RESEARCH ARTICLE

Effective diffusivity of oxygen in the ash layer of Huadian oil shale semicoke

  • Yiqun HUANG 1 ,
  • Yiran LI 1 ,
  • Man ZHANG 1 ,
  • Boyu DENG 1 ,
  • Hao KONG 1 ,
  • Junfeng WANG 2 ,
  • Junfu LYU 1 ,
  • Hairui YANG , 1 ,
  • Lingmei WANG , 3
Expand
  • 1. Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, State Key Laboratory of Power Systems, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
  • 2. State Key Laboratory of Efficient and Clean Coal-fired Utility Boilers (Harbin Boiler Co., Ltd.), Harbin 150046, China
  • 3. Department of Automation, Shanxi University, Taiyuan 030006, China

Received date: 18 Oct 2019

Accepted date: 15 Jan 2020

Published date: 15 Jun 2021

Copyright

2020 Higher Education Press

Abstract

Diffusion of oxygen in the ash layer usually dominated the combustion of oil shale semicoke particles due to the high ash content. Thus, effective diffusivity of oxygen in the ash layer was a crucial parameter worthy of careful investigation. In this paper, the effective diffusivity of oxygen in the ash layer of Huadian oil shale semicoke was measured directly using an improved Wicke-Kallenbach diffusion apparatus. The experimental results showed that higher temperature would lead to a higher effective diffusivity and a thicker ash layer had the negative effect. Especially, the effective diffusivity along the direction perpendicular to bedding planes was much lower than that along the direction parallel to bedding planes. In addition, an effective diffusivity model was developed, which could be used to describe the mass transfer of oxygen in the ash layer of oil shale semicoke.

Cite this article

Yiqun HUANG , Yiran LI , Man ZHANG , Boyu DENG , Hao KONG , Junfeng WANG , Junfu LYU , Hairui YANG , Lingmei WANG . Effective diffusivity of oxygen in the ash layer of Huadian oil shale semicoke[J]. Frontiers in Energy, 2021 , 15(2) : 320 -327 . DOI: 10.1007/s11708-020-0674-3

Acknowledgment

This work was financially supported by the National Natural Science Foundation of China (Grant No. U1810126).
1
Strizhakova Y A, Usova T V. Current trends in the pyrolysis of oil shale: a review. Solid Fuel Chemistry, 2008, 42(4): 197–201

DOI

2
Kok M V. Oil shale: pyrolysis, combustion, and environment: a review. Energy Sources, 2002, 24(2): 135–143

DOI

3
Kuang W, Lu M, Yeboah I, Qian G, Duan X, Yang J, Chen D, Zhou X. A comprehensive kinetics study on non-isothermal pyrolysis of kerogen from green river oil shale. Chemical Engineering Journal, 2019, 377: 120275

DOI

4
Tian Y, Li M, Lai D, Chen Z, Gao S, Xu G. Characteristics of oil shale pyrolysis in a two-stage fluidized bed. Chinese Journal of Chemical Engineering, 2018, 26(2): 407–414

DOI

5
Han X, Kulaots I, Jiang X, Suuberg E. Review of oil shale semicoke and its combustion utilization. Fuel, 2014, 126(12): 143–161

DOI

6
Yang Y, Lu X, Wang Q, Mei L, Song D, Hong Y. Experimental study on combustion of low calorific oil shale semicoke in fluidized bed system. Energy & Fuels, 2016, 30(11): 9882–9890

DOI

7
Qin H, Sun B, Wang Q, Zhou M, Liu H, Li S. Analysis on influence factors of the characteristic of pore structure during combustion of oil shale semi-coke. Proceedings of the CSEE, 2008, 28(35): 14–20 (in Chinese)

8
Wang X, Wang J, Qian J, Zhu Y. Diffusion effects in the ash layer of the oil shale char combustion. Acta Petrolei Sinica (Petroleum Processing Section), 1987, 3(4): 4–11

9
Yang Y, Wang Q, Lu X, Li J, Liu Z. Combustion behaviors and pollutant emission characteristics of low calorific oil shale and its semi-coke in a lab-scale fluidized bed combustor. Applied Energy, 2018, 211: 631–638

DOI

10
Mu M, Han X, Chen B, Jiang X. Oxidation characteristics of the semicoke from the retorting of oil shale and wheat straw blends in different atmospheres. Oil Shale, 2019, 36(1): 43–61

