The authors have examined the effects of metal components of the catalysts on activity in the liquid phase oxidation of acrolein (Acr.). An oxidation reaction was carried out by flowing oxygen at the atmospheric pressure and a temperature of 2045°C. The V
2O
5 catalyst gave the most desirable results with respect to the selective oxidation. With 10
-2 mol/l of V
2O
5, the conversion of acrolein and the selectivity of acrylic acid (Acr. A.) were 3O40% and about 60%, respectively. The following empirical rate equations were obtained.
-
d [Acr.] /
dt =
k 1 [Acr.]
1.0 [V
2O
5]
0.10d [Acr.A.] /
dt =
k 2 [Acr.]
1.8[V
2O
5]
0.17Values of apparent activation energy for acrolein consumption and acrylic acid formation were 6.8 and 6.5 kcal/mol, respectively. From these equations, the selectivity of acrylic acid could be calculated as follows :
S
Acr.A. =0.154
exp (340/RT) [Acr.]
0.8[V
2O
5]
0.07Thus, the concentration of acrolein appears to have more effect on the selectivity than V
2O
5 concentration and reaction temperature. According to a comparison of various solvents, benzene is considered to give the most desirable activity to the V
2O
5 catalyst for synthesizing acrylic acid.
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