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Research Papers: Fuel Combustion

Exergy Destruction Mechanism of Coal Gasification by Combining the Kinetic Method and the Energy Utilization Diagram

[+] Author and Article Information
Handong Wu

Institute of Engineering Thermophysics,
Chinese Academy of Sciences,
University of Chinese Academy of Sciences,
No. 11 North Fourth Ring Road West,
Haidian District,
Beijing 100190, China
e-mail: wuhandong@iet.cn

Sheng Li

Institute of Engineering Thermophysics,
Chinese Academy of Sciences,
University of Chinese Academy of Sciences,
No. 11 North Fourth Ring Road West,
Haidian District,
Beijing 100190, China
e-mail: lisheng@iet.cn

Lin Gao

Institute of Engineering Thermophysics,
Chinese Academy of Science,
University of Chinese Academy of Sciences,
No. 11 North Fourth Ring Road West,
Haidian District,
Beijing 100190, China
e-mail: gaolin@iet.cn

1Corresponding author.

Contributed by the Advanced Energy Systems Division of ASME for publication in the JOURNAL OF ENERGY RESOURCES TECHNOLOGY. Manuscript received September 26, 2016; final manuscript received May 1, 2017; published online June 15, 2017. Assoc. Editor: Antonio J. Bula.

J. Energy Resour. Technol 139(6), 062201 (Jun 15, 2017) (9 pages) Paper No: JERT-16-1386; doi: 10.1115/1.4036957 History: Received September 26, 2016; Revised May 01, 2017

Gasification is the core unit of coal-based production systems and is also the site where one of the largest exergy destruction occurs. This paper reveals the exergy destruction mechanism of carbon gasification through a combined analysis of the kinetic method and the energy utilization diagram (EUD). Instead of a lumped exergy destruction using the traditional “black-box” and other models, the role of each reaction in carbon gasification is revealed. The results show that the exergy destruction caused by chemical reactions accounts for 86.3% of the entire carbon gasification process. Furthermore, approximately 90.3% of exergy destruction of chemical reactions is caused by the exothermal carbon partial oxidation reaction (reaction 1), 6.0% is caused by the carbon dioxide gasification reaction (reaction 2), 2.4% is caused by the steam gasification reaction (reaction 3), and 1.3% is caused by other reactions under the base condition. With increasing O2 content α and decreasing steam content β, the proportion of exergy destruction from reaction 1 decreases due to the higher gasification temperature (a higher energy level of energy acceptor in EUD), while the proportions of other reactions increase. This shows that the chemical efficiency is optimal when the extent of reactions 1 and 3 is equal and the shift reaction extent approaches zero at the same time.

