Effect of Swirl on Gasification Characteristics in an Entrained-flow Coal Gasifier

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
Rongbin Li ◽  
Mingzhuang Xie ◽  
Hui Jin ◽  
Liejin Guo ◽  
Fengqin Liu
Keyword(s):  
Coal Gasification ◽  
Three Dimensional ◽  
Reaction Model ◽  
Gas Temperature ◽  
Swirl Number ◽  
Entrained Flow ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Product Composition ◽  
Gas Efficiency

AbstractThe three-dimensional (3-D) comprehensive mathematical model was developed to simulate the coal gasification process in an entrained flow gasifier with a swirl burner. The models employed or developed includes the coal devolatilization model, the char combustion and gasification model, the gas homogeneous reaction model, the random-trajectory model, gas turbulence model, and the P-1 radiation model. The solution of models was executed based on the computational fluid dynamics (CFD). By qualitatively comparing the results at different swirl number, the significant influences of swirl on characteristics of coal gasification such as flow distributions, gas temperature and product composition including hydrogen (H2), carbon monoxide (CO), etc., and on the performance of coal gasification such as averaged exit product composition, carbon conversion rate and cold gas efficiency, were in detail discussed. Especially, a proper swirl number (S ≤ 0.65) in favor of gasification was found for the investigated gasifier in this paper.

A Novel Coal Gasification System Through Thermochemical Regenerative Process of Syngas Sensible Heat to Enhance Cold Gas Efficiency

2017 ◽  
Author(s):  
Dandan Wang ◽  
Sheng Li ◽  
Lin Gao
Keyword(s):  
Energy Level ◽  
Coal Gasification ◽  
The Novel ◽  
Sensible Heat ◽  
Exergy Destruction ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Gasification Technology ◽  
Cold Gas

In this paper, a novel coal gasification technology used for Integrated Gasification Combined Cycle (IGCC) power plants is proposed, in which a regenerative unit is applied to recover syngas sensible heat to generate steam and then the high temperature steam is used to gasify coke from pyrolyzer. Through such a thermochemical regenerative unit, the sensible heat with lower energy level is upgraded into syngas chemical energy with higher energy level, and therefore a higher cold gas efficiency (CGE) is expected. The Aspen Plus Software is selected to simulate the novel coal gasification system. Then the exergy and Energy-Utilization Diagram (EUD) analyses are applied to disclose the plant performance enhancement mechanism. It reveals that 83.2% of syngas sensible heat can be recovered into steam agent and so the CGE is upgraded to 90%. And with the enhancement of CGE, the efficiency of an IGCC plant based on the novel gasification system can be as high as 51.82%, showing a significant improvement compared to 45.2% in a Texaco coal gasification based plant. At the same time, the exergy destruction of gasification process is reduced from 132.5MW to 98.4MW through thermochemical reactions. Lift of accepted energy level (Aea), and decrease of released energy level (Aed) and heat absorption (ΔH) contribute to the exergy destruction reduction in the gasification process. Additionally, since oxygen agent is no longer used in the IGCC, 34.5MW exergy loss in the air separation unit is avoided. Thereby the novel coal gasification technology proposed in this paper has a good thermodynamic performance and may provide a quite promising way for high efficient and clean coal utilization.

scholarly journals Catalytic Coal Gasification Process Simulation with Alkaline Organic Wastewater in a Fluidized Bed Reactor Using Aspen Plus

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1367 ◽  
Author(s):  
Xiao ◽  
Wang ◽  
Zheng ◽  
Qin ◽  
Zhou
Keyword(s):  
Process Simulation ◽  
Equivalence Ratio ◽  
Coal Gasification ◽  
Aspen Plus ◽  
Operating Conditions ◽  
Catalytic Gasification ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Organic Wastewater

A co-gasification process was proposed both for treating alkaline organic wastewater and to promote coal gasification by the alkaline substances in situ. A catalytic gasification model was developed by introducing a catalytic correction factor to describe the catalytic effects quantitatively. An integrated process simulation was carried out using Aspen Plus equipped with FORTRAN subroutines. The model was verified using the root mean square error between the simulation results and experimental data from the literature. Syngas composition, cold gas efficiency, and carbon conversion efficiency were analyzed with respect to different operating conditions (reaction temperature, steam/coal ratio, and equivalence ratio). The optimal conditions are summarized based on a self-sufficient system by using sensitivity analysis: Gasification temperature of 700 °C, steam/coal ratio = 1.0, and equivalence ratio = 0.4.

