Heat Integration Pinch Technology What is pinch technology

Heat Integration: Pinch Technology What is pinch technology? Methodology for minimizing energy consumption by optimizing heat recovery systems Objective of pinch analysis q. To achieve financial saving by constructing the best process heat integration q. To optimize the process heat recovery and reducing external utility loads

Heat Integration: Methodology Identification of hot, cold and utility streams in the process Thermal data extraction for process and utility streams Selection of initial ∆Tmin value Construction of problem table algorithm Identification Tpinch, QH, min and QC, min via heat cascade table Construction of heat exchanger network Calculation of energy saving

Cold Stream Hot Stream BACK

Heat Integration: Methodology Stream BACK No. Name (Refer to i. CON) Name Type Supply temperature TS(°C) Target temperature TT(°C) Utility ∆H (k. W) 1 E 105 H 1 Hot 427. 22 204. 44 32328. 6998 2 E 103 H 2 Hot 220. 00 40. 00 59263. 3538 3 E 115 H 8 Hot 460. 00 300. 00 27361. 2603 4 E 116 H 9 Hot 300. 00 150. 00 25379. 6722 5 E 107 C 1 Cold 50. 00 290. 00 20253. 3355 6 E 113 C 2 Cold 30. 00 189. 61 28841. 6240 7 E 114 C 3 Cold 189. 61 350. 00 28715. 1726

Heat Integration: Methodology Stream Supply Target temperature CP(k. W/°C) TS(°C) TT(°C) No. Name (Refer to i. CON) Name Type 1 E 105 H 1 Hot 427. 22 204. 44 2 E 103 H 2 Hot 220. 00 3 E 115 H 8 Hot 4 E 116 H 9 5 E 107 6 7 Shifted temperature (°C) Utility ∆H (k. W) ∆Tmin/2 TS* TT* 145. 1149 422. 22 199. 44 32328. 6998 5 40. 00 329. 2409 215. 00 35. 00 59263. 3538 5 460. 00 300. 00 171. 0079 455. 00 295. 00 27361. 2603 5 Hot 300. 00 150. 00 169. 1978 295. 00 145. 00 25379. 6722 5 C 1 Cold 50. 00 290. 00 84. 3889 55. 00 295. 00 20253. 3355 5 E 113 C 2 Cold 30. 00 189. 61 180. 6983 35. 00 194. 61 28841. 6240 5 E 114 C 3 Cold 189. 61 350. 00 179. 0357 194. 61 355. 00 28715. 1726 5 NOTE THAT: : 1 BACK Ts*= Ts - ∆T/2 Tt*= TT + ∆T/2 CP = ∆H/∆T, ∆H is obtained from i. CON 2 ∆Tmin = 10˚C

Heat Integration: Methodology Problem Table Algoritm Interval Temperature (˚C) 455. 00 422. 22 355. 00 295. 00 215. 00 199. 44 194. 61 145. 00 55. 00 35. 00 BACK Stream Population 109 102 110 103 106 104 105 ∆Tinterval (°C) ∑CPC -∑CPH (k. W/°C) ∆Hinterval(k. W) Surplus/Deficit 32. 78 67. 22 60. 00 80. 00 15. 56 4. 83 49. 61 90. 00 20. 00 -171. 0079 -316. 1228 -137. 0871 -50. 8882 -380. 1290 -235. 0141 -378. 4663 30. 4932 -148. 5425 -5605. 6382 -21249. 7738 -8225. 2272 -4071. 0528 -5914. 8075 -1135. 1181 -18775. 7150 2744. 3841 -2970. 8502 Surplus Surplus Surplus

Heat Integration: Methodology Heat Cascade Table Interval temperature (˚C) Tpinch (˚C): 455 + 10/2 = 460˚C 455. 00 422. 22 355. 00 295. 00 215. 00 199. 44 194. 61 145. 00 55. 00 35. 00 ∆Hinterval (k. W) -5605. 6382 -21249. 7738 -8225. 2272 -4071. 0528 -5914. 8075 -1135. 1181 -18775. 7150 2744. 3841 -2970. 8502 Heat flow (k. W) Adjusted heat cascade (k. W) 0. 0000 5605. 6382 26855. 4120 35080. 6392 39151. 6920 45066. 4995 46201. 6176 64977. 3326 62232. 9485 65203. 7987 QH, min QC, min

Heat Integration: Methodology Combine Composite Curve BACK Grand Composite Curve

Heat Integration: Methodology Grid Diagram

Heat Integration: Methodology 1 2 Above pinch region: Cpc > Cph Below pinch region: Cph > Cpc Cp rules: No temperature crossover of hot and cold stream through the heat exchanger

Heat Integration: Methodology Grid Diagram With Heat Exchanger Design 1) 28715 k. W/2 = 171. 0079 k. W/˚C x (460˚C - T) BACK 2) T = 376. 04˚C

Heat Integration: Methodology Name (Refer to i. CON) C 102 C 103 C 109 C 110 H 104 H 105 H 106 ∆H (k. W) Remaining Heat For Cooling Requirement (k. W) 32328. 6998 59263. 3538 27361. 2603 25379. 6722 20253. 3355 28841. 6240 28715. 1726 17971. 1135 30421. 7298 13003. 6740 5126. 3367 0. 0000 Total 222143. 1182 66522. 8540 Total Utility Consumption Before HI Total Utility Consumption After HI

Heat Integration: Methodology Energy Saving After HI Total Utility Consumption Base Case Design Before HI (k. W) 222143. 1182 After HI (k. W) 66522. 8540 Energy Saved 155620. 2642 (k. W) % Reduction BACK 70. 05% = (222, 143. 1182 k. W – 65, 522. 8540 k. W) / 155620. 2642 k. W = 70. 05%