Maxwell (1968) in his book Data Book on Hydrocarbons. The correlation curves
from both these sources are given as Figs. 6 and 7. In this exercise Edmister’s
method and correlation will be used.
The ASTM distillation is tabulated as the temperature for IBP, 10 %, 20 %,
through to the FBP. IBP is the initial boiling point (equivalent to 0 % over) and the
FBP is the final boiling point (equivalent to 100 % vol over). The multiples of 10 %
reflect the volume distilled and the temperature at which each increment is distilled.
Using Fig. 6, the 50 % vol TBP point (in degrees Fahrenheit) is calculated from the
50 % vol point of the ASTM distillation.
Figure 6 is then used to determine the TBP temperature difference from the ASTM
temperature difference for the 0–10 % vol, 10–30 % vol, 30–50 % vol, 50–70 % vol,
70–90 % vol, and 90–100 % vol. Moving from the established 50 % vol TBP figure
ASTM Temperature Difference °F
ASTM 50% Temperature °F
TBP Temperature Difference
°F
Δ°F(Add to ASTM 50% to Obtain TBP 50%
Temperature)
0
210
200
190
180
170
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
70
60
50
40
30
20
10
–10
–20
0
100
200
300
400
500
600
700
800
900
10 20 30 40
ASTM Temp Diff
vs
TBP Temp Diff
Reference:
Edolater-Okanato, Pet, Ref. 38
Number 3, pp 117-129 (1965)
ASTM 50% Temp
vs
TBP 50% Temp
S e g m
e n t o f D
is
t il la
t io
n
C
u r v e , V o lu
m
e
P e r c e n t
9 0 %
t o
1 0 0 %
9 0 %
t o
1 0 0 %
9 0 %
t o
1 0 0 %
7 0 %
t o
9 0 %
7 0 %
t o
9 0 %
7 0 %
t o
9 0 %
5 0 %
t o
7 0 %
5 0 %
t o
7 0 %
5 0 %
t o
7 0 %
3 0 %
t o
5 0 %
3 0 %
t o
5 0 %
3 0 %
t o
5 0 %
1 0 %
t o
3 0 %
1 0 %
t o
3 0 %
1 0 %
t o
3 0 %
0 %
t o
1 0 %
0 %
t o
1 0 %
0 %
t o
1 0 %
50 60 70 80 90 100 110 120 130 140 150 160 170 180
Reference:
Edolater & Pollack, CEP,
qs. pp 907 (1948)
Fig. 6 ASTM–TBP correlation – Edmister method
20
D.S.J. Jones