CHARACTERIZATION OF BIOMASS BURNING: FOURIER TRANSFORM INFRARED ANALYSIS OF WOOD AND VEGETATION COMBUSTION PRODUCTS

Fourier transform infrared (FTIR) examination of combustion products of selected forest products is undertaken to investigate possible satellite remote sensing applications. Pinus strobus (white pine), deciduous Prunus serotina (cherry), Acer rubrum (red maple), Friglans nigra (walnut), Fraxinus americana (ash), Betula papyrifera (birch), Querus alba (white oak) and Querus rubra (red oak) lumber and related samples are combusted in a Meeker burner flame at temperatures ranging from 400 to 900 degrees Fahrenheit. The resulting FTIR signal characteristically produces distinct peaks in the range 400 to 4000 wavenumbers, with distinct maxima in the vicinity of sets at 400-700, 1500-1700, 2200-2400 and 3300-3600 wavenumbers with an intensity range of 47 percent. The evolved absorption amplitude differences, approximately 10 percent, are within the range of detection of modern satellite spectrometers raising the possibility of discriminating between natural forest combustion of different species of vegetation.

Examination of soot and smoke from combusted leaves and branches of the conifer Pinus strobus and deciduous Querus alba (white oak), Querus rubra (red oak), Liquidambar styraciflua (sweetgum), Acer rubrum (maple) and Tilea americana (American basswood) at temperatures of 400 to 900 degrees Fahrenheit produce a similar broad spectrum. Peak locations occur near 1438-1444, 875 and 713 wavenumbers. Relative differences in peak location may distinguish green woods from lumber at natural combustion sites.

Temperature variations during burning show that the spectra of low temperature smoldered aerosols, occurring near 400 to 450 degrees Fahrenheit, is distinguished from soot aerosols generated at 600 degrees Fahrenheit and more elevated temperature. A heightened peak intensity of 50 percent is observed throughout the spectra of the lower temperature generated soot and smoke in comparison to soot and smoke generated at elevated temperature, greater than 600 degrees Fahrenheit. These establish tentative biomass reduction markers based on a wavenumber ratio method.