ABSTRACT
A refinery is a complex network of vessels, equipment, and pipes. The total scheme can be divided into a number of unit processes. Refined products establish the order in which each refining unit will be introduced. Only one or two key product specifications are used to explain the purpose of each unit. Nevertheless, the choices among several types of units and the sizes of these units are complicated economic decisions. The trade-off among product types, quantity, and quality will be mentioned to the extent that they influence the choice of one kind of process unit over another.