A parametric study on coal gasification for the production of syngas

2012 ◽  
Vol 66 (7) ◽  
Author(s):  
Afsin Gungor ◽  
Murat Ozbayoglu ◽  
Cosku Kasnakoglu ◽  
Atilla Biyikoglu ◽  
Bekir Uysal
Keyword(s):  
Parametric Study ◽  
Coal Gasification ◽  
Steam Gasification ◽  
Heating Value ◽  
Fuel Ratio ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Reactor Temperature ◽  
Gas Efficiency ◽  
Optimum Working

AbstractIn this parametric study, the effects of coal and oxidiser type, air-to-fuel ratio, steam-to-fuel ratio, reactor temperature, and pressure on H2 and CO amounts at the gasifier output, H2/CO, and higher heating value of the syngas produced have been calculated using a coal gasification model. Model simulations have been performed to identify the optimum values which are assumed to be 100 % for both cold gas efficiency and carbon conversion efficiency in the gasification process. From this study, it may be observed that the moisture content of the coal type is of crucial importance for the air gasification process; the O2 content of similar coals (taking into consideration the moisture and H2 content) is of significant importance for the air gasification process. When compared with air gasification, air-steam gasification becomes a more effective coal gasification method. The optimum working condition for air-steam gasification is to carry out the process at one atmosphere. High gasifier temperatures are not needed for the air-steam gasification of coal.

Study on Gasification Characteristics of Petroleum Asphalt in a Two-Stage Gasifier

2014 ◽  
Vol 953-954 ◽  
pp. 1673-1677
Author(s):  
Guang Yu Li ◽  
Shi Sen Xu ◽  
Jun Cang Xia ◽  
Yong Qiang Ren
Keyword(s):  
Bituminous Coal ◽  
Heterogeneous Reaction ◽  
Reaction Model ◽  
Utilization Rate ◽  
Two Stage ◽  
Petroleum Asphalt ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Cold Gas

The gasification performance of petroleum asphalt in a two-stage gasifier was investigated through experiments and simulations. The analysis results of asphalt samples show that the asphalt has characteristics of high volatile content, high calorific value, and low ash content. Coal pyrolysis model, gas-solid heterogeneous reaction model, gas homogeneous reaction model and Gibbs free energy minimization method were employed to build the two-stage entrained flow gasification model and simulate the asphalt gasification process using Aspen Plus software. The results indicate that the cold gas efficiency of asphalt is 3% higher than that of bituminous coal, while the consumption of coal and oxygen is 40% lower than that of bituminous coal. The gasification performance of asphalt is superior to that of coal. In addition, the cold gas efficiency of asphalt can be increased by about 3% when the two-stage gasification process is employed. The utilization rate of coal in the two-stage gasifier is much higher than that in traditional one-stage gasifier.

scholarly journals Mathematical modelling of the oxyfuel gasification of pulverized coal fuel

2020 ◽  
Vol 209 ◽  
pp. 03011
Author(s):  
Igor Donskoy
Keyword(s):  
Mathematical Modelling ◽  
Coal Gasification ◽  
Stoichiometric Ratio ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Coal Fuel ◽  
Pulverized Coal Fuel ◽  
Optimal Values ◽  
Gas Efficiency ◽  
Cold Gas

In this work, we studied the efficiency of the coal gasification process under oxyfuel conditions. Using mathematical modelling one-dimensional stationary statement, the optimal parameters of coal processing were determined, air and oxyfuel conditions are compared. The calculated dependences of the characteristics of the gasification process on the stoichiometric ratio at different initial temperatures are constructed. The optimal values of oxygen stoichiometric ratio and the maximum values of cold gas efficiency in the selected range of parameters are determined. The contribution of the thermophysical and reactive properties of the gasification agent to the change in the cold gas efficiency is estimated.

scholarly journals CO-GASIFICATION OF COAL AND EMPTY FRUIT BUNCH (EFB) IN AN ENTRAINED FLOW GASIFICATION PROCESS

2017 ◽  
Vol 2 (1) ◽  
pp. 37-46
Author(s):  
Wan Muhamad Syafiq Wan Ismail ◽  
Ruwaida Abdul Rasid
Keyword(s):  
Alternative Energy ◽  
Process Conditions ◽  
Empty Fruit Bunch ◽  
Mass Ratio ◽  
Entrained Flow ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Production Of Hydrogen ◽  
Carbon Dioxide Co2 ◽  
Gas Efficiency

In Malaysia, empty fruit bunch (EFB) is one of the major biomass source from the palm oil industry. It is an environmental friendly, renewable and sustainable source of energy, which may be used to generate electricity and other forms of energy. EFB may be converted into synthesis gas (syngas) through the gasification process, or mixed with coal through the co-gasification process. Raw EFB usually consists of high moisture content and low energy density compared to coal. Having a mixture of biomass and coal is one of the method to increase the efficiency of the biomass gasification process. Hence, it is the objective of this work to investigate the co-gasification of coal and EFB at various process conditions, whereby, an entrained flow gasifier was used to investigate the effect of the gasification temperature in the range of 700°C – 900°C, for various coal-EFB mixtures on the syngas composition. The produced gas was collected and quantified using gas chromatography. It was found that when the mass ratio of coal to EFB was increased, the production of hydrogen (H2), carbon monoxide (CO) and carbon dioxide (CO2) also increases. Besides that, the carbon conversion and the higher heating value (HHV) of the gas products also increases with increasing in mass ratio of coal-EFB mixtures. The highest cold gas efficiency (CGE) recorded for coal mixture is 2.72 MJ/m3. Thus, this shows the potential in co-gasification for producing alternative energy to the conventional fossil fuel resources that is depleting.

