An MILP model for heat exchanger network design of a crude refinery with multiple types of crude

Abstract

Because of the increase of oil prices, capital investment in industry in general has become dramatically higher. It is apparent that energy usage reduction is one factor in decreasing such operating costs in the industrial sector. One of the most effective ways to reduce energy usage in a refinery is to design efficient heat exchanger networks (HENs). This study improved the energy consumption of refinery unit. The procedure was divided into two parts. First, the retrofit potential of refinery was studied in order to find scope of energy saving by pinch analysis and grassroots model of GAMS was applied to design the heat exchanger network for a crude refinery. To check the retrofit potential of the crude refinery, a composite curve was used to confirm the utility consumption. The result showed that the existing network consumed 67,536 kW and 9,818 kW of hot and cold utility, respectively, and pinch point was located at 305°C to 271.5°C where ΔTmin is 33.5°C. The result from the grassroots design gave 59,944.74 kW of hot utility usage and 2,152.41 kW of cold utility usage with 43 new heat exchangers. Second, the grassroots design of HENs with multiple types of crude-Arabian light, Rebco and Syrian crude-was done and validated by PRO II software to find the optimal network of refinery.