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References

Gao, L. , Jin, H. G. , Liu, Z. L. , and Zheng, D. X. , 2004, “ Exergy Analysis of Coal-Based Polygeneration System for Power and Chemical Production,” Energy, 29(12), pp. 2359–2371. [CrossRef]
Liu, G. J. , Li, Z. , Huang, H. , and Ni, W. D. , 2008, “ Thermodynamic Analysis of the Coal Gasification Process,” J. Tsinghua Univ. (Sci. Technol.), 48(5), pp. 844–847.
Govind, R. , and Shah, J. , 1984, “ Modeling and Simulation of an Entrained Flow Coal Gasifier,” AIChE J., 30(1), pp. 79–92. [CrossRef]
Wu, X. C. , Wang, Q. H. , Luo, Z. Y. , Fang, M. X. , and Ceb, K. , 2004, “ Modelling on Effects of Operation Parameters on Entrained Flow Coal Gasification (I): Model Establishment and Validation,” J. Zhejiang Univ. (Eng. Sci.), 38(10), pp. 1361–1365.
Reyes, S. , and Jensen, K. F. , 1986, “ Percolation Concepts in Modelling of Gas-Solid Reactions—I: Application to Char Gasification in the Kinetic Regime,” Chem. Eng. Sci., 41(2), pp. 333–343. [CrossRef]
Zhou, W. , Luo, Y. H. , Wu, G. J. , and Deng, J. , 2009, “ Modeling the Gasification Characteristics of Char Particle Under Kinetics Control,” J. Fuel Chem. Technol., 37(1), pp. 31–35.
Qi, X. , Guo, X. , Xue, L. , and Zheng, C. , 2014, “ Effect of Iron on Shenfu Coal Char Structure and Its Influence on Gasification Reactivity,” J. Anal. Appl. Pyrolysis, 110, pp. 401–407. [CrossRef]
Li, M. , Brouwer, J. , Rao, A. D. , and Samuelsen, G. S. , 2011, “ Application of a Detailed Dimensional Solid Oxide Fuel Cell Model in Integrated Gasification Fuel Cell System Design and Analysis,” J. Power Sources, 196(14), pp. 5903–5912. [CrossRef]
Xiang, Y. Q. , and Hedden, K. , 1986, “ Theoretical Calculation of Thermodynamic Equilibrium Compositions in Coal Gasification Process,” Gas Heat, (1), pp. 4–10.
Acharya, B. , Dutta, A. , and Basu, P. , 2010, “ An Investigation Into Steam Gasification of Biomass for Hydrogen Enriched Gas Production in Presence of CaO,” Int. J. Hydrogen Energy, 35(4), pp. 1582–1589. [CrossRef]
Dervisoglu, M. , and Hortaçsu, Ö. , 1998, “ An Experimental Study of Coal Gasification,” Energy, 23(12), pp. 1073–1076. [CrossRef]
Li, X. , Grace, J. R. , Watkinson, A. P. , Lim, C. J. , and Ergüdenler, A. , 2001, “ Equilibrium Modeling of Gasification: A Free Energy Minimization Approach and Its Application to a Circulating Fluidized Bed Coal Gasifier,” Fuel, 80(2), pp. 195–207. [CrossRef]
Shabbar, S. , and Janajreh, I. , 2013, “ Thermodynamic Equilibrium Analysis of Coal Gasification Using Gibbs Energy Minimization Method,” Energy Convers. Manage., 65, pp. 755–763. [CrossRef]
Yi, Q. , Feng, J. , and Li, W. Y. , 2012, “ Optimization and Efficiency Analysis of Polygeneration System With Coke-Oven Gas and Coal Gasified Gas by Aspen Plus,” Fuel, 96, pp. 131–140. [CrossRef]
Zheng, L. , and Furimsky, E. , 2003, “ ASPEN Simulation of Cogeneration Plants,” Energy Convers. Manage., 44(11), pp. 1845–1851. [CrossRef]
Prins, M. J. , and Ptasinski, K. , 2005, “ Energy and Exergy Analyses of the Oxidation and Gasification of Carbon,” Energy, 30(7), pp. 982–1002. [CrossRef]
Zheng, D. X. , Moritsuka, H. , and Ishida, M. , 1986, “ Graphic Exergy Analysis for Coal Gasification—Combined Power Cycle Based on the Energy Utilization Diagram,” Fuel Process. Technol., 13(2), pp. 125–138. [CrossRef]
Wang, Y. , Zhu, S. , Gao, M. , Yang, Z. , Yan, L. , Bai, Y. , and Li, F. , 2016, “ A Study of Char Gasification in H2O and CO2 Mixtures: Role of Inherent Minerals in the Coal,” Fuel Process. Technol., 141(Part 1), pp. 9–15. [CrossRef]
Mühlen, H. J. , Heinrich, V . H. K. , and Harald, J. , 1985, “ Kinetic Studies of Steam Gasification of Char in the Presence of H2, CO2 and CO,” Fuel, 64(7), pp. 944–949. [CrossRef]
Ross, D. P. , Yan, H. M. , and Zhang, D. K. , 2004, “ Modelling of a Laboratory-Scale Bubbling Fluidised-Bed Gasifier With Feeds of Both Char and Propane,” Fuel, 83(14), pp. 1979–1990. [CrossRef]
Watanabe, H. , and Otaka, M. , 2006, “ Numerical Simulation of Coal Gasification in Entrained Flow Coal Gasifier,” Fuel, 85(12), pp. 1935–1943. [CrossRef]
Kaya, E. , and Köksal, M. , 2016, “ Investigation of the Predicting Ability of Single-Phase Chemical Equilibrium Modeling Applied to Circulating Fluidized Bed Coal Gasification,” ASME J. Energy Resour. Technol., 138(3), p. 032203. [CrossRef]
Lee, J. M. , Kim, Y. J. , Lee, W. J. , and Kim, S. D. , 1998, “ Coal-Gasification Kinetics Derived From Pyrolysis in a Fluidized-Bed Reactor,” Energy, 23(6), pp. 475–488. [CrossRef]
Ishida, M. , and Kawamura, K. , 1982, “ Energy and Exergy Analysis of a Chemical Process System With Distributed Parameters Based on the Enthalpy-Direction Factor Diagram,” Ind. Eng. Chem. Process Des. Dev., 21(4), pp. 690–695. [CrossRef]
Ishida, M. , and Zheng, D. , 1986, “ Graphic Exergy Analysis of Chemical Process Systems by a Graphic Simulator, GSCHEMER,” Comput. Chem. Eng., 10(6), pp. 525–532. [CrossRef]
Zheng, D. , and Cao, W. , 2007, “ Retrofitting for DME Process by Energy-Flow Framework Diagram,” Chem. Eng. Process.: Process Intensif., 46(1), pp. 2–9. [CrossRef]
Halama, S. , and Spliethoff, H. , 2016, “ Reaction Kinetics of Pressurized Entrained Flow Coal Gasification: Computational Fluid Dynamics Simulation of a 5 MW Siemens Test Gasifier,” ASME J. Energy Resour. Technol., 138(4), p. 042204. [CrossRef]
Chejne, F. , and Hernandez, J. P. , 2002, “ Modelling and Simulation of Coal Gasification Process in Fluidised Bed,” Fuel, 81(13), pp. 1687–1702. [CrossRef]
Yu, L. , Lu, J. , Zhang, X. P. , and Zhang, S. J. , 2007, “ Numerical Simulation of the Bubbling Fluidized Bed Coal Gasification by the Kinetic Theory of Granular Flow (KTGF),” Fuel, 86(5), pp. 722–734. [CrossRef]
Mendes, A. , Dollet, A. , Ablitzer, C. , Perrais, C. , and Flamant, G. , 2008, “ Numerical Simulation of Reactive Transfers in Spouted Beds at High Temperature: Application to Coal Gasification,” J. Anal. Appl. Pyrol., 82(1), pp. 117–128. [CrossRef]
Irfan, M. F. , Usman, M. R. , and Kusakabe, K. , 2011, “ Coal Gasification in CO2 Atmosphere and Its Kinetics Since 1948: A Brief Review,” Energy, 36(1), pp. 12–40. [CrossRef]
Kajitani, S. , Suzuki, N. , Ashizawa, M. , and Hara, S. , 2006, “ CO2 Gasification Rate Analysis of Coal Char in Entrained Flow Coal Gasifier,” Fuel, 85(2), pp. 163–169. [CrossRef]
Kreitzberg, T. , Haustein, H. D. , Gövert, B. , and Kneer, R. , 2016, “ Investigation of Gasification Reaction of Pulverized Char Under N2/CO2 Atmosphere in a Small-Scale Fluidized Bed Reactor,” ASME J. Energy Resour. Technol., 138(4), p. 042207. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Hypothetical subprocesses of the detailed gasification model proposed by Prins and Ptasinski Tr and P are the gasification temperature and pressure, respectively

