The Influence of Hydrodynamics on the NEDOL Coal Liquefaction Reaction

Abstract

In NEDOL's 1-ton-per-day process supporting unit, a plant designed to provide support data for the NEDOL coal liquefaction process which has been developed up to the 150-tons-per-day scale, the hydrodynamic behavior of coal slurry in the coal liquefaction reactors was observed using neutron absorption tracer equipment. The results clarified that the three reactors installed in series in the plant performed in a complete mixing mode providing sufficient contact between the liquid and hydrogen gas. It was also found that the increase of the gas feed rate resulted in the increase of liquid-phase mean residence time (MRT). This increase of MRT resulted in a decrease in the coal liquefaction residue yield and an increase in the coal liquefaction oil yield. However, the increase of the MRT did not improve the naphtha (C 4 -493 K fraction) yield because of vaporization of the light oil (493-623 K fraction) in the coal liquefaction reactors.

Improvement of Product Quality and Yield on the NEDOL Coal Liquefaction Process

“…The present authors reported that RTD curves 14 in the NEDOL process overlapped those of theoretical CSTR through experiments under a wide range of reaction conditions. However, the second and third coal liquefaction reactors in run 3, in which the lighter fraction was rich in the recycle solvent, was not in a complete mixing state and the effects of this incomplete mixing state on the coal liquefaction reaction were a concern.…”

Modeling transport phenomena and reactions in a pilot slurry airlift loop reactor for direct coal liquefaction

“…It has been reported that the hydrodynamic behavior in a coal liquefaction reactor affected the product quality and conversion (Wasaka et al, 2003). It is particularly important to understand the relationship between the reaction behavior and the hydrodynamics in an IALR for scale-up of a coal liquefaction reactor.…”