Combustion of Pulverised Coal in a Mixture of Oxygen and Recycled Flue Gas

A

Appendix

A.1 Global char reaction rates

A.1.1 Char-${\mathbf{CO}}_{\mathbf{2}}$ reaction rates

Half Order Model according to Mann and Kent [195]

Reaction rate:

$\begin{array}{cc}\hfill \frac{{\mathit{dm}}_C}{\mathit{dt}}=& -\pi ·d_P^2·k_{\mathit{kin}\text{,}{\mathrm{CO}}_2}·\frac{\sqrt{k_{\mathit{kin}\text{,}{\mathrm{CO}}_2}^2+4·p_{{\mathrm{CO}}_2}·k_{\mathit{diff}\text{,}{\mathrm{CO}}_2}^2}-k_{\mathit{kin}\text{,}{\mathrm{CO}}_2}}{2·k_{\mathit{diff}\text{,}{\mathrm{CO}}_2}}\hfill \\ \hfill k_{\mathit{kin}\text{,}{\mathrm{CO}}_2}=& k_{0\text{,}\mathit{kin}\text{,}{\mathrm{CO}}_2}·\exp \left(-\frac{E_A}{R·T_P}\right)\hfill \\ \hfill k_{\mathit{diff}\text{,}{\mathrm{CO}}_2}=& \frac{k_{0\text{,}\mathit{diff}\text{,}{\mathrm{CO}}_2}}{d_P}·{\left(\frac{T_G+T_P}{2}\right)}^{0\text{,}75}\hfill \end{array}$

Parameters:

$\begin{array}{cc}\hfill k_{0\text{,}\mathit{kin}\text{,}{\mathrm{CO}}_2}=& 7\text{,}32·{10}^{-2}\left[\frac{\mathit{kg}}{m^2·s·{\mathit{Pa}}^n}\right]\hfill \\ \hfill k_{0\text{,}\mathit{diff}\text{,}{\mathrm{CO}}_2}=& 1·{10}^{10}\left[\frac{\mathit{kg}·m}{m^2·s·\mathit{Pa}·K}\right]\hfill \\ \hfill E_A=& 115·{10}^6\left[\frac{J}{\mathit{kmol}}\right]\hfill \end{array}$

First Order Model according to Mayers [196]

Graphite

Reaction rate:

$\begin{array}{cc}\hfill \frac{{\mathit{dm}}_C}{\mathit{dt}}=& -\pi ·d_P^2·k·p_{{\mathrm{CO}}_2}^n\hfill \end{array}$