Grahic Jump Location
Fig. 2

Algorithm flow chart of carbon gasification. The matlab algorithm flow chart of carbon gasification, which is calculated using the kinetic method and obeys mass conservation and the first and second law of thermodynamics. ni represents the mole number of the component i. Rj represents the reaction rate of Reaction j. e, A, dH, and Ex are the interim parameters obtained at every time period.

Grahic Jump Location
Fig. 3

Variation of reaction extents ej with time under the base condition

Grahic Jump Location
Fig. 4

Variation of mole numbers ni with time under the base condition

Grahic Jump Location
Fig. 5

EUD of the gasification process. ΔH is the enthalpy change and A is the energy level of each subprocess. The shadow areas represent the exergy destructions of each subprocess.

Grahic Jump Location
Fig. 6

Key simulation results including reaction temperature, overall exergetic efficiency, and chemical efficiency under the carbon deposition boundary conditions [16]. α and β are the coupled O2/C and H2O/C under the carbon deposition boundaries.

Grahic Jump Location
Fig. 7

Relationship of chemical efficiency and reaction extents. e1, e3, and e8 are the reaction extents of the partial oxidation reaction, steam gasification reaction, and shift reaction, respectively.

Grahic Jump Location
Fig. 8

Distribution of the exergy destruction and physical exergy output under five representative conditions. Each color represents a specific exergy destruction of the corresponding subprocess, and the origin color represents the physical exergy output.

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