Hydrocarbons biomass burning

Polycyclic aromatic hydrocarbons (PAHs, sometimes also called polynuclear aromatics, PNA) are a hazardous class of widespread pollutants. The parent structures of the common PAHs are shown in Fig. 4 and the alkylated homologs are generally minor in combustion emissions. PAHs are produced by all natural combustion processes (e.g., wild fires) and from anthropogenic activity such as fossil fuels combustion, biomass burning, chemical manufacturing, petroleum refining, metallurgical processes, coal utilization, tar production, etc. [6,9,15,18, 20,24,131-139]. 

Carbon monoxide is an important trace gas, which has a mean residence time of about two months and a mean concentration of the order of 0.1 ppm. The principal sources of CO are (1) oxidation of methane and other higher hydrocarbons, (2) biomass burning, (3) traffic, industry and domestic heating, (4) oceans, and (5)... 

Jenkins, B. M A. D. Jones, S. Q. Turn, and R. B. Williams, Particle Concentrations, Gas-Particle Partitioning, and Species Intercorrelations for Polycyclic Aromatic Hydrocarbons (PAH) Emitted during Biomass Burning, Atmos. Environ., 30, 3825-3835 (1996). 

Blake DR, Smith Jr. TW, Chen T-Y, Whipple WJ, Rowland FS (1994) Effects of Biomass Burning on Summertime Nonmethane Hydrocarbon Concentrations in the Canadian Wetlands. J Geophys Res 99 1699... 

The contribution of savannah fires exceeds 40% of the global level of biomass burning as a result of which the atmosphere receives minor gas components, such as non-methane hydrocarbons, carbon monoxide, methane, etc., as well as aerosols. According to available estimates for the period 1975-1980, 40%-70% of savannahs were burnt every year, about 6% of such fires took place in Africa. In 1990 about 2 1091 of vegetable biomass were burnt, and as a result 145TgCO got into the atmosphere, which constituted about 30% of anthropogenic CO emissions. 

Barrefors G, Petersson G. 1995. Assessment by gas chromatography and gas chromatography-mass spectrometry of volatile hydrocarbons from biomass burning. J Chromatogr 710 71-77. 

Carbon monoxide (CO) strongly influences the concentration of the radical OH in the tropical atmosphere. CO oxidation can lead to either production or destruction of ozone, depending on the NOx mixing ratio. Tropical soils are either a sink or a weak source of CO, where photochemical oxidation of methane and other hydrocarbons and biomass burning emissions are the predominant CO sources. 

By comparison, the average CO mixing ratio in Earth s troposphere is —0.12 ppmv and it is produced from a variety of anthropogenic and biogenic sources such as fossil fuel combustion, biomass burning, and oxidation of methane and other hydrocarbons. Most of the CO in Earth s troposphere is destroyed by reaction with OH radicals, which are also important for the catalytic... 

O Malley V. P., Burke R. A., and Schlotzhauer W. S. (1997) Using GC-MS/Combustion/lRMS to determine the ratios of individual hydrocarbons produced from the combustion of biomass materials—application to biomass burning. Org. Geochem. 21, 567-581. 

Greenberg, J. P., P. R. Zimmerman, L. Heidt, and W. Pollock (1984). Hydrocarbon and carbon monoxide emissions from biomass burning in Brazil. J. Geophys. Res. 89, 1350-1354. 

Emissions from biomass burning could disrupt the oxidizing potential of the atmosphere. The atmosphere has a self-cleaning mechanism, which photochemically oxidized pollutants, such as hydrocarbons, to carbon dioxide, preventing their buildup... 

However, this effect reverses at localized biomass burning sites. We have discussed previously that biomass smoldering emits nitrogen oxides. Hydrocarbon oxidation in the presence of large amounts of nitrogen oxides creates additional hydroxyl radicals... 

The oxidizing power of the atmosphere has likely decreased significantly, especially in the Northern Hemisphere, as a result of human activities. As a result, the lifetime of methane may have increased by 10-15% since the preindustrial era. At the same time, the abundance of tropospheric ozone has increased perhaps by as much as a factor of 2-3 in the Northern Hemisphere. Enhanced biomass burning fluxes of NO CO, and hydrocarbons from tropical ecosystems are likely to be important. Future changes in tropospheric ozone are predicted to be largest in the tropics (India, China). These projected increases in tropical emissions are likely to have a... 

The global sources and sinks of CO are given in Table 2.14. Methane oxidation (by OH) is a major source of CO, as are technological processes (combustion and industrial processes), biomass burning, and the oxidation of nonmethane hydrocarbons. Uncertainties in each of these estimated sources are large. It is estimated that about two-thirds... 

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