Liquefaction of coal in a flowing-solvent reactor

✍ Scribed by Jon R. Gibbins; Rafael Kandiyoti

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 807 KB
• Volume: 70
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(91)90043-a

✦ Synopsis

A flowing-solvent liquefaction reactor has been used to examine the primary solubilization potential of a range of coals. The reactor configuration allows the suppression of secondary reactions by sweeping the heated zone with a continuous flow of solvent. The design of the system combines low thermal inertia and direct electrical resistance heating to provide closely controlled time-temperature ramping, and a variable preset holding time at the target temperature. Heating rates of O.l-15K s-' up to temperatures of 450°C and hold times of O-1600 s can be achieved. Data are reported for a range of European and US coals with elemental carbon contents ranging from 74 to 91%. The effect on conversion of reactor pressure, heating rate, temperature, holding time at temperature and solvent flow rate have been determined. In contrast with pyrolysis, results suggest that liquefaction reactivities are relatively insensitive to changes in the heating rate. Comparison with results from micro-bomb reactors has shown that the continuous solvent sweep allows the relatively intact removal of primary solubilization products from the reaction zone. Molecular mass distributions of solubilized products thus obtained have been found to increase with increasing carbon content of the substrate coal (up to -85%), and to decline with further increases up to 91% carbon content. In general, this reactor configuration appears to offer a promising avenue for analytically probing the more reactive structures of coals without interference from effects of secondary reactions.