UV spectral Analysis of Pyrolysis residues


Czinkota Imre1, Simándi Péter2, Somogyi Ferenc1, Rácz Istvánné2, Tolner László1

1Szent István University, Faculty of Agriculture and Environmental Sciences, H-2103 Gödöllő, Páter K. u. 1, Hungary

2Szent István University, Faculty of Economics, Agricultural and Health Studies, H-5540 Szarvas, Szabadság. u. 1-3 Hungary


During the process of anaerobic thermal degradation of organic materials (pyrolysis) gas, liquid and solid products are formed. Solid residue of pyrolysis of different polymers was investigated at different temperatures and heating programs. Extracts of the residues of pyrolysis were produced with various polar solvents like water, methanol, and hexane. Looking at the characteristics of the spectra of extracts in UV range we found significant differences. The material characteristics of the starting polymers and the conditions of the pyrolysis are both having specific effects on the examined spectras. For hydrocarbons, at the 200-400 nm range, mainly the molecules with conjugated double bond (molecules with delocalized Pi electron systems) are showing absorption. Supposing the uniform distribution of Pi electron systems, the shape of spectra was analyzed and modeled; the thermal fragmentation processes can be featured using simple theories of thermodynamics. Molecule parts and functional groups containing some heteroatoms can also show absorption in this wavelength range, in their spectra, some absorption peaks of monomers can be found also. Optical spectroscopy of the pyrolysis residue extracts is a simple and effective method. Therefore the UV spectroscopy could be suitable for statistical analysis of evolving complexes, and follow-up the process of pyrolysis of varied molecules. This work was supported by the TÁMOP-4.2.2.A-11/1/KONV-2012-0015 program of the Hungarian National Development Agency.