scholarly journals Investigation of the Coal Gasification Process Under Various Operating Conditions Inside a Two-Stage Entrained Flow Gasifier

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Armin Silaen ◽  
Ting Wang
Keyword(s):  
Coal Gasification ◽  
Operating Conditions ◽  
Coal Slurry ◽  
Two Stage ◽  
Heating Value ◽  
Fuel Distribution ◽  
Entrained Flow ◽  
One Stage ◽  
Gasification Process ◽  
Entrained Flow Gasifier

Numerical simulations of the coal gasification process inside a generic 2-stage entrained-flow gasifier fed with Indonesian coal at approximately 2000 metric ton/day are carried out. The 3D Navier–Stokes equations and eight species transport equations are solved with three heterogeneous global reactions, three homogeneous reactions, and two-step thermal cracking equation of volatiles. The chemical percolation devolatilization (CPD) model is used for the devolatilization process. This study is conducted to investigate the effects of different operation parameters on the gasification process including coal mixture (dry versus slurry), oxidant (oxygen-blown versus air-blown), and different coal distribution between two stages. In the two-stage coal-slurry feed operation, the dominant reactions are intense char combustion in the first stage and enhanced gasification reactions in the second stage. The gas temperature in the first stage for the dry-fed case is about 800 K higher than the slurry-fed case. This calls for attention of additional refractory maintenance in the dry-fed case. One-stage operation yields higher H2, CO and CH4 combined than if a two-stage operation is used, but with a lower syngas heating value. The higher heating value (HHV) of syngas for the one-stage operation is 7.68 MJ/kg, compared with 8.24 MJ/kg for two-stage operation with 75%–25% fuel distribution and 9.03 MJ/kg for two-stage operation with 50%–50% fuel distribution. Carbon conversion efficiency of the air-blown case is 77.3%, which is much lower than that of the oxygen-blown case (99.4%). The syngas heating value for the air-blown case is 4.40 MJ/kg, which is almost half of the heating value of the oxygen-blown case (8.24 MJ/kg).

Multi-Criteria Evaluation of Coal Properties in Terms of Gasification

2014 ◽  
Vol 59 (3) ◽  
pp. 677-690 ◽  
Author(s):  
Jolanta Marciniak-Kowalska ◽  
Tomasz Niedoba ◽  
Agnieszka Surowiak ◽  
Tadeusz Tumidajski
Keyword(s):  
Particle Size ◽  
Coal Gasification ◽  
Three Dimensional ◽  
Point Of View ◽  
Gasification Process ◽  
Multi Criteria Evaluation ◽  
Depth Analysis ◽  
Coal Properties ◽  
Induced Changes ◽  
Dimensional Surface

Abstract This paper presents a comparative analysis of two types of coal taken from the ZG Janina and ZG Wieczorek coalmines. The aim of this study has been to analyze the suitability of the coal in the context of the gasification process. The types of coal vary considerably in terms of their characteristics. Each of them was subjected to treatment in a ten-ringed annular jig. A particle size of 0-18 mm constituted the feed. The separated coal was divided into five layers, each of them containing material from two additional annular jigs. Analysis of their characteristics was carried out for each of the five layers and for both types of coal obtained, taking into account both their physicochemical properties as well as chemical ones. Each of these characteristics was then presented in three-dimensional surface diagrams, where the ordinate (or Y-axis) and abscissa (X-axis) was the particle size and height in which the material ended up in the jig (expressed as a percentage of the total height of the device). On the basis of observations, it was found that the types of coal have different potential for gasification, although both types are within the limits specified on the basis of previous studies. A correlation analysis between particle size and remaining characteristics of coal was carried out for each of the layers, allowing to determine which of the studied characteristics induced changes significant from the point of view of the coal gasification process. The entire research and observation was supported by conclusions and findings, which shall form the basis for further, in-depth analysis of coal.

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.

The Effect of Biomass Contents with Heavy Metal on Gasification Efficiency during Fluidized Bed Gasification Process

2012 ◽  
Vol 512-515 ◽  
pp. 575-578
Author(s):  
Hsien Chen ◽  
Chiou Liang Lin ◽  
Wun Yue Zeng ◽  
Zi Bin Xu
Keyword(s):  
H2 Production ◽  
Heating Value ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Zn Concentration ◽  
Lower Heating Value ◽  
Gasification Efficiency ◽  
Waste Gasification ◽  
Gas Efficiency ◽  
Cu And Zn

Catalysis was used to increase the H2 production, syngas heating value, enhanced carbon conversion efficiency and cold gas efficiency during gasification. Due to Cu and Zn were abundant in waste according to previous researches, this research discussed the effect of Cu and Zn on artificial waste gasification. The syngas composition and total lower heating value (LHV) were determined in this study. The results showed that the existence of Cu and Zn increased production of H2 and CO. However, the production of CH4 and CO2 decreased. At same time, total LHV was also increased. Additionally, the different Cu concentration affected gas composition and LHV, but the effect of Zn concentration was not significant.

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