DOI

11
Yörük C R, Meriste T, Sener S, Kuusik R, Trikkel A. Thermogravimetric analysis and process simulation of oxy-fuel combustion of blended fuels including oil shale, semicoke, and biomass. International Journal of Energy Research, 2018, 42(6): 2213–2224

DOI

12
Wang P, Wang C, Du Y, Feng Q, Wang Z, Yao W, Liu J, Zhang J, Che D. Experiments and simulation on co-combustion of semi-coke and coal in a full-scale tangentially fired utility boiler. Energy & Fuels, 2019, 33(4): 3012–3027

DOI

13
Wang J, Wang X. A study of the combustion reaction model of oil shale particles. Acta Petrolei Sinica (Petroleum Processing Section), 1987, 3(3): 1–9

14
Huang Y, Zhang M, Lyu J, Yang H. Modeling study of combustion process of oil shale semicoke in a circulating fluidized bed boiler. Carbon Resources Conversion, 2018, 1(3): 273–278

DOI

15
Han X, Jiang X, Yan J, Liu J. Effects of retorting factors on combustion properties of shale char. 2. porestructure. Energy & Fuels, 2011, 25(1): 97–102

DOI

16
Bai J, Wang Q, Jiao G. Study on the pore structure of oil shale during low-temperature pyrolysis. Energy Procedia, 2012, 17(1): 1689–1696

DOI

17
Tiwari P, Deo M, Lin C L, Miller J D. Characterization of oil shale pore structure before and after pyrolysis by using X-ray micro CT. Fuel, 2013, 107(9): 547–554

DOI

18
Sun W, Chen S, Xu M, Wei Y, Fan T, Guo J. The diffusion of molecules inside porous materials with bidisperse pore structures. Chemical Engineering Journal, 2019, 365: 201–219

DOI

19
Le Blévec J M, Barthel E, Briens C. Measurement of volatile diffusivity in polymer particles. Chemical Engineering & Processing Process Intensification, 2000, 39(4): 315–322

DOI

20
Zheng Y, Wang Q, Yang C, Qiu T. Experimental study on mass transport mechanism in poly (styrene-co-divinylbenzene) microspheres with hierarchical pore structure. Chemical Engineering and Processing, 2019, 139: 183–192

DOI

21
Wheeler A. Reaction rates and selectivity in catalyst pores. Advances in Catalysis, 1951, 3(6): 249–327

DOI

22
Mota O D S, Campos J B L. Combustion of coke with high ash content in fluidised beds. Chemical Engineering Science, 1995, 50(3): 433–439

DOI

23
Laurendeau N M. Heterogeneous kinetics of coal char gasification and combustion. Progress in Energy and Combustion Science, 1978, 4(4): 221–270

DOI

24
Sun J K, Hurt R H. Mechanisms of extinction and near-extinction in pulverized solid fuel combustion. Proceedings of the Combustion Institute, 2000, 28(2): 2205–2213

DOI

25
Wakao N, Smith J M. Diffusion in catalyst pellets. Chemical Engineering Science, 1962, 17(11): 825–834

DOI

26
Johnson M F L, Stewart W E. Pore structure and gaseous diffusion in solid catalysts. Journal of Catalysis, 1965, 4(2): 248–252

DOI

27
Fu W B, Zhang B L. Experimental determination of the equivalent mass diffusivity for a porous coal-ash particle. Journal of Combustionence & Technology, 1995, 101(3): 371–377 (in Chinese)

28
Yan J H, Ni M J, Zhang H T, Cen K F. Gas diffsuion through the ash layer of coal particle. Journal of Engineering Thermophysics, 1994, 15(3): 341–344 (in Chinese)

29
Liu J, Yan J, Han X, Jiang X. Study on the anisotropy of mass transfer for oxygen in the ash layer of shale char particles. Energy & Fuels, 2010, 24(6): 3488–3497

DOI

30
Yang Y, Lu X, Wang Q, Song D, Chen Y, Hong Y. Study on the anisotropy of mass transfer for oxygen in the ash layer of extremely low calorific oil shale semi-coke. Applied Thermal Engineering, 2018, 128: 1494–1501

DOI

31
Wicke E, Kallenbach R. The surface diffusion of carbon dioxide in active carbons. Colloid Journal, 1941, 97(2): 135–151 (in German)

DOI

32
Cao L, He R. Gas diffusion in fractal porous media. Combustion Science and Technology, 2010, 182(7): 822–841

DOI

Outlines

/