Acidic Removal of Metals From Fluidized Catalytic Cracking Catalyst Waste Assisted by Electrokinetic Treatment

Abstract

-One of the main uses of catalysts in the oil industry is in the fluidized catalytic cracking process, which generates large quantities of waste material after use and regeneration cycles and that can be treated by the electrokinetic remediation technique, in which the contaminant metals are transported by migration. In this study, deactivated FCC catalyst was characterized before and after the electrokinetic remediation process to evaluate the amount of metal removed, and assess structural modifications, in order to indicate a possible use as an adsorbent material. The analyses included pH measurement and the concentration profile of vanadium ions along the reactor, X-ray microtomography, X-ray fluorescence, BET analysis and DTA analysis. The results indicated that 40% of the surface area of the material was recovered in relation to the disabled material, showing an increase in the available area for the adsorption. The remediation process removed nearly 31% of the vanadium and 72% of the P 2 O 5 adhering to the surface of the catalyst, without causing structural or thermal stability changes.

Y zeolite equilibrium catalyst waste from fluidized catalytic cracking regenerated by electrokinetic treatment: An adsorbent for sulphur and nitrogen compounds

“…The curves indicate the occurrence of two events: the events are an endothermic process with two temperature peaks and an exothermic process with one temperature peak. As shown in Figure , the first endothermic peak occurred at approximately 113 °C; this peak was attributed to the loss of water molecules or other volatile species located in the cavities of the ecat‐R . A second broad and poorly defined endothermic peak between 300–800 °C has been mentioned in the literature.…”

“…Focusing on materials reuse, the ecat‐R, an equilibrium catalyst (Y zeolite) waste from fluidized catalytic cracking units (FCC units) regenerated by electrokinetic treatment using 1M sulphuric acid, has been studied as an adsorbent. All details of the electrokinetic treatment are described in recent reports by the group of applied electrochemistry (GEA) that provided the material for this study …”

Regeneration study of ecat-R as adsorbent for denitrogenation and desulfurization of diesel fuels

“…The electrokinetic remediation is employed for nickel, vanadium and rare earth cations removal from deactivated ecat and, consequently, to restore the catalytic activity from deactivated ecat - Fig. 1 (stage 2) [3,[9][10][11].…”

“…The electrolytes applied by this technique are sulfuric acid solution and sodium citrate solution [3,4,9,11]. When ecat did not completely lost its catalytic activity the electrokinetic remediation is made with sodium citrate solution (ecat-R-SC).…”

“…However, when the rare earth, nickel and vanadium elements are in critical concentration and ecat completely lost its catalytic activity the chosen solution for electrokinetic remediation is composed by sulfuric acid (ecat-R-SA) [12]. All details of the electrokinetic treatment are described in recent reports by the group of applied electrochemistry (GEA) that provided the material for this study [3,9].…”