Configuration and economic evaluation of a cogeneration refinery in Saudi Arabia

The gasification of high-sulfur refinery residues into clean syngas provides an important route for the generation of electric power, hydrogen for refinery applications and the production of selected chemicals. The largest and most near-term application is the production of electric power by the integrated gasification combined cycle process. For the Kingdom of Saudi Arabia, the rapid increase in the demand for electric power (10%/yr) and the surplus of heavy residues justify the addition of a cogeneration plant within the refinery which itself has a significant electric power requirement. The residue gasification option will partly contribute to enhancing the existing power capacity in the Kingdom which stands at ∼23,000 Mw and will have to reach 28,000 Mw by the year 2000 and 59,000 Mw in 2050, according to some industrial analysts. This paper provides configuration and economic analysis of a cogeneration plant in a medium-conversion refinery. The plant is designed to generate 800 Mw electric power for internal use and for export as well as 500 ton/hr HP steam. Economic evaluation has been made for this cogeneration plant using 24,000 bpd (3,800 cu m/day) visbreaker tar. The results of the economic analysis show that the investment needed is relatively high at $808 million, however, the payback period is reasonable within 4.7 yr.