Contents lists available at ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel Review article A review of recent studies of the CFD modelling of coal gasifcation in entrained fow gasifers, covering devolatilization, gas-phase reactions, surface reactions, models and kinetics Jakub Mularski ⁎ , Halina Pawlak-Kruczek, Norbert Modlinski Department of Mechanics, Machines, Devices and Energy Processes, Faculty of Mechanical and Power Engineering, Wroclaw University of Science and Technology, Poland ARTICLE INFO Keywords: CFD Coal gasifcation Devolatilization Gas phase Char conversion Entrained fow reactor ABSTRACT The development and employment of comprehensive combustion/gasifcation models for the optimum selection of process conditions and gasifcation parameters, especially for entrained fow gasifers, are still in progress. Today many models are freely available in commercial CFD programs. Such tools have great potential as regards the design, optimization and retroftting of gasifers. The purpose of this study was to provide an overview of the CFD modelling of coal gasifcation, focusing on the models and kinetics of such processes as devolatilization, gas- phase reactions and surface reactions, which have been used in CFD simulations since the year 2000. It is well known that it is vital to correctly describe the devolatilization process in order to accurately estimate the sta- bilization and structure of the fame, and the fnal carbon conversion. On the basis of the gas-phase chemistry, one can correctly determine the reaction zone (fame) temperature and the local concentration of the gasifying agents. Surface reactions are considered to be most important in evaluating gasifer performance since they are the rate-limiting step of the process. This study reviews the latest papers on the CFD modelling of coal gasif- cation in entrained fow gasifers, focusing on the reliability of the approaches and the kinetics of devolatili- zation and the gas-phase and surface reactions incorporated into the model of the process. The most widely used models are highlighted and briefy described. The most widely applied kinetic parameters of the gas phase, devolatilization and char conversion are presented. 1. Introduction Gasifcation is defned as the thermochemical conversion ofa carbon-based solid fuel within diferent mediums, such as: air, O 2 ,H 2 O, CO 2 and H 2 , into a synthesis gas. Gasifcation is a chemical process consisting of many overlapping reactions in the gas and solid phases, which depend on the process parameters (temperature, pressure), the fuel properties, the type of the gasifcation agents and the stoichio- metry. The fnal products of gasifcation are a synthesis gas and ash/ slag (mineral residues). The gas consists mostly of CO and H 2 and trace amounts of light hydrocarbons, CO 2 and N-compounds. Gasifcation is an efcient way of raising the quality of the solid feedstock by con- verting it into a gas fuel. The gasifcation process can be divided into the following main sub- processes: a) Drying – moisture is released from the fuel and vaporized. Drying starts at a temperature which strongly depends on the pressure inside the reactor. For example, at the operating pressure of 1–60 bars [1] the boiling temperature of water ranges from 373 to 550 K [2]. At lower pressures, the boiling temperature will decrease ac- cordingly. b) Devolatilization – the thermal decomposition of the organic material in an oxygen-deprived atmosphere at elevated temperatures (600–900 K) [1,3]. It consists in the breaking of the labile bonds existing between the aromatic clusters in the feedstock. This results in the release of light gases (volatile matter) and high molecular- weight hydrocarbons (tar) and the formation of a carbonized re- sidue. c) Partial oxidation – the volatile products and some of the char react with O 2 to form CO 2 ,COandH 2 O, providing heat for the subsequent gasifcation reactions – an autothermal process. The amount of oxidant (either air or pure oxygen) which supports this process ranges from 25 to 40 per cent. d) Gasifcation/reduction- the remaining carbonized residue reacts with CO 2 and H 2 O to produce a gas with a high CO and H 2 content – https://doi.org/10.1016/j.fuel.2020.117620 Received 28 February 2019; Received in revised form 10 March 2020; Accepted 11 March 2020 ⁎ Corresponding author. Tel.: +48 71 320 21 81. E-mail address: jakub.mularski@pwr.edu.pl (J. Mularski). Fuel 271 (2020) 117620 Available online 27 March 2020 0016-2361/ © 2020 Elsevier Ltd. All rights reserved. T