Numerical study on the coal gasification characteristics in an entrained flow coal gasifier

Fuel ◽  
2001 ◽  
Vol 80 (15) ◽  
pp. 2193-2201 ◽  
Author(s):  
Y.C. Choi ◽  
X.Y. Li ◽  
T.J. Park ◽  
J.H. Kim ◽  
J.G. Lee
Keyword(s):  
Coal Gasification ◽  
Numerical Study ◽  
Entrained Flow ◽  
Coal Gasifier

Numerical Study of Coal Gasification Using Eulerian-Eulerian Multiphase Model

2007 ◽  
Author(s):  
Shaoping Shi ◽  
Christopher Guenther ◽  
Stefano Orsino
Keyword(s):  
Gas Phase ◽  
Large Scale ◽  
Coal Gasification ◽  
Solid Phase ◽  
Numerical Study ◽  
Three Dimensional ◽  
Phase Method ◽  
Multiphase Model ◽  
Measured Temperature ◽  
Entrained Flow

Gasification converts the carbon-containing material into a synthesis gas (syngas) which can be used as a fuel to generate electricity or used as a basic chemical building block for a large number of uses in the petrochemical and refining industries. Based on the mode of conveyance of the fuel and the gasifying medium, gasification can be classified into fixed or moving bed, fluidized bed, and entrained flow reactors. Entrained flow gasifiers normally feature dilute flow with small particle size and can be successfully modeled with the Discrete Phase Method (DPM). For the other types, the Eulerian-Eulerian (E-E) or the so called two-fluid multiphase model is a more appropriate approach. The E-E model treats the solid phase as a distinct interpenetrating granular “fluid” and it is the most general-purposed multi-fluid model. This approach provides transient, three-dimensional, detailed information inside the reactor which would otherwise be unobtainable through experiments due to the large scale, high pressure and/or temperature. In this paper, a transient, three-dimensional model of the Power Systems Development Facility (PSDF) transport gasifier will be presented to illustrate how Computational Fluid Dynamics (CFD) can be used for large-scale complicated geometry with detailed physics and chemistry. In the model, eleven species are included in the gas phase while four pseudo-species are assumed in the solid phase. A total of sixteen reactions, both homogeneous (involving only gas phase species) and heterogeneous (involving species in both gas and solid phases), are used to model the coal gasification chemistry. Computational results have been validated against PSDF experimental data from lignite to bituminous coals under both air and oxygen blown conditions. The PSDF gasifier geometry was meshed with about 70,000, hexahedra-dominated cells. A total of six cases with different coal, feed gas, and/or operation conditions have been performed. The predicted and measured temperature profiles along the gasifier and gas compositions at the outlet agreed fairly well.

Design and Testing of a High Pressure and High Temperature, Optically Accessible, Entrained Flow Coal Gasifier

2011 ◽  
Author(s):  
Indraneel Sircar ◽  
Rohan Gejji ◽  
Anup Sane ◽  
David Blunck ◽  
Scott Meyer ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Tunable Diode Laser ◽  
Thermodynamic Efficiency ◽  
Entrained Flow ◽  
Laser Absorption ◽  
Coal Gasifier ◽  
Powder Feeder ◽  
Major Species ◽  
Gasification Reaction ◽  
Design And Testing

Improved understanding of coal gasification chemical kinetics is needed to increase thermodynamic efficiency and to reduce undesirable CO2 emissions. This work describes an optically-accessible entrained-flow coal gasifier designed and built to allow measurements of the major species at various stages of the chemical reactions. The 2-meter tall gasifier consists of five subsystems: the optical diagnostics, steam generator, coal feeder, external heaters, and gas sampling and analysis. A stoichiometric H2-O2 flame generates superheated steam, the gasifying agent, which reacts with pulverized coal fed from a variable feed-rate pressurized powder feeder. To sustain the endothermic coal gasification reaction, radiant heaters provide 15 kW of external heating. Diagnostics to determine the major species concentrations consist of tunable diode laser absorption spectroscopy (TDLAS) measurements within the reactor vessel assembly and analysis of dry product gases using a gas chromatograph.

scholarly journals Development of a 2T/D pressurized two-stage entrained flow coal gasifier. 1st, Report, Characteristics of coal gasification.

