富氧燃烧(oxyfuel combustion)采用纯氧作为助燃剂以富集烟气中CO2,同时采用循环烟气(高浓度CO2)或者水蒸气(H2O)作为中和剂,降低纯氧燃烧的高温。被视为最易于工业化和商业化实现二氧化碳捕集、利用与封存(CCUS)的新型燃烧方式。高压富氧燃烧能够实现高效率的能量转换,因而被认为是一种新型的高效低污染燃烧方式。本课题组已经发展了适用C0-C2富氧气氛和空气气氛的详细反应动力学模型OXYMECH。
表1 甲烷富氧燃烧机理中更新的反应
Reaction |
A |
n |
EA |
|
CH4 + OH ó CH3 +H2O |
2.30E+08 |
1.40 |
2850.0 |
|
CH4 + Hó CH3 + H2 |
4.78E+05 |
2.50 |
9588.0 |
|
CH3 + CH3 (+M) ó C2H6 (+M) |
2.50E+13 |
0.00 |
0.00 |
|
Low-pressure limit |
2.33E+34 |
-5.03 |
-1200.0 |
|
a = 0.38, T3 = 73.0, T1 = 1180.0 |
表2 乙烷富氧燃烧机理中更新的反应
Reaction |
A |
n |
EA |
|
C2H6 + HO2 ó C2H5 + H2O2 |
1.10E+05 |
2.5 |
16850 |
|
C2H6 + OH ó C2H5 + H2O |
9.46E+06 |
2.0 |
994 |
|
C2H6 + H ó C2H5 + H2 |
1.13E+08 |
1.9 |
7530 |
|
C2H6 + CH3 ó C2H5 + CH4 |
5.60E+10 |
0.0 |
9420 |
|
Duplicate |
||||
C2H6 + CH3 ó C2H5 + CH4 |
8.30E+14 |
0.0 |
22260 |
|
Duplicate |
||||
C2H6 + O ó OH + C2H5 |
1.76E+05 |
2.8 |
5803 |
|
C2H5 + O2 ó HO2 + C2H4 |
1.36E+07 |
1.1 |
-1975 |
|
C2H4 + H (+M) ó C2H5 (+M) |
1.23E+09 |
1.5 |
1355 |
|
Low-pressure limit |
2.03E+39 |
-6.6 |
5769 |
|
a = 1.6, T3 = -9147, T1 = 299, ,T2 = 152 |
||||
C2H4 + OH ó C2H3+H2O |
2.14E+04 |
2.7 |
2216 |
|
C2H4 + H ó C2H3 + H2 |
2.20E+02 |
3.6 |
11270 |
|
2CH3 ó H + C2H5 |
7.62E+12 |
0.1 |
1060 |
|
CH3 + HO2 ó OH + CH3O |
8.82E+12 |
0.0 |
-590 |
|
CH3 + HO2 ó O2 + CH4 |
1.27E+05 |
2.2 |
-3022 |
|
CH3 + O ó H + CH2O |
5.72E+13 |
0.0 |
0 |
|
HCO + H ó H2 + CO |
8.48E+13 |
0.0 |
0 |
|
CO + OH ó H + CO2 |
6.19E+04 |
2.1 |
-356 |
|
Duplicate |
||||
CO + OH ó H + CO2 |
5.0E+12 |
-0.7 |
332 |
|
Duplicate |
||||
H2O2 (+M) ó 2OH (+M) |
2.19E+12 |
0.9 |
48750 |
|
Low-pressure limit |
2.49E+24 |
-2.3 |
48750 |
|
a = 0.58, T3 = 30, T1 = 90000, ,T2 = 90000 |
||||
H+O2 ó O + OH |
9.84E+13 |
0.0 |
15310 |
|
2HO2 ó H2O2 + O2 |
1.96E+11 |
0.0 |
-1409 |
|
Duplicate |
||||
2HO2 ó H2O2 + O2 |
1.11E+14 |
0.0 |
11040 |
|
Duplicate |
||||
HO2 + H ó H2 + O2 |
2.95E+06 |
2.1 |
-1455 |
|
HO2 + H ó 2OH |
5.89E+13 |
0.0 |
300 |
|
HO2 + H ó O + H2O |
1.63E+12 |
0.0 |
0 |
|
OH + H2 ó H + H2O |
2.26E+08 |
1.5 |
3437 |
|
H + O2 (+M) ó HO2 (+M) |
4.57E+12 |
0.4 |
0 |
|
Low-pressure limit |
6.37E+20 |
-1.7 |
525 |
|
a = 0.5, T3 = 30, T1 = 90000, ,T2 = 90000 |
在Aramco 1.3的基础上对其中一些基元反应的反应速率常数进行了更新修正,如表1所示,使修改后的模型能够更好的与现有的富氧气氛下甲烷的着火延迟时间相匹配,将修改更新后的模型称为OXYMECH-1。
基于OXYMECH-1进行更新与优化得到预测乙烷着火延迟时间的模型OXYMECH-2,其主要更新、优化的化学反应和相应的化学反应速率常数见表2。