Matrix composition effects coke yield

A number of FCC catalysts was used in the present study. For comparison of the effects of quinoline and phenanthrene additions to the n-hexadecane feedstock a model catalyst of composition, zeolite US-Y (30%), silica binder (25%), Kaolin (25%) and ps do Boehmite matrix (20%) was used. Quinoline and phenanthrene additions to the n-hexadecane amounted to 1% and 10%. The catalysts used to assess the effect of composition on product yields varied from a basic matrix material through a variety of zeolitic catalysts containing 20% zeolite and 15% silica binder, the remainder being clay, to a pure zeolite catalyst. Data for all the catalysts used are presented in Table 1. In addition for the C NMR analysis a sample of coked refinery catalyst obtained from a unit processing heavy feedstock was obtained. The coke level on this catalyst was 0.9% and 30g. of this catalyst was demineralised by standard HF treatment to produce a 250 mg sample of coke concentrate containing 65% carbon. 

In this paper we present our results on a study ofthe deactivation and characterisation of FCC catalysts, together with product yields at realistic coke levels (0.5 to 1.0%), that are typically found on FCC catalysts during industrial operation. In particular, the effect of quinoline and phenanthrene as additives to the n-hexadecane feedstock has been studied at two concentration levels and the relative roles ofthese additives as catalyst poison and coke inducer are discussed. A further aspect investigated is the influence of catalyst formulation. Pure zeolites are seldom used as FCC catalysts instead, catalysts comprise a number of components, which apart from the zeolite, may include matrix, binder and clay. In the present work, catalyst formulations ranging fi"om 100% matrix to 100% zeolite have been examined and the influence ofthe various catalyst compositions on product distribution and coke formation is assessed. 

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