Novel SO x removal catalysts for the FCC process: Manufacture method, characterization, and pilot-scale testing† Jaime S. Valente * and Roberto Quintana-Solorzano Received 21st February 2011, Accepted 8th July 2011 DOI: 10.1039/c1ee01197a A novel method for preparing SO x removing (ReSO x ) catalysts for the fluid catalytic cracking (FCC) process, based on multimetallic layered double hydroxides (LDHs), is presented. The synthesis procedure is industrially feasible and environmentally friendly. Ceria is incorporated in varying amounts as oxidation promoter, to obtain catalysts that are able to work efficiently in either partial or full combustion regenerator modes. The manufacturing process presented herein enables obtaining, by spray drying, microsphere particles with mechanical properties that are adequate for fluidization, without requiring addition of binding agents. The physicochemical properties of the catalysts are examined by several characterization techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). A uniform dispersion of the metal components is observed throughout the particles. Furthermore, the microspheroidal catalysts are tested for the reduction of SO x emissions in a pilot-scale FCC plant, circulating together with a conventional cracking catalyst, during the conversion of a sulphur-containing industrial gas oil obtained from a Mexican refinery. ReSO x catalyst addition to the pilot FCC unit, in only 0.2 wt% of the total catalyst inventory, results in a maximum %SO 2 reduction of 74–80%. Additionally, the effect of the ReSO x catalyst on the main cracking reactions is studied; it is shown that the disruption of the cracking catalyst’s activity and selectivity is minimal, at a concentration of 1.5 wt% of the total catalyst inventory. Thus, the use of these SO x removal catalysts appears as a viable, low investment, flexible and effective option for in situ reduction of SO x flue gas emissions. 1. Introduction Sulphur oxides, commonly termed SO x , are a mixture of SO 2 and SO 3 , wherein SO 2 is the predominant form found in the lower atmosphere. These noxious gases react with ambient moisture to produce acid rain; they may also adsorb onto fine particulate matter forming sulphate aerosols. The negative effects of SO x are widespread. Short-term human exposure to high concentrations of SO x (above 1000 mgm 3 ) is associated with reduced lung Instituto Mexicano del Petr  oleo, Eje Central # 152, Mexico, D.F., 07730, Mexico. E-mail: jsanchez@imp.mx; sanchezvalente@yahoo.com; Tel: (+52) 55 9175 8444 † Electronic supplementary information (ESI) available: Reactant amounts employed for the synthesis of each catalyst, details on the characterization techniques, physicochemical properties of the main cracking catalyst E-CAT, and methods for determination of flue gases and cracked products. See DOI: 10.1039/c1ee01197a Broader context SO x are noxious air pollutants closely linked to industrial activities. About 90 wt% of total SO x emissions are released from power plants, chemical industries and crude oil refineries. In the latter, fluid catalytic cracking (FCC) units aimed at converting sulfur containing gas oils to yield high value automotive fuels are the main source of SO x , which are discharged to the atmosphere in the regenerator. A low investment, flexible and effective option for in situ abating SO x in FCC is the usage of special SO x -removing (ReSO x ) catalysts. This work claims a simple, environmentally friendly and industrially feasible novel method to prepare multi- metallic layered double hydroxide-based ReSO x catalysts. They are flexible and suitable to be used in both partial and full combustion regenerators by varying the amount of ceria, an oxidation promoter. FCC pilot-scale experiments over ReSO x catalysts in the form of microspherical bodies, produced without adding binding agents, show that SO x discharges are efficiently removed. Pilot plant results, i.e. feed conversion and products distribution, reveal that the effect of ReSO x catalyst addition on main cracking is minimal. Obtained results suggest that novel ReSO x catalysts have a high potential to be applied at the industrial scale. This journal is ª The Royal Society of Chemistry 2011 Energy Environ. Sci. Dynamic Article Links C < Energy & Environmental Science Cite this: DOI: 10.1039/c1ee01197a www.rsc.org/ees PAPER Downloaded by Universidad Autonoma Metropolitana-Iztapalapa on 12 August 2011 Published on 11 August 2011 on http://pubs.rsc.org | doi:10.1039/C1EE01197A View Online