Five coals, ranging in rank from subbituminous to high-volatile A bituminous, were examined by 13C NMR and flash pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). They were also subjected to liquefaction in batch microautoclave reactors at three sets of conditions: 360 °C for 1 h in pyrene; 425 °C similarly; and temperature-programmed liquefaction for 15 min at 200 °C and 30 min at 425 °C in 9,10-dihydrophenanthrene with a sulfided molybdenum catalyst. Four of the five coals showed good relationships between the structural fragments observed in Py-GC/MS and the dominant compound types in the hexane-soluble products from liquefaction at temperatures ≥400 °C. For example, DECS 12 Pittsburgh seam hvA bituminous coal showed a dominance of alkylnaphthalenes in the pyrogram, and this compound class was also dominant in the gas chromatogram of the hexane solubles. 13C NMR showed a relationship of faH to conversion of coal to liquids at 425 °C for 1 h. The combination of 13C NMR and Py-GC/MS is useful for determining the probable light reaction products of direct liquefaction. The correlations indicate relationships between the compositions of the light fraction of the liquefaction products and coal structural information. The combined characterization approach described here could be used for screening of a wide suite of candidate feedstocks to winnow a few promising candidates for detailed testing.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology