Hydrocarbon EnginEEring Planning ahead Xiquan Zhang

Technology, describe how taking an integrated approach to energy performance early in the design phase can deliver significant improvements in refinery energy efficiency. E nergy is the second single largest component of variable refinery operating expense, representing some 40-50% of total operating costs, excluding the cost of purchasing raw crude. Fuel and power consumption is also directly related to CO 2 emissions production, and there are also strong economic and environmental pressures to reduce greenhouse gas (GHG) emissions. The energy efficiency of a refinery is typically measured by the Solomon Energy Intensity Index (EII), which normally ranges from 60 up to 140, where a lower number represents greater energy efficiency. The EII value is a validated and standardised measure of energy usage that accounts for scale, location, and complexity of the production facility and operational performance. For a typical 100 000 bpd refinery, an EII reduction of one point is worth approximately US$ 1.7 million/yr at US$ 5/MMBTU fuel price. The operational energy performance of a complex site depends on the individual process unit technologies, efficiencies of individual equipment items, and the effectiveness of the utility system design and the level of heat integration inside and outside of the process unit boundaries. It is possible to have highly efficient individual process unit designs but poor overall site energy performance, due to missed opportunities for inter unit integration, inappropriate steam header pressures,