Catalytic direct liquefaction of high-sulfur coals and their blends with asphaltite in the absence of a solvent
- Cukurova Universitesi, Adana (Turkey)
Two high-sulfur Turkish coals (Mengen and Kangal) and an asphaltite (Avgamasya) were liquefied with and without the catalyst precursors ammonium heptamolybdate (AHM) and ammonium tetrathiomolybdate (ATTM) at 300, 350, 400, and 450{sup o}C. Blends of these coals with the asphaltite were also liquefied using ATTM. Effective conversions of both coals into oils and into asphaltene and preasphaltene fractions were achieved with both catalyst precursors, although ATTM was more effective than AHM. Maximum conversion for Mengen coal with ATTM (89.2%) was achieved at 400{sup o}C, although the maximum yield of oils (56.9%) was obtained at 450{sup o}C. Kangal, in the presence of ATTM, gave maximum conversion (87.7%) at 400{sup o}C; the corresponding oil yield (49.6%) was not much less than that obtained at 450{sup o}C (49.9%). Some retrogressive reactions toward the formation of aromatics were observed during liquefaction at 450{sup o}C in the presence of AHM or ATTM with both coals. Also, using these catalyst precursors results in effective hydrogenation of two-ring or higher condensed aromatics and effective hydrogenolysis of the alicyclic part of hydroaromatic structures. On the other hand, these catalyst precursors do not provide effective saturation of monoaromatic rings, although the use of ATTM yielded partial reduction of these compounds. The distribution of main product fractions obtained from these reactions and the detailed analysis of oils obtained are reported. 118 refs., 4 figs., 15 tabs.
- OSTI ID:
- 20939424
- Journal Information:
- Energy and Fuels, Vol. 21, Issue 4; Other Information: omergul@psu.edu; ISSN 0887-0624
- Country of Publication:
- United States
- Language:
- English
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