Coal liquefaction modelling: 1. Development of a kinetic model

This is the first of three papers on modelling coal liquefaction processes. In this paper a kinetic model for the thermal dissolver of the Wilsonville integrated two stage liquefaction (ITSL) process was developed using a new reaction network to describe the liquefaction of Wyodak (Clovis Point) subbituminous coal. The coal was considered to consist of two differently reactive fractions and the liquefaction reactions were assumed to occur in two distinct stages. The first stage is an instantaneous dissolution of the most reactive coal fraction to lighter products. The second stage is a rate controlled conversion of the less reactive coal fraction and thermal resid. The kinetic model was developed using bench-scale data from the variable submergence temperature control (VaSTeC) autoclave programme conducted at the Wilsonville Advanced Coal Liquefaction Research and Development Facility. The model parameters were estimated using a non-linear multiresponse parameter estimation routine. An overall average absolute deviation of 9.57% and an overall error of 3.73%, between the predicted and observed autoclave outlet composition indicated a good fit of the model to the VaSTeC data.