Environment and Ecology Research, 5(1), 6 - 12. DOI: 10.13189/eer.2017.050102.