(188c) An Automated Supertargeting Approach for Heating Medium System

Heating utility system is commonly used in offshore platform to provide heating requirement for heavy crude oil of high viscosity from the reservoir. Heating the oil reduces its viscosity and hence improves oil/water separation which eventually leads to reduced size and cost of the separator. In conventional design, heating medium is distributed to the heat exchangers in parallel configuration to provide the required heating. This design however contributes to the overdesign of heating utility system. In this paper, novel process integration approaches based on supertargeting technique is developed. The newly developed technique uses algebraic approach instead of graphical approach proposed by Linnhoff and Ahmad (1990) and Ahmad and Linnhoff (1990). Apart from determining the minimum amount of heating utility, the approach caters for capital and operating cost trade-off for the heat exchanger network (HEN) and waste heat recovery unit (WHRU). An industrial case study is used to elucidate how the newly proposed optimisation technique is used to determine the minimum total cost target for the heating medium utility system.