Page 284 - 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 261

28.0° 101.85 kW 65.5° 94.2°
C2 C1 H1
52.1° 507.47 kW
40.0° 111.3°
C3 1 H2
4.54 kW
60.0° 130.2° 186.0°
EC4 2 H3
40.0° 115.3° 197.0°
EC5 3 H4
100.0° 147.3° 296.3°
EC6 4 H5
27.7° 49.4° 89.4° 105.3° 120.0° 137.0° 165.0°
20.0° 310.0°
C1 1 EC5 EC4 EC6 3 2 4 H2
22.3 kW 63.5 kW 116.6 kW 46.6 kW 68.9 kW 92.5 kW 146.6 kW 609.9 kW
(a) Modified HEN Feed 1
28.0° 55.7 kW 54.7° 111.7°
C2 C1 H1
53.2° 436.7 kW
40.0° 111.6°
C3 1 H2
3.79 kW
60.0° 134.5° 186.3°
EC4 2 H3
40.0° 117.0° 196.7°
EC5 3 H4
100.0° 149.8° 294.6°
EC6 4 H5
20.0° 25.8° 49.1° 81.6° 107.0° 124.0° 138.0° 187.0° 310.0°
C1 1 EC5 EC4 EC6 3 2 4 H2
16.7 kW 66.7 kW 93.3 kW 73.2 kW 69.0 kW 64.8 kW 212.7 kW 549.2 kW
(b) Modified HEN Feed 2

28.0° 55.70 kW 48.5° 96.2°
C2 C1 H1
40.0° 39.8° 436.72 kW 111.2°
C3 1 H2
0 kW
60.0° 99.4° 186.0°
EC4 2 H3
40.0° 65.1° 197.1°
EC5 3 H4
100.0° 122.7° 294.8°
EC6 4 H5
20.0° 25.5° 31.9° 45.2° 54.5° 89.4° 112.7° 169.1° 310.0°
C1 1 EC5 EC4 EC6 3 2 4 H2
18.9 kW 22.1 kW 45.1 kW 32.0 kW 116.5 kW 99.1 kW 241.9 kW 608.1 kW
(c) Modified HEN Feed 3
FIGURE 11.5 Modifi ed HEN for the crude-oil preheating process.

exchangers can be used to satisfy the increased area needs for
matches 3, EC5, and EC6. Thus the investment, which is estimated
to be $42,330, is only for the additional area of EC4. Overall, the
modified heat recovery system yields a significant reduction in
energy cost. The total sum of savings after the retrofit is estimated