Chemical Process Modelling of Underground Coal Gasification and Evaluation of Produced Gas Quality for End Use

Abstract

The chemical process at the heart of Underground Coal Gasification (UCG) is the engineered injection of a blend of gasification (normally O2, air, H2O) agents into the coal resource. Established surface gasifier chemical modelling principles are adapted for modelling UCG processes. Model configurations developed in Aspen Plus are used to simulate the Linked Vertical Wells and the Controlled Retractable Injection Point gasifier layouts. Sensitivity analyses were conducted to investigate the effect of operational parameters and performance indicators. Model outputs were validated using reported UCG trial results. The gasification designs developed could form the basis for developing an integrated UCG model.