A modified discrete random pore model allowing for different initial surface reactivity

Gupta, J. Srinivasalu ; Bhatia, S. K. (2000) A modified discrete random pore model allowing for different initial surface reactivity Carbon, 38 (1). pp. 47-58. ISSN 0008-6223

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Official URL: http://linkinghub.elsevier.com/retrieve/pii/S00086...

Related URL: http://dx.doi.org/10.1016/S0008-6223(99)00095-0


We investigate here a modification of the discrete random pore model [Bhatia SK, Vartak BJ, Carbon 1996;34:1383], by including an additional rate constant which takes into account the different reactivity of the initial pore surface having attached functional groups and hydrogens, relative to the subsequently exposed surface. It is observed that the relative initial reactivity has a significant effect on the conversion and structural evolution, underscoring the importance of initial surface chemistry. The model is tested against experimental data on chemically controlled char oxidation and steam gasification at various temperatures. It is seen that the variations of the reaction rate and surface area with conversion are better represented by the present approach than earlier random pore models. The results clearly indicate the improvement of model predictions in the low conversion region, where the effect of the initially attached functional groups and hydrogens is more significant, particularly for char oxidation. It is also seen that, for the data examined, the initial surface chemistry is less important for steam gasification as compared to the oxidation reaction. Further development of the approach must also incorporate the dynamics of surface complexation, which is not considered here.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
ID Code:3048
Deposited On:09 Oct 2010 10:14
Last Modified:17 May 2011 07:10

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