100
600
500
400
300
200
100
0
600
Regular Grade Gasoline
ASTM
ASTM
TBP
Premium Grade Gasoline
TBP
500
400
300
Temp
°F
Temp
°F
200
100
0
90
80
70
60
% Volume
50
40
30
20
10
0
Fig. 12 Premium and
regular grade TBP and ASTM
curves
Table 40 Butane addition to meet RVP spec for premium gasoline
Comp
mid Bpt °F VP @
100°F psia
K = VP/7
moles liq
moles vap
C 4
60
8.57
x
8.57x
1
75
22
3.14
0.395
1.241
2
115
11
1.57
0.298
0.469
3
135
6.2
0.89
0.503
0.445
4
155
5.0
0.71
0.630
0.450
5
185
2.5
0.36
0.515
0.184
6
225
7
260
8
285
1.8
0.26
3.946
1.015
9
315
10
375
11
420
Total
6.287 + x
3.804 +
8.57 x
114
D.S.J. Jones and S.A. Treese