The prediction of pyrolysis products in grading Lignite pyrolysis process

摘要

Pyrolysis is the core unit of lower-rank coal upgrading and refining. A coal pyrolysis model which can be used to predict the product distribution is important to study the grading Lignite pyrolysis process. Based on mass balance in this paper, a pyrolysis model which combines prediction of volatile yields and component analysis of coal tar under different operating temperature is developed. The FG-DVC (Functional group-Depolymerization Vaporization Crosslinking) model is used to quantitatively predict the yields of pyrolysis char, light gases and coal tar. The Van Krevelen diagram which can provide the input parameters of the FG-DVC model by interpolation method is modified to cover more lower-rank coal. A non-linear programming (NLP) model is employed to analyze the component of coal tar, which includes phenols, aromatics, aliphatics, oxy-components and pitchs. The proximate analysis of char and ultimate analysis of coal tar are obtained based on the mass and element conservation of coal pyrolysis unit. The comparison between model prediction and experimental data validates this model both in total volatile yield and in tar yield.