As a result of the development of industrial organic synthesis, the output of secondary processes in oil processing is becoming increasingly diverse. Production volume is a nodal indicator that is limited by the available production capacity, equipment configuration and the monetary equivalent of energy costs. In order to determine the technological potential and cost of produced petroleum products, it is necessary to create a complex that includes all stages of production. The most important criterion for evaluating the energy efficiency of an oil refinery is the relative energy consumption, which depends on its complexity. This criterion can be presented as a set of the different types of energy resources used in the course of production and applied to the total production. For this purpose, the energy resources invested in the given technology should be referred to a finished product or raw material. The peculiarity of oil refineries is that, due to the variety of oil derivatives, energy consumption, as a set of different installations, is much more appropriate to relate not to individual target products but to the amount of processed oil. In practice, all types of energy carriers must be converted to an equivalent value. This paper provides an in-depth analysis of the energy costs of oil refineries. The collection of energy flows of different types and dimensions is the subject of the present study. Based on this, a method is presented that allows a comparison of the energy efficiency of refineries with different capacity and configuration of crude oil processing stages based on the energy index and the equivalent distillation performance.

This paper presents the results of thermodynamic analysis of the crude distillation units of two refineries in Nigeria. The analysis was intended to assess the thermodynamic efficiencies of the refineries and proffer methods of improving the efficiencies. Presented results show the atmospheric distillation units of the refineries have 33.3% and 31.6% exergetic efficiencies and 86.5% and 74.6% energetic efficiencies, respectively. Modifications of the operating and feed conditions of the refineries resulted in increased exergetic efficiencies for as much as 62.3% and 38.7% for the refineries. Thermodynamic analysis of the refineries can bring about efficiency improvement and effectiveness of the refineries.