MODELING CHAR OXIDATION AS A FUNCTION OF PRESSURE ...
MODELING CHAR OXIDATION AS A FUNCTION OF PRESSURE ... MODELING CHAR OXIDATION AS A FUNCTION OF PRESSURE ...
4.0x10 -3 Rate (gC/cm 2 /sec) 3.0 2.0 1.0 0.0 char #2 char #4 1" to 2" 2" to 4" 4" to 6" 1" to 6" overall Figure A.12. High temperature reactivities (based on external surface area) of Koonfontain chars from reactor conditions #2 and #4. χ factor 0.30 0.20 0.10 0.00 char #2 char #4 1~2" 2~4" 4~6" Figure A.13. Values of factor in three intervals of reaction length for Koonfontain char oxidation at reactor condition #2 (CH 4 fuel-lean) and condition #4 (CO fuel-lean). 166
Rate (gC /g C remaining /sec) 1.6x10 -3 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 20 40 60 %Burnout 167 80 100 #2@2" #2@4" #2@6" #2@1" #4 @ 1" #4 @ 2" #4 @ 4" #4 @ 6" Figure A.14. TGA reactivities of Koonfontain chars from reactor conditions #2 and #4 collected at 1”, 2”, 4”, and 6”. Elemental Analysis 120 From Tables A.7 and A.8, it can be seen that the chars made in fuel-lean conditions have lower H/C mole ratio than those chars made in fuel-rich conditions, as shown in Figure A.15. This may explain the higher reactivities of the chars made in fuel- rich conditions, since char reactivity has been correlated with hydrogen content (Charpenay et al., 1992).
- Page 135 and 136: q = A 1p e − E 1 p / RT P os 1 +
- Page 137 and 138: m obs = 0 at high temperatures) and
- Page 139 and 140: Currently the correlations between
- Page 141 and 142: 8. Summary and Conclusions The obje
- Page 143 and 144: 0.5 due to the contribution from th
- Page 145 and 146: Langmuir rate equation, the reactio
- Page 147 and 148: II, in agreement with many observat
- Page 149 and 150: 9. Recommendations The predictive c
- Page 151 and 152: References Ahmed, S., M. H. Back an
- Page 153 and 154: Essenhigh, R. H., D. Fortsch and H.
- Page 155 and 156: Mehta, B. N. and R. Aris , “Commu
- Page 157 and 158: Szekely, J. and M. Propster, "A Str
- Page 159 and 160: Appendices 139
- Page 161 and 162: Introduction Appendix A: Experiment
- Page 163 and 164: detaching the flame from the burner
- Page 165 and 166: To study the effects of steam, CO w
- Page 167 and 168: times at heights of 1, 2, 4, and 6
- Page 169 and 170: analysis. The char reactivities (in
- Page 171 and 172: Table A.5. Moisture, Ash and ICP Ma
- Page 173 and 174: Table A.9. Elemental Analyses of Fo
- Page 175 and 176: temperature profile of the post-fla
- Page 177 and 178: Apparent densities 1.00 0.75 0.50 0
- Page 179 and 180: This observation is somewhat surpri
- Page 181 and 182: It is interesting to compare Figure
- Page 183 and 184: The N 2 BET surfacea areas and H/C
- Page 185: collected in the #4 reactor conditi
- Page 189 and 190: close to zero, the accumulated erro
- Page 191: Appendix B: Errors and Standard Dev
4.0x10 -3<br />
Rate (gC/cm 2 /sec)<br />
3.0<br />
2.0<br />
1.0<br />
0.0<br />
char #2<br />
char #4<br />
1" to 2" 2" to 4" 4" to 6" 1" to 6" overall<br />
Figure A.12. High temperature reactivities (based on external surface area) of<br />
Koonfontain chars from reactor conditions #2 and #4.<br />
χ factor<br />
0.30<br />
0.20<br />
0.10<br />
0.00<br />
char #2<br />
char #4<br />
1~2" 2~4" 4~6"<br />
Figure A.13. Values of factor in three intervals of reaction length for Koonfontain char<br />
oxidation at reactor condition #2 (CH 4 fuel-lean) and condition #4 (CO<br />
fuel-lean).<br />
166
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