Underground coal gasification modelling activities in Belgium

This paper summarizes recent modelling studies in Belgium. The models were developed within the framework of the two European Underground Coal Gasification (UCG) field trials at great depth: Thulin (Belgium), 1980--1987 and Alcorisa (Spain), 1992--1997 (in progress). UCG process modelling can be divided into two categories according to the degree of physicochemical description details: (1) models based on a macroscopic or ``global`` description of phenomena and (2) models based on a more detailed description of the mechanisms involved. In parallel to UCG process modelling activities, a production well model was developed on the same detailed description of the mechanisms involved.