LCA Method of MSC and Low-NOx Burner Technology in Cement Manufacturing

et al. 2020

MSF

Self Cite

In order to deal with the pollution of NO in cement kiln exhaust, the study of NO catalytic decomposition catalyst obtained much more attention. The effect of silica-alumina ratio on NO decomposition rate in cement kiln without other reductant was studied. The NO decomposition rate of catalysts with different silica-alumina ratio was determined by infrared spectrometer. And pore structures and the microstructure of the catalyst were characterized separately by BET surface area, nitrogen adsorption-desorption and XRD. The results show that silica-alumina ratio of catalyst was preferred to be 50 with the best NO decomposition rate when the temperature was below 300 °C. The catalyst with silica-alumina ratio of 60 has the higher catalytic activity when the temperature was higher than 300 °C, and the decomposition rate achieved 70% at 600 °C. XRD results shows the crystallinity of catalysts increased as the silica-alumina ratio increased. BET surface area and the cumulative pore volume of catalysts gradually increased, and the average pore diameter gradually reduced with the increase of silica-alumina ratio.

Section: Introductionmentioning

confidence: 99%

Effect of Silica-Alumina Ratio of Catalysts on NO Decomposition Rate in Cement Kiln Exhaust

Gan

et al. 2020

MSF

Self Cite

“…At present, denitrification technologies that usually be applied to cement kilns include low NOx combustion technology [12], selective catalytic reduction (SCR) [13,14], and selective non-catalytic reduction (SNCR) [15]. Thermal NOx formation can be decreased by approximately 30% after low NOx combustion technology [16,17], so the efficiency of low NOx combustion technology is too low to meet the emission standard of air pollutants for cement industry. The selective non-catalytic reduction technology (SNCR) is relatively simple and cost-effective technology for removing NOx.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Cu-Al/SiO2 Porous Material and Its Effect on NO Decomposition in a Cement Kiln

Gan

et al. 2019

Materials

Nitrogen oxide (NOx) emissions have attracted much attention for increasing concern on the quality of the atmospheric environment. In view of NO decomposition in the cement production process, the preparation of Cu-Al/SiO2 porous material and its effect on NO decomposition were studied, and the denitrification mechanism was proposed in this paper. The NO decomposition performance of the Cu-Al/SiO2 porous material was tested via the experimental setup and infrared spectrometer and micro gas chromatography (GC). The result shows that the Cu-Al/SiO2 porous material with the template of cetyltrimethylammonium bromide (CTAB) had a better NO decomposition rate than materials with other templates when the temperature was above 500 °C, and NO decomposition rate could approach 100% at high temperatures above 750 °C. Structure analysis indicates that the prepared Cu-Al/SiO2 material structure was a mesoporous structure. The X-Ray Diffraction (XRD) and Ultraviolet–visible spectrophotometry (UV–Vis) results of the denitrification product show that the Cu-Al/SiO2 material mainly decomposed to Cu2O and Si2O, and the CuO decomposed to Cu2O and O2 at high temperature. The Cu(I)O was considered as the active phase. The redox process between Cu(II)O and Cu(I)O was thought to be the denitrification mechanism of the Cu-Al/SiO2 porous material.

“…Selective catalytic reduction (SCR) is the most effective technology for post-combustion removal of NO x , and the catalytic material is the key to SCR technology. At present, Mn/TiO 2 catalyst is widely studied due to considerable activity in the SCR of NO x at low temperaturesto avoid reheating the stack gas, high conversion of SO 2 to SO 3 associated with the existing commercial catalytic system [1][2][3][4][5]. NO conversion of the MnO x -based catalystsat 100-250℃ NH 3 -SCR was enhanced by the doped metal cations [6].…”

Section: Introductionmentioning

confidence: 99%

Different Precipitant Preparation of Nickel-Doped Mn/TiO<sub>2</sub> Catalysts for Low-Temperature SCR of NO with NH<sub>3</sub>

Wang

Guo

et al. 2018

MSF

Self Cite

The Mn-Ni/TiO2 catalyst was prepared by co-precipitation method and investigated for the low-temperature selective catalytic reduction (SCR) of NO with NH3 in this work, and Mn-Ni/TiO2 catalysts were prepared by different precipitants respectively such as sodium hydroxide, carbamide, ammonia or hydrogen peroxide. The microstructure and performance of catalysts were investigated. The activitiesof catalysts prepared by different precipitants were studied in the temperature range 90°C-350°C. The results show that Mn-Ni/TiO2catalyst prepared by CO(NH2)2-NH3·H2O-H2O2 compound precipitant has an extraordinary performance even at the low temperature of 120°C. H2-TPR results show the peak positions shift to lower temperatures, standing for the reduction potential of MnOx species is increased compared to those of Mn/TiO2 catalysts. The interaction of Ni and Mn atoms is beneficial to an enhