Zeolite from fly ash: synthesis and characterization

Abstract

Coal fly ash was used to synthesize X-type zeolite by alkali fusion followed by hydrothermal treatment. The synthesized zeolite was characterized using various techniques such as X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, BET method for surface area measurement etc. The synthesis conditions were optimized to obtain highly crystalline zeolite with maximum BET surface area. The maximum surface area of the product was found to be 383 m 2 /g with high purity. The crystallinity of the prepared zeolite was found to change with fusion temperature and a maximum value was obtained at 823 K. The cost of synthesized zeolite was estimated to be almost one-fifth of that of commercial 13X zeolite available in the market.

The conversion technology of fly ash into zeolites

“…Literature and data show that by using appropriate synthesis conditions, coal fly ash can be converted into different zeolite structures such as analcime (Adamczyk and Bialecka 2005;Querol et al 1997;Wang et al 2003), chabazite (Wang et al 2003), cancrinite, gmelinite, Na-P1 (Adamczyk and Białecka 2005;Hollman et al 1999;Wang et al 2003), ZSM-5 (Mohamed et al 2008), ZSM-28 (Wang et al 1998), Na-X (Derkowski et al 2006(Derkowski et al , 2007Querol et al 1997;Tanaka et al 2002), Na-Y (Ojha et al 2004), philipsite (Querol et al 1997), and sodalite (Musyoka et al 2011).…”

Batch and Column Adsorption of BOD and COD in Vegetable Oil Industry Effluents Using Activated Carbon from Fluted Pumpkin (<i>Telfairia, Occidentalis.</i> Hook. F) Seed Shell

“…FAC 3 and FAC 5 showed higher reduction in BOD both at initial stage and final stage. While FAC 1 and FAC 2 showed anomalies; but it should be noted that all five PFACs showed similar reduction in BOD at the initial stage and again, [28] suggested an explanation to this that more active surfaces available for adsorption at the initial stage and towards the end of the experiment-longer contact time, the active sites are consumed and are less available COD reduced steadily with time for FAC 3 and FAC 5 Figure 4 shows the effect of varying carbon dose on BOD in a batch process. Four PFAC showed poor adsorption while FAC 3 showed better adsorption; the adsorption was similar for all PFACs.…”

“…The fifth hours may correspond to equilibrium time. [28] explains that this may be due to the fact that initially a large number of vacant sites were available for adsorption which progressively became smaller with time. Figure 2 shows the effect of contact time on COD for 1gs of FFAC in a batch system in terms of COD.…”

Conversion of South African Coal Fly Ash into High-Purity ZSM-5 Zeolite without Additional Source of Silica or Alumina and Its Application as a Methanol-to-Olefins Catalyst

“…Several routes to prepare various zeolite types have been suggested based on the pre-treatment of the fly ash, alkalinity of the hydrothermal solution, molarity of alkaline agents, solution/solid ratio, templating agent, time, temperature and time of incubation [2][3][4][5][6][7][8][9]. ZSM-5 is synthesized from a hydrothermal solution containing Al and Si sources, a mineralizing agent (OH − or F − ) and an organic structure-directing agent (OSDA) [10][11][12][13], with tetrapropylammonium cation (TPA + ) being the most-used OSDA [9,[14][15][16].…”