Numerical Simulation of Coal Gasification in a Circulating Fluidized Bed Gasifier

Abstract

This paper presents a 3D full-loop simulation of a circulating fluidized bed gasifier. The model is validated with experimental results from the literature. The validated model is thereupon used to compare Bubbling Fluidized Bed (BFB) and Circulating Fluidized Bed (CFB) gasifiers to highlight the effect of a change in fluidization regime from bubbling to fast fluidization on hydrodynamics, temperature and gas composition. Feed temperature as well as Air/Coal (A/C) and Steam/Coal (S/C) ratios are kept constant, whereas the velocity of the feed (Air-Steam) is increased so as to get into the fast fluidization regime. It was concluded that the flue gas from the CFB is richer in desired gases, i.e., CO and H 2 than that from BFB. H 2 remains approximately the same, CO 2 and CH 4 decreased to a negligible amount and CO approximately doubles when the regime is changed. In addition, tar content in the gas also decreases.

Coal Type, Temperature and Gasifiying Agent Effects on Low-Rank Coal Gasification Using CFD Method

“…Using CFD is very convenient, low cost and has accurate reproducibility [24]. For the gasification CFD model, it is usually built using the dimension or geometry of a lab-scale, pilot-scale or commercially available gasifier [25,26]. Compared to the experiment method, using CFD methods makes it much easier to change the input parameters like the feedstock properties, critical operating parameters such as temperature or pressure, gasifying agents and other parameters that influence the system performances.…”

Determination of parameters of the carbon­containing materials gasification process in the rotary kiln cooler drum

“…In [1][2][3][4][5][6], DPM or Euler-Lagrange formulations are used to determine the main parameters of the gasification process of solid combustible material, while the papers [7,[9][10][11][12][13] are based on the Euler-Granular Multiphase or Euler-Euler formulations, and in [8 both models are used.…”

“…The paper [10] is devoted to 3D modeling of a full cycle of a circulating fluidized bed gasifier based on the Euler-Granular Multiphase formulation. The kinetic model includes sixteen global heterogeneous and homogeneous chemical reactions.…”

“…In the analyzed works [1][2][3][4][5][6][7][8][9][10][11][12][13], specialized equipment for the gasification of solid carbon-containing materials is considered and no attention is paid to the modernization of existing industrial equipment in order to produce synthetic gas. Moreover, the kinetics of the chemical reactions of gasification, presented in these papers, differ significantly.…”

“…This, in turn, led to the appearance of a large number of developments of reactor equipment for gasification and research of gasification of solid fuels and biomass, in particular, by numerical methods of computational hydrodynamics [1][2][3][4][5][6][7][8][9][10][11][12][13]. These works do not consider the use of existing industrial furnace equipment for solid fuel gasification processes.…”