Application of simulation program for debottlenecking of oil refinery capacity : a case study of the Banchak Refinery

Abstract

This thesis represents the application of a simulator to eliminate the limits of capacity expansion or to debottleneck capacity. The simulator is used to model the exiting process (or to generate a process model) and to simulate this model for bottleneck identification, and then for debottlenecking. The case study is the Topping Unit in plant No.2 of Bangchak Refinery which is expanded from 40 KiloBarrels per Day (or KBD) to 50 and 60 KBD. From simulated results, debottleneckings are as follows: Columns bottlenecks are debottlenecked by two methods. Internal tray modification is only applied to light bottlenecks (usually, less than 94% flooding). For more serious bottlenecks, packing replacement is used. Heat exchange network (or HEN) is redesigned to the new HEN by pinch analysis. Area increases from new heat exchanger equate 20% increase for 50 KBD and 50% area increase for 60 KBD. Coolers and heaters are usually debottlenecked by adding new units in parallel connection. In addition, preliminary economic evaluation of the debottlenecking shows that this debottlenecking should be invested because it yields high rate of return (about 50%IRR) and short payback period (about 2 years). When comparing two capacities, the 50 KBD is more attractive for debottlenecking than the 60 KBD because it has les bottlenecks and thus leading to less complex modifications.