Kinetic Analysis of Tar’s Separation from Lump Coal

Abstract

The tar separated out from the lump coal has an important effect on COREX process. In this paper, a designed experimental method is used to study the kinetics of tar’s separation from lump coal. The weight percent gain of the tar was defined as the tar’s separation conversion using the weight-loss ratio in TGA for reference, and then the isothermal and non-isothermal kinetic models were used to analyze the dynamics mechanism of tar’s generation. Based on the characteristic of tar’s generation, we suppose that the shrinking core model is suited to the early heating process of lump coal, and the mid-term and later stage of tar’s generation are respectively controlled by the coal pyrolysis and the spread of the tar molecule. Thus, the equation of non-isothermal unreacted core model, the first order reaction model and the Anti-Jander diffusion equation are respectively established to describe the tar’s generation. The fitting results of these three models showed a good linear dependence relation illustrating that the experimental method and the hypothetical models in this paper are reliable. What’s more, a way is provided to study the tar’s or other substances’ dynamic separation through the experiment method.