Optimum Heat Exchanger Network Cleaning Schedules for Crude Distillation Unit

• Main Author: Zulkafli, Nur Izyan
• Format: Conference or Workshop Item
• Language: English
• Published: 2012
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://eprints.utem.edu.my/id/eprint/10524/2/Optimum_Heat_Exchanger_Network_Online_Cleaning_Schedules.pdf; http://eprints.utem.edu.my/id/eprint/10524/

There is greater awareness today on the depleting fossil energy resources and the growing problem of atmospheric pollution. Engineers are developing practical techniques to ensure energy processes are designed and operated efficiently. Inefficient furnaces and heat exchangers contribute to the problem due to higher fuel demand and higher carbon emission. In crude preheat train (CPT), fouling causes the reduction of heat transfer efficiency, which leads to higher furnace fuel consumption, and exert additional cost for heat exchanger cleaning and lost production. This article presents optimum scheduling for retrofit and/or cleaning of heat exchangers in the CPT. There are three cases in this study. The cases are plant shutdown for overall cleaning of CPT (Case 1), online cleaning of heat exchangers (Case 2) and combined online cleaning with retrofit of high efficiency heat exchangers (Case 3). The largest energy and carbon dioxide emission savings are found from Case 3. The installation of high efficiency heat exchangers improves furnace inlet temperature (FIT) from 215oC to 227oC. Furthermore, Case 3 results in the highest percentage of cost saving by about 71% and 62% with and without carbon credit, respectively. The payback period for investment in high efficiency heat exchangers is 3 months, with carbon credit, and 4 months, without carbon credit, respectively. Thus, Case 3 is the most cost effective option for reductions of energy consumption and carbon dioxide emission in the CDU.