Numerical Study of Hydrogen Inhibition of Char

Abstract

It has been known for a long time that hydrogen in the gas phase tend to inhibit gasification of char at low and intermediate temperatures. At higher temperatures, however, there are indications that hydrogen may speed up gasification. The mechanisms behind this effects are currently not understood. In this work, a newly developed detailed chemical kinetics model for char has been used in order to study the mechanisms behind the hydrogen inhibition and speed-up of char gasification. For conditions assumed in this work, the hydrogen inhibition is found for T < 2000K, while for T > 2000K the hydrogen in the gas phase speeds up the char conversion. By studying the species reaction rates together with the individual rate of every single reaction, the reasons for hydrogen influence on the char gasification are explained in this paper.