Rational design of thermogravimetric experiments to determine intrinsic char gasification kinetics

M. A. Kibria, Pramod Sripada, Sankar Bhattacharya

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8 Citations (Scopus)

Abstract

The Boudouard reaction is an important heterogeneous reaction that takes place inside the gasifier during char gasification. To evaluate the gasification performance of solid fuels, it is important to know the intrinsic rate of the Boudouard reaction of that particular fuel. Incorrect determination of this rate results in error when used for modelling or gasifier scaling purposes. The thermo-gravimetric analyser (TGA) is an instrument that is widely used for gasification studies, particularly to explore the intrinsic gasification kinetics of coal or biomass char in a controlled environment. As in a real gasifier environment, several experimental parameters in TGA experiments can influence the intrinsic reactivity of the sample char; however, this is rarely discussed in the literature. It is essential to carefully differentiate the physical effects from the pure chemical reaction and to consider their interactions to obtain reliable kinetic parameters. No systematic experimental procedures to minimize the effects of the rate-influencing parameters during TGA experiments are available in the literature. This article presents an analysis for this purpose and demonstrates the variation in the gasification rate when the experimental conditions are not properly optimized. A mathematical model is also presented to explain the possible diffusional interactions with chemical kinetics during un-optimized TGA experiments.

Original languageEnglish
Pages (from-to)3023-3031
Number of pages9
JournalProceedings of the Combustion Institute
Volume37
Issue number3
DOIs
Publication statusPublished - 2019

Keywords

  • Gasification
  • Intrinsic-rate
  • TGA-model

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