### Abstract

In this study, the analytical solution of the mass transfer rate of oxidant to coal char particle surface with partial oxidation in an O_{2}/N_{2} system was extended to that in an O_{2}/CO_{2} system. The difference in the mass transfer mechanism of oxidant in the two systems was investigated by comparing the mass transfer rate of oxidant to char particle surface in these systems. As a result, the mass transfer rate of oxidant to char particle surface was found to be smaller in the O_{2}/CO_{2} system than the O_{2}/N_{2} system, corresponding to the diffusion coefficients when mass transfer is considered to occur by diffusion alone. The effect of convection due to the product of partial oxidation in the O_{2}/CO_{2} system was found to be smaller in O_{2}/N_{2} with an increase in volume fraction of oxidant. Therefore, the mass transfer rate of oxidant in O_{2}/CO_{2} is greater than the difference in diffusion coefficient when both diffusion and convection due to the product of partial oxidation are taken into account. The model parameter in the analytical solution for mass transfer rate of oxidant with diffusion and convection due to the product of oxidation cannot be treated as constant in the O_{2}/CO_{2} system and needs to be calculated according to volume fraction of oxidant, whereas it can be treated as constant in the O_{2}/N_{2} system. The transition temperature from chemical reaction rate-controlling to mass transfer rate-controlling of oxidant is lower in the O_{2}/CO_{2} system than the O_{2}/N_{2} system.

Original language | English |
---|---|

Pages (from-to) | 384-390 |

Number of pages | 7 |

Journal | kagaku kogaku ronbunshu |

Volume | 38 |

Issue number | 6 |

DOIs | |

Publication status | Published - Nov 30 2012 |

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### All Science Journal Classification (ASJC) codes

- Chemistry(all)
- Chemical Engineering(all)

### Cite this

_{2}/CO

_{2}system.

*kagaku kogaku ronbunshu*,

*38*(6), 384-390. https://doi.org/10.1252/kakoronbunshu.38.384

**Estimation of mass transfer rate of oxidant to coal char particle surface with partial oxidation reaction in O _{2}/CO_{2} system.** / Kim, Hyun Seok; Matsushita, Yohsuke; Nozawa, Sohey; Miyawaki, Jin; Yoon, Seong-Ho; Mochida, Isao.

Research output: Contribution to journal › Article

_{2}/CO

_{2}system',

*kagaku kogaku ronbunshu*, vol. 38, no. 6, pp. 384-390. https://doi.org/10.1252/kakoronbunshu.38.384

_{2}/CO

_{2}system. kagaku kogaku ronbunshu. 2012 Nov 30;38(6):384-390. https://doi.org/10.1252/kakoronbunshu.38.384

}

TY - JOUR

T1 - Estimation of mass transfer rate of oxidant to coal char particle surface with partial oxidation reaction in O2/CO2 system

AU - Kim, Hyun Seok

AU - Matsushita, Yohsuke

AU - Nozawa, Sohey

AU - Miyawaki, Jin

AU - Yoon, Seong-Ho

AU - Mochida, Isao

PY - 2012/11/30

Y1 - 2012/11/30

N2 - In this study, the analytical solution of the mass transfer rate of oxidant to coal char particle surface with partial oxidation in an O2/N2 system was extended to that in an O2/CO2 system. The difference in the mass transfer mechanism of oxidant in the two systems was investigated by comparing the mass transfer rate of oxidant to char particle surface in these systems. As a result, the mass transfer rate of oxidant to char particle surface was found to be smaller in the O2/CO2 system than the O2/N2 system, corresponding to the diffusion coefficients when mass transfer is considered to occur by diffusion alone. The effect of convection due to the product of partial oxidation in the O2/CO2 system was found to be smaller in O2/N2 with an increase in volume fraction of oxidant. Therefore, the mass transfer rate of oxidant in O2/CO2 is greater than the difference in diffusion coefficient when both diffusion and convection due to the product of partial oxidation are taken into account. The model parameter in the analytical solution for mass transfer rate of oxidant with diffusion and convection due to the product of oxidation cannot be treated as constant in the O2/CO2 system and needs to be calculated according to volume fraction of oxidant, whereas it can be treated as constant in the O2/N2 system. The transition temperature from chemical reaction rate-controlling to mass transfer rate-controlling of oxidant is lower in the O2/CO2 system than the O2/N2 system.

AB - In this study, the analytical solution of the mass transfer rate of oxidant to coal char particle surface with partial oxidation in an O2/N2 system was extended to that in an O2/CO2 system. The difference in the mass transfer mechanism of oxidant in the two systems was investigated by comparing the mass transfer rate of oxidant to char particle surface in these systems. As a result, the mass transfer rate of oxidant to char particle surface was found to be smaller in the O2/CO2 system than the O2/N2 system, corresponding to the diffusion coefficients when mass transfer is considered to occur by diffusion alone. The effect of convection due to the product of partial oxidation in the O2/CO2 system was found to be smaller in O2/N2 with an increase in volume fraction of oxidant. Therefore, the mass transfer rate of oxidant in O2/CO2 is greater than the difference in diffusion coefficient when both diffusion and convection due to the product of partial oxidation are taken into account. The model parameter in the analytical solution for mass transfer rate of oxidant with diffusion and convection due to the product of oxidation cannot be treated as constant in the O2/CO2 system and needs to be calculated according to volume fraction of oxidant, whereas it can be treated as constant in the O2/N2 system. The transition temperature from chemical reaction rate-controlling to mass transfer rate-controlling of oxidant is lower in the O2/CO2 system than the O2/N2 system.

UR - http://www.scopus.com/inward/record.url?scp=84870002715&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84870002715&partnerID=8YFLogxK

U2 - 10.1252/kakoronbunshu.38.384

DO - 10.1252/kakoronbunshu.38.384

M3 - Article

AN - SCOPUS:84870002715

VL - 38

SP - 384

EP - 390

JO - Kagaku Kogaku Ronbunshu

JF - Kagaku Kogaku Ronbunshu

SN - 0386-216X

IS - 6

ER -