Page 282 - Sustainability in the Process Industry Integration and Optimization

I n d u s t r i a l A p p l i c a t i o n s a n d Ca s e S t u d i e s 259

CP [kW/°C] CP CP
H11 H12
CP = 17.68 28° 65.5° 94.2°
H11 C2 C1 H1
= 17.68 507.5 kW
CP H12 101.9 kW
40.0° 70.0° 111.3°
0.38 C3 1 H2
11.3 kW
60.0° 75.3° 186.0°
1.66 C4 2 H3
25.4 kW
40.0° 129.8° 197.0°
0.84 C5 3 H4
75.8 kW
100.0° 140.3° 296.3°
0.98 C6 4 H5
39.7 kW
CP C11 = 2.92 20.0° 60.0° 65.3° 119.8° 130.3° 158.7° 310.0°
CP = 5.40 C1 H1 1 2 3 4 H2
C12
= 4.23 CP C11 CP CP
CP C13 C1 C1
1 101.7 kW 11.9 kW 2 183.6 kW 56.7 kW 153.5 kW 677.3 kW 3
(a) Initial HEN Feed 1
CP = 9.286 28.0° 54.7° 101.7°
H11 C2 C1
= 2.086 H1
CP H12 55.7 kW 436.7 kW
40.0° 70.0° 111.6°
0.28 C3 1 H2
8.6 kW
60.0° 74.2° 186.3°
1.25 C4 2 H3
17.70 kW
40.0° 122.1° 196.7°
0.87 C5 3 H4
21.4 kW
1.47 100.0° C6 137.3° 4 294.6° H5
54.8 kW
CP = 2.87 20.0° 60.0° 64.2° 112.1° 127.3° 180.5° 310.0°
C11 H1
CP = 4.25 C1 1 2 3 4 H2
C12
CP = 4.49
C13 114.8 kW 11.9 kW 140.4 kW 64.7 kW 231.1 kW 582.8 kW
(b) Initial HEN Feed 2
= 9.85
CP H11 28.0° 48.5° 96.2°
= 2.27 C2 C1
CP H12 46.6 kW 469.9 kW H1
0.27 40.0° C3 70.0° 1 111.2° H2
8.0 kW
1.15 60.0° C4 73.2° 2 186.0° H3
15.1 kW
0.88 40.0° C5 109.4° 3 197.1° H4
61.2 kW
1.41 100.0° C6 127.6° 4 294.8° H5
38.7 kW
= 3.43
CP C11 20.0° 60.0° 63.2° 99.4° 117.6° 172.2° 310.0°
= 4.25
CP C12 C1 H1 1 2 3 4 H2
CP = 4.46
C13 10.9 kW 129.2 kW 77.7 kW 235.1 kW 614.1 kW
137.0 kW
(c) Initial HEN Feed 3
FIGURE 11.4 Initial HEN for the crude-oil preheating process.
matches is needed. This requirement suggests the repiping of coolers
mentioned previously, which would form three loops for internal
heat transfer.
Another important observation concerns the amount of recovery
from streams H2 to H5. Streams H3 and H4 feature close supply
temperatures. For all three operating points, and especially for that
of feed 1, H3 has substantially greater heat capacity flow rate than