AM-10-167 The Benefits of Cat Feed Hydrotreating and the Impact of Feed Nitrogen on Catalyst Stability

Description:

This paper deals with the objectives and constraints of pretreating feedstocks for fluid catalytic cracking. It will look at the chemistry involved and, based upon new insights, will consider feed nitrogen and its impact on the selection of catalyst type for the most stable performance. Currently, there is a growing need to refine heavier and tougher crude oils with an increased nitrogen content and other contaminants such as polyaromatics, metals, arsenic and silicon. Therefore, not only hydrodesulfurization (HDS) is very important, but also hydrodenitrogenation (HDN) has become a critical hydroprocessing reaction which provides more insight into catalyst stability. In the present paper, we discuss the different nitrogen compounds found in high nitrogen feedstocks to FCC pretreat which we have identified using gas chromatography with atomic emission detection (GC-AED). Our findings can be related to several studies using model feedstocks which show that in particular basic nitrogen-containing molecules inhibit HDS reactions the most. We will discuss factors that impact the catalyst stability, and finally we will show data from industrial units.