A Comparison of Coal Liquefaction Characteristics in a Continuous Stirred Tank Reactor with that in a Batch Micro-Atoclave

Abstract

Liquefaction of Auefaction of Akabira coal by sufficient amount of tetralin was conducted in both a 5, 000 cm³ continuous stirred tank reactor and a 27 cm³ batch microautoclave reactor at 673 K and 5.4 MPa. The batch reactor was operated with different heating rates ranging from 4 K/min to 150 K/min so that the effects of the heating rate on the conversion of coal to benzene solubles could be evaluated. The residence time distribution of coal particles in the continuous reactor was also measured at room temperature.
In the batch reactor, change of the conversion with time differed appreciably depending on the heating rate even if other operating variables were same. With increasing heating rates the conversion during the heating period decreased while the conversion level attained at the final stage of the reaction increased. Using the kinetic data together with the observed residence time distribution of the coal particles, the conversions in the continuous reactor were predicted. From a comparison between the predicted and observed conversions it was concluded that conversion in a continuous reactor can be predicted on the basis of kinetic data obtained in a batch reactor with the same heating rate as in the continuous one.