Transformation of functional forms of nitrogen in polymeric N-heterocyclic compounds during pyrolysis

摘要

The knowledge of the nitrogen functionalities in coals and their pyrolysis products is important to conclude on the mechanisms of NO_x-formation during combustion. To investigate the transformations of nitrogen funktionalities pyrolysis experiments were carried out with polymeric model substances containing defined forms of nitrogen bond. The functionalities of the nitrogen retained in the chars were determined by XPS. Additional information about the structure were received from FT-i.r.). It is interesting to note that the nitrogen in 5-membered rings of the N-5 heterocyclic compounds remains in existence in the pyrolysis products up to 900°C. A comprehensible mechanism of the transformation of N-6 into N-5 nitrogen will be discussed on the basis of the FT-i.r.-spectra of the low temperature chars.