459898 Thiophenic Species Removal over a New Zn-Offretite Zeolite Via Selective Adsorption for FCC Processes

Monday, November 14, 2016: 2:05 PM
Franciscan D (Hilton San Francisco Union Square)
Yira Aponte, Chemical and Biochemical Engineering, The University of Western Ontario, London, ON, Canada and Hugo de Lasa, Chemical Reactor Engineering Centre, Western University, London, ON, Canada

This study considers the sulfur selective adsorption of a new Zn-Offretite zeolite based additive under FCC conditions. This Zn-Offretite (Zn-OFF) zeolite was prepared via direct inclusion of zinc in the OFF synthesis. The goal is to obtain a sorbent suitable for thiophenic chemical species removal via selective adsorption under FCC conditions. Physicochemical characterizations combined with reactivity studies were developed to understand the adsorption process. It was proven that the introduction of Zn in the OFF zeolite considerably increases acidity and Lewis/Brönsted acid site ratio. These two properties promote the thiophenic selective adsorption in the OFF structure. The valuable performance of the Zn-OFF additive was demonstrated in a CREC Riser Simulator unit under typical FCC conditions. Reactivity studies showed that the Zn-OFF additive is a suitable sorbent for thiophenic species adsorption with an optimum operation at 5s and 530°C. It was found that the Zn-OFF in combination with a FCC commercial catalyst can reach 51 wt% of 2-methyl-thiophene reduction with only 2wt% of sulfur left as coke. In addition, and when the FCC catalyst was blended with 5-15wt% of 3.5Zn-OFF, it yielded a 210% coke reduction. On the basis of the above, it is demonstrated that the Zn-OFF additive can contribute to both selective adsorption of sulfur containing species and lower coke. This reduced coke may become a significant Zn-OFF additive feature for mitigating SOx emissions in the FCC regenerator.

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See more of this Session: Environmental Catalysis: Air Pollution Control
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