Cyclic deactivation: a novel technique to simulate the deactivation of fcc catalyst in commercial units

Abstract

The principles and application possibilities of Akzo's Cyclic Deactivation Unit are described in this paper. In the CD-Unit the ageing of FCC catalyst is simulated by deactivation in a fixed fluidized bed through repeated cycles of reaction, stripping and regeneration. Metals can be deposited on the catalyst with metals-spiked VGO or resid, while deactivation takes place during the stripping and regeneration cycles. The age distribution of equilibrium catalyst can be simulated by fresh catalyst addition during the CD-deactivation. In this paper we will emphasize the following aspects: A proper simulation of the catalyst deactivation cannot be reached with the traditional PV impregnation method and we will show that this method can result in a reversed performance ranking of different catalysts. In general, the CD-method simulates the commercial performance much better than conventional deactivation procedures. The CD procedure provides a very elegant and convenient way to generate basic knowledge about zeolite and matrix deactivation and the effects of temperature, steam partial pressure, partial or complete CO combustion, metals level, etc. Finally it is shown that the CD-Unit can be used for special FCC catalyst testing purposes, such as the “Catalyst Strippability” and “Vanadium Mobility” testing. The CD-unit can be supplied by Xytel under license of Akzo Chemicals.