1991 ◽  
Vol 57 (535) ◽  
pp. 790-795 ◽  
Author(s):  
Jun INUMARU ◽  
Saburo HARA ◽  
Masami ASHIZAWA ◽  
Yuichi KOBAYASHI ◽  
Teruhide HAMAMATSU ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Two Stage ◽  
Entrained Flow ◽  
Coal Gasifier

Numerical Simulation of Coal Ash Particle Behavior in Entrained Flow Coal Gasifier

2003 ◽  
Author(s):  
Hiroaki Watanabe ◽  
Kazuyoshi Ichikawa ◽  
Maromu Otaka ◽  
Jun Inumaru
Keyword(s):  
Numerical Simulation ◽  
Gas Phase ◽  
Coal Gasification ◽  
Current Model ◽  
Electric Power Industry ◽  
Central Research ◽  
Ash Deposition ◽  
Entrained Flow ◽  
Coal Gasifier ◽  
Coal Particles

The objective of this study is to develop an evaluation tool for a design and performance of a coal gasifier by a numerical simulation technique. In the present paper, a gas-particle two phase reacting flow calculation is carried out for a prediction of phenomena in an entrained flow coal gasifier due to coal and ash particles behavior, such as ash deposition on the wall. A transportation of the coal particles is modeled via a Lagrangian manner. The ash particle adhesion on the wall of the gasifier is discriminated by an empirical ash adhesion model based on a liquid phase fraction concept in the ash particle. The gas phase properties are calculated by three dimensional time-mean Eulerian conservation equations. The turbulent flow field is determined by the k-ε two equations model. Radiative heat transfer is calculated by the discrete transfer radiation method. Coal gasification reaction model is composed of three chemical processes in the current model: a pyrolysis, a char gasification and gas phase reactions. 2 tons/day (t/d) air-blown pressurized entrained flow coal gasifier, which has been constructed and operated by Central Research Institute of Electric Power Industry (CRIEPI) was targetted. As a result, a relationship between an operating condition (air ratio) of the gasifier and the gasifier performance is presented. The trend of the ash deposition on the gasifier inner wall is also presented. Comparison between the computational and the experimental results shows that the most feature of the gasifier performance and the profile of the ash deposition have been captured by the present model. It was confirmed that the numerical simulation approach is very useful for the assessment of gasifier performance and operation support.

Numerical Study of Effects of Operation Condition for Oxygen Blown Coal Gasifier in Oxy-Fuel IGCC

2017 ◽  
Author(s):  
Kenji Tanno ◽  
Ahn Seongyool ◽  
Hiroaki Watanabe
Keyword(s):  
Coal Gasification ◽  
Feeding Rate ◽  
Numerical Study ◽  
Thermal Power ◽  
Water Gas Shift ◽  
Co2 Injection ◽  
Water Gas Shift Reaction ◽  
Coal Gasifier ◽  
Shift Reaction ◽  
Water Gas

In order to reduce CO2 emission from thermal power stations with keeping high thermal efficiency, a new concept of IGCC system, namely oxy-fuel IGCC, has been recently proposed. Hence CO2 is recycled in the system, the effect of CO2 recycle on each equipments should be clarified. In this study, the effect of recycled CO2 injection on coal gasifier performance was investigated by means of three-dimensional RANS-based numerical simulation. For estimating of coal gasifier performance, coal gasification and water-gas shift reaction are key phenomena. Therefore, the partially active site sharing coal gasification model and detailed chemistry of water-gas shift reaction model were implemented. Calculated gasifier was a commercial scale entrained flow coal gasifier whose coal feeding rate is 70 tons per hour. The gasifier consists of a lower combustor part and an upper reductor part. The effect of coal feeding rate into the reductor, R/T, was investigated. The results show that temperature in the combustor decreases with decreasing R/T. In the lower R/T condition, hence air ratio in the combustor decreases, the reducing atmosphere becomes stronger. As a result, coal gasification which is endothermic reaction in the combustor is promoted. Although coal gasification is occurred in the reductor in higher R/T condition, total coal gasification rate is not so promoted compared with lower R/T condition. Due to the above mechanism, the gasification performance becomes higher with decreasing R/T. The results obtained in this study indicate that it is important that how much the higher gasification reactivity in a gasifier is exploited by optimizing local heat balance.

Modeling and simulation of coal gasification on an entrained flow coal gasifier with a recycled CO2 injection

Fuel ◽  
2015 ◽  
Vol 142 ◽  
pp. 250-259 ◽  
Author(s):  
Hiroaki Watanabe ◽  
Kenji Tanno ◽  
Hiroki Umetsu ◽  
Satoshi Umemoto
Keyword(s):  
Modeling And Simulation ◽  
Coal Gasification ◽  
Co2 Injection ◽  
Entrained Flow ◽  
Coal Gasifier
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