Evaluation and kinetic modelling of Greek lignites

Abstract

Two different types of Greek lignite were evaluated using the fast pyrolysis process in a fluidized bed reactor. The innovation in this experimental system is that the reactor effluent is connected on line with a flame ionization detector (FID) and a thermal conductivity (TC) detector for the continuous monitoring of total hydrocarbons and total gases, respectively. The total yield distribution of the various products was obtained as a function of pyrolysis temperature and lignite particle size. Two kinetic models for coal decomposition were also tested for the determination of appropriate kinetic parameters. From this work it can be concluded that: the gases produced from pyrolysis of Greek lignites are dominated by oxygen compounds (CO 2, CO); a number of hydrocarbons are also produced (C 1-C 6); the experimental results correlate well with the competing reaction model.