Cogeneration refinery for total residue destruction

A very attractive option to refiners is to build a cogeneration plant in areas where electrical power is scarce or where combustible residue is in excess. Availability of such residue is increasing because crude runs are getting heavier and more bottom-of-the-barrel products are being made. Power-generation burnables'' include asphaltic materials such as vacuum and atmospheric residues. The authors investigated the technology and economics of alternative deep conversion schemes, aiming for zero residual fuel oil production. The first scheme is based on high-conversion residue hydrocracking with maximum production of transportation fuels, gasoline and diesel. These meet current and possibly more severe future specifications. The second scheme produces high-quality transportation fuels. But it achieves the zero-residue target by cogeneration of steam and power with the power with the bottom-of-the-barrel residue. This scheme is attracting interest in several European countries affected by a surplus of heavy residue and a shortage of power. Profitabilities of cogeneration and conversion are essentially equivalent for the product prices assumed in their base case but can become quite different when prices of products and electric energy are changed. Investment costs for a cogeneration plant are higher than for a conversion plant. But the cogeneration plant has a shortermore » payout time. Consequently, it should be more profitable in the long run.« less