2002 Volume 81 Issue 5 Pages 337-344
Progress of coal liquefaction was observed and analyzed for Tanito Harum coal heated in the preheater of 1t/d Process Supporting Unit (PSU) for the NEDOL Process. Direct measurement of the slurry temperature and sampling of the preheater effluents were conducted to obtain data necessary for the analysis. Interest has been focussed on preparation of basic design data on initial-stage coal liquefaction as well as product distributions at the preheater outlet which could be utilized as the inlet boundary conditions for the first-stage liquefaction reactor.
The results showed that decomposition of tetrahydrofuran insoluble component rapidly proceeds within the preheater. The actual residence time of coal slurry in the preheater was determined from the time required for complete replacement of the recycling solvent with the coal slurry, which was detected as variation of the pressure drop through the preheater along with the replacement. The residence time was utilized to estimate the slurry temperature distribution along the preheater and the progress of liquefaction. As a result, it was indicated that the rapid decrease in IOM (Insoluble Organic Matter: THFI) is reasonably explained by assuming coal to consist of reactive and less-reactive components.