Formation of Fly Ash Catalysts and Selection of a Matrix Binder and Its Application in Denitration

Abstract

The development of high-efficiency and low-cost new catalysts is an extremely attractive topic. In this study, two different matrix bentonite-modified fly ash catalysts were successfully prepared, and the compressive strength of the catalyst was studied by using unsaturated dynamic and static triaxial technology. The axial compressive strength of FC (fly ash catalysts added with Ca-based bentonite) was greater than that of FN (fly ash catalysts added with Na-based bentonite). The catalyst reached 978 kPa. The prepared catalyst was characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and specific surface area analysis (BET) of the catalyst. In addition, denitration performance of different catalysts was explored, and the reaction conditions were optimized. The results demonstrate that when the mixing ratio of fly ash and calcium-based bentonite in the FC is 4:1, the compressive strength is relatively high, and the denitration rate reaches about 82%.

Remediation of Azure A Dye from Aqueous Solution by Using Surface-Modified Coal Fly Ash Extracted Ferrospheres by Mineral Acids and Toxicity Assessment

“…The crystallinity and composition of ferrous particles depend on the melting point and thermal conditions of microparticle formation [20]. The ferrous particles extracted from CFA find applications in ferrous-dependent industries [21], steel-based industries, coke-smelting industries [22], fillers [23], petroleum cracking [24], catalysis for profound oxidation [25], oxidative coupling of CH 4 (OCM) [26], thermolysis of petroleum residue, adsorbents for environmental clean-up [27], and wastewater treatment [17].…”

Ultrasonication-Assisted Preparation of a Mn-Based Blast Furnace Slag Catalyst: Effects on the Low-Temperature Selective Catalytic Reduction Denitration Process

“…At present, the postcombustion denitration technology is recognized as the more mature and most promising denitration technology, and the most widely used is the vanadium–titanium-type catalyst selective catalytic reduction (SCR) denitration technology. 23 , 24 However, it has some disadvantages, such as a narrow active temperature window (280–450 °C), high catalyst toxicity, and deposition of ammonium nitrate. 25 , 26 Therefore, it is of great significance to develop catalysts with low-temperature activity, weak catalyst toxicity, and high catalytic efficiency.…”

“…NO x control technology includes denitration before combustion, denitration during combustion (low excess air, segmented combustion, flue gas recirculation, and low NO x combustion) and denitration after combustion (selective noncatalytic reaction, nonselective catalytic reaction, electric beam radiation, selective catalytic reaction, and absorption method). − The first two technologies have not been used in the actual production process due to their high cost or poor NO x reduction effect. At present, the postcombustion denitration technology is recognized as the more mature and most promising denitration technology, and the most widely used is the vanadium–titanium-type catalyst selective catalytic reduction (SCR) denitration technology. , However, it has some disadvantages, such as a narrow active temperature window (280–450 °C), high catalyst toxicity, and deposition of ammonium nitrate. , Therefore, it is of great significance to develop catalysts with low-temperature activity, weak catalyst toxicity, and high catalytic efficiency.…”