Application of Design of Experiments to the Alkaline Treatment in Mordenite Zeolite: Influence on Si/Al Ratio

Abstract:

This paper presents the application of Design of Experiments (DOE) to an alkaline treatment in mordenite zeolite, in order to identify the optimum settings of the variables (temperature and concentration of NaOH) that promote greater desilication. Samples of commercial mordenite with Si / Al ratio = 9 have been treated with aqueuos NaOH solution of various concentration (0,1;0,5;1,0) and temperature (30,50,70°C). Statistical analysis was carried out based on a 2² factorial design with center point replicates. Seven experiments were executed and the data of Si/Al ratio obtained. The resulting samples were characterized by x-ray difraction (XRD) and energy dispersive x-ray (EDX), to identify the structures and crystalline phases, and to determine the percentages of silicon and aluminum, respectively. In all samples, a decrease in the Si / Al ratio was observed, keeping the crystalline structure. The treatment was most effective, especially, at high temperature and NaOH concentration (experiment 4). DOE was shown to be a powerful techinique for the study of the variables, allowing determining which variables and value ranges have more influence on response, enabling optimization.

• Periodical: Materials Science Forum (Volumes 798-799)
• Pages: 435-440
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.798-799.435
• Online since: June 2014
• Authors: Heloísa Pimenta de Macedo*, Lívia Cristina de Oliveira Felipe, L.B. Silva, Laurenia M. Pereira Garcia, R.L.B.A. Medeiros, T.R. Costa
• Keywords: Alkaline Treatment, Design of Experiment (DOE), Mordenite, Si/Al Ratio

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