Solid Residues of Lignite Hydrogenation:News from Petrography and NMR Spectroscopy

摘要

Fluorescence microscopy as well as ~(13)C-CP/MAS-NMR spectroscopy are applied to characterizehydrogenation residues of lignite lithotypes. The combination of the microscopic and spectroscopictechniques allows a detailed description of the coal decomposition during the liquefactionprocess under several conditions. Particularly, different decomposition steps in the coal networkcan be detected by means of the NMR method used. A quantitative component analysis of thehydrogenation residues is performed applying fluorescence microscopy. A new kind of residuecomponent is detected indicating mild hydrogenation conditions for lignites. Furthermore, theconversion of the lignite macerals under different hydrogenation conditions is studied to obtaininformation on the formation of typical residue constituents. Although the techniques applieddeviate strongly it is possible to demonstrate the influence of typical liquefaction conditions, suchas hydrogen deficiency or reaction temperature, as well as in the petrographic and in the spectroscopicresults. While the ~(13)C CP/MAS NMR allows a quantitative analysis of the remaining organicmatter of the coals the fluorescence microscopy confirms the formation of typical componentsshowing dependence on hydrogenation conditions.