Synthesis of zeolites from fly ash with the use of modified two-step hydrothermal method and preliminary SO₂ sorption tests

Abstract

Synthesis of zeolites from fly ash is an ecologically justified process aimed at the transformation of energy sector waste – fly ash into microcrystalline zeolites of broad possible application field. In this study, the synthesis of zeolites from fly ash by using a modified two-step synthesis was presented. The aim of such a planned experiment was to use the waste solutions from previous synthesis, in such a way that minimalization of negative influence of post-synthesis wastes on environment was possible. Received materials were tested for its sulfur dioxide sorption capacity, indicating its future possible application to capture SO2 from exhaust gases.

Synthesis and Characterization of Zeolites Produced from Low-Quality Coal Fly Ash and Wet Flue Gas Desulphurization Wastewater

“…The typical pH spectrum observed during zeolite synthesis experiments (when the NaOH solution was applied), ranged from 13 to 13.3. This is a typical value for hydrothermal zeolite synthesis from coal fly ash [ 44 , 45 ]. To determine whether it is possible to synthesize zeolite from low-quality CFA under the chosen conditions, all the collected samples were subjected to XRD measurements.…”

Heavy Metal Removal from Aqueous Solutions Using Fly-Ash Derived Zeolite NaP1

“…Zeolite X and A are in high demand due to their uniform pore structure and larger pore size, compared to NaP1 (Alvarez-Ayuso et al 2003), sodalite and chabazite. However, fly-ash derived zeolites X and A are more expensive to synthesize, compared to NaP1, through the conventional hydrothermal synthesis process as they require large quantities of raw materials (aluminate, silicon and NaOH) and a 2-step process (Czuma et al 2019). Fly-ash derived NaP1 can be produced with a high yield (45-75%), compared to fly-ash derived zeolites X and A (16-18%) in a one-step process using low amount of raw materials (Moreno et al 2001;Querol et al 2001).…”

Coal fly ash driven zeolites for the adsorptive removal of the ceftazidime drug

“… 4 In the context of fly ash, China is one of the biggest coal consumers and producers, with an annual CFA production of 7.8 × 10 8 metric tons. 14 The large quantity of annually produced CFA is primarily utilized for construction purposes, such as road sub-base material. However, the utilization efficacy remains low based on CFA's granular inconsistency.…”