Multitechnique Characterization of Coke Produced during Commercial Resid FCC Operation

Abstract

The characterization of industrial coked resid fluid catalytic cracking (RFCC) catalysts is reported. The aim is to provide insight into the coke deposition on commercial resid fluid catalytic cracking catalysts sampled after the stripper of a commercial RFCC unit and to relate it to the potential process chemistry. Physicochemical techniques were used to characterize the used catalysts and the deposited coke. 95% of the coke was insoluble in CH2Cl2. This coke was located in the mesopores of the catalyst matrix. The results suggest the existence of domains of polyaromatic and heterogeneously distributed coke, in which saturated hydrocarbons are trapped. IR spectroscopy of adsorbed pyridine shows that the largest fraction of strong Brønsted acid sites is free after the catalyst has passed the stripper. The results indicate that for RFCC not the local deactivation of the acid sites but rather blocking of domains of the catalyst is the most important mode of deactivation after passing through the riser reactor.

Probing the Different Life Stages of a Fluid Catalytic Cracking Particle with Integrated Laser and Electron Microscopy

“…Examples include atomic force microscopy (AFM), [4][5][6] scanning electron microscopy (SEM), [7][8][9][10][11][12] and transmission electron microscopy (TEM). [13][14][15][16][17] These methods provide high-resolution detail, but no correlation was possible between the structure and the activity of the investigated catalyst particles. Recently, various chemical imaging methods have been introduced that allow identifying the intra-and interparticle heterogeneities of catalyst materials.…”

Recent Advances in the Chemical Recycling of Polymers (PP, PS, LDPE, HDPE, PVC, PC, Nylon, PMMA)

“…These studies assay reactions such as the cracking of hydrocarbons (Cerqueira et al, 2005;, Guisnet et al, 2009). Marcilla et al studied the deactivation of zeolites during the cracking of high-density polyethylene (HDPE), by using mainly a thermobalance as reactor.…”

Cracking and Hydrocracking

“…The alkanes and alkenes are mostly branched; the branched alkenes and the aromatics contribute most to the high octane number. Examples of product compositions are given in Figure 18.4 [21,22]. An FCC unit operator faces a changing market and changing environmental restrictions, some of which concern us here:…”

“…The share of FCC-produced propene is 100 Figure 18.4 FCC product slate: historical development through improved catalysts [12] (left), and some typical detailed compositions from PIONA [21] GCxGC and MALDI-TOF [22] (right). expected to grow from roughly a quarter to roughly a third of world propene production in 2015 [23].…”

“…22 Deactivation rates of amorphous and zeolite catalysts in the hydrocracking of a hydrotreated vacuum gas oil[126].…”