ABSTRACT
The fluid catalytic cracker unit (FCCU) is a very important unit in a refinery. This unit converts low value heavy oil to transportation fuels of a substantial higher value. In order to optimize the catalytic process, it is important to select the catalysts with great care. To maximize the profit, the selected catalyst should fit both the feedstock to the FCC unit as well as the refinery yield demands. However, the feedstocks and the yield demands change continuously and it is therefore necessary to pay particular attention to these issues. For a residue catalytic cracker, like the Statoil unit at the Mongstad refinery in Norway, it is even more important. This FCC unit came on stream in 1989 with a design capacity of 250 t/h [1]. Some years later the rated capacity was increased to 325 t/h [2]. The feed to the catalytic cracker at the Mongstad refinery is mainly a North Sea atmospheric residue [3] and the objective has been to select the most optimal catalyst for this unit; most of the time for maximum naphtha production. For this reason Statoil has had an on-going test and research activity together with Chalmers University in Sweden for many years, using the circulating ARCO pilot unit at the university.
