Many different types of crude oils are extracted from Mexican wells and mixed to produce commercial mixtures that are well known and highly demanded in the export market. These mixtures are also used as feed in Mexican refineries. However, to make the best out of our refineries, crude oils should be mixed according to the particular characteristics of each refinery. It is also possible to define optimal operating conditions for a particular refinery as a function of the crude mixture. Processing of heavy crude in existing refineries can not be significantly increased because of limitations such as: a decrease in the yield of light products, equipment metal restrictions, and greater environmental impact. However, it is our belief, that the efficiency of the oil industry can be significantly increased. This paper visualizes one approach: improving the productivity of individual refineries in order to increase heavy crude refining capacity and reduce costs. We develop an optimization model of a typical FCC-configuration refinery and analyze alternative ways of improving heavy crude processing efficiency. Our modeling efforts concentrate on the selection of the ideal mixture of crude and on hydrotreating and catalytic cracking of atmospheric and vacuum gas oils.
The demand for gasoline is affected by many factors including quality of available crude oils and environmental regulations influencing finished products. The demand for lighter products and middle distillates has grown steadily as a result of transportation demand and the lack of economically viable alternatives. Optimum conversion capacity provides refiners with flexibility to process heavy crudes and acts as a hedge against high-cost light crudes. This flexibility is required to be more competitive in the marketplace. However, the refiner must select the appropriate process configuration that best fits the combination of crude supply and market demands. The principal rationale for upgrading gasoline, particularly for production of low sulfur gasoline, is to observe new stringent regulations on gasoline fuel quality1–3.
Changes in regulations governing gasoline composition continue to focus on reducing sulfur levels.
Examples include those counties like USA and Canada, that mandating 30 ppm S, will become effective between 2004–2006, and 50 ppm S will be required in the EU in 20054, 6. The overall impact of such regulations on the makeup of the USA and Mexico gasoline pool can be illustrated in Figure 1, which combines historic and forecast specification to levels of sulfur in gasoline. In 2001, with new regulations in several northern European countries, and overall growth in demand, low sulfur gasoline will likely make up about 3.3 thousands of barrels per day (MBD),