Hydrogen transferring liquefaction using hydrogenated fluoranthene at high temperatures was very effective for three Japanese bituminous coals, with a total yield of oil and asphaltene > 85 wt%. The high temperatureshort contact time conditions (480ยฐC for 10 min or 510ยฐC for 2.5 min) resulted in a t
The roles of vehicle and gaseous hydrogen during short contact time coal liquefaction
โ Scribed by Bruce R. Utz; Herbert R. Appell; Bernard D. Blaustein
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 670 KB
- Volume
- 65
- Category
- Article
- ISSN
- 0016-2361
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โฆ Synopsis
The roles of the vehicle and gaseous hydrogen during short contact time liquefaction (SCTL) in microreactors were examined by using a number of synthetic vehicles. The importance of vehicles during SCTL was evaluated on their ability to convert coal to tetrahydrofuran (THF)-soluble products. Reaction conditions were three minutes at 425ยฐC following a one minute heat-up. Although the consumption of hydrogen (hydrogen donor or gaseous hydrogen) by reactive coal fragments is minimal during the early stages of liquefaction (as in SCTL reactions), hydrogen donors were important and could be ranked according to the extent of conversion to THF-soluble products (tetrahydroquinoline > hydrogenated pyrene > dihydro-anthracene=dihydrophenanthrene> tetralin). The importance of gaseous hydrogen was also studied. Gaseous hydrogen was needed if either quality or quantity of hydrogen donor was not adequate in a SCTL reaction. With certain synthetic vehicles, the SCTL stage of an integrated two-stage liquefaction process could be conducted in the absence of hydrogen. Solubility properties that might enhance solubilization of coalderived products, and therefore the extent of liquefaction, were examined by varying the concentration of certain components (mcresol and quinoline) of the synthetic vehicle mixtures. Solubility effects were minimal.
๐ SIMILAR VOLUMES
In the two stage liquefaction of Wandoan subbituminous coal it was found that the coal was effectively converted into THF-soluble products with high conversion and low hydrogen consumption by pyrolytic procedures in a N,-tetralin system, using relatively low heating rates, high temperature and short
The thermodynamic equilibrium constants for the reduction of oxygen and sulphur functional groups in hydrogen and in tetralin were calculated for the temperature range 327-527ยฐC. All the reduction reactions of the oxygen groups are thermodynamically favourable both with hydrogen and with tetralin.