ANALYSIS OF PYROLYSIS RESIDUES’ UV-VIS SPECTRUMS

Imre VÁGÓ¹, Imre CZINKOTA², Péter SIMÁNDI³, Istvánné RÁCZ³, László TOLNER²

1) University of Debrecen, Institute of Agricultural Chemistry and Soil Science, H-4015 Debrecen, P.O.Box 36, Hungary. E-mail: vago@agr.unideb.hu

2) Szent István University, Institute of Environmental Science, H-2100 Gödöllő, Hungary

3) Szent István University, Institute of Environmental Science, H-5540 Szarvas, Hungary

Abstract

In the course of the organic matters’ anaerobic thermal degradation (pyrolysis) gas, liquid and solid products are formed. In our laboratory solid phase pyrolysis residues of various polymers were examined. The pyrolysis residues were extracted by different polarity solvents. The UV-VIS absorption spectrums of these extracts were saved. Examining of the characteristic area of the spectrums, specific differences were found. The material qualities of the starting polymers, and the condition of the pyrolysis made specific impact on the examined spectrums. On hydrocarbons, in the wavelength range of 200-800 nm, mainly the conjugated double bonded molecules (delocalized π electron system) show absorption. Molecule parts containing hetero atoms and functional groups are also could show absorption in this wavelength range. With this there can be inferred for the molecular fragments’ material quality which is the result of the pyrolysis process. For polyamides and polyesters, monomers can be found in the pyrolysis residues by this study. The optical analysis of the solvent extracts of the pyrolysis residues is simple and effective method. Therefore the UV-VIS spectroscopy could be able to do the statistical analysis of the evolving, complex and the various molecules.

Our aim was to test a simple method, the measurement of the optical property of the pyrolysis residues’ solvent extract, is able to characterize the pyrolysis process.

Key words: polymer molecules, pyrolysis residues, UV-VIS spectrums