Liquefaction Studies of Low-Rank Malaysian Coal Using High-Pressure High-Temperature Batch-Wise Reactor

Abstract

ABSTRACT Direct liquefaction of low-rank Malaysian coal from the Mukah Balingian (MB) area was successfully carried out in a 1000 ml high-temperature (360–450°C) high-pressure (4–13 MPa) batch-wise reactor system using tetralin as hydrogen donor solvent. The results indicated that the percent coal conversion obtained were in the range of 31–90%. At optimum conditions of 450°C and 4 MPa, the oil + gas, asphaltene and preasphaltene of the coal extract were 80%, 7%, and 2%, respectively. It was observed that heat plays an important role in comparison to pressure in contributing to high coal conversion, oil yield, and organic properties of the residues. The high coal conversion and oil yield correlate well with the high content of reactive macerals, i.e., vitrinite and exinite, in the coal. Other parameters that were also investigated include the effect of reaction time (0–120 min) and coal-to-solvent ratio. A high yield of asphaltene and preasphaltene was obtained at the longest reaction time (i.e., 120 min). Coal conversion and oil yield increase with increasing in coal-to-solvent ratio, with the optimal ratio being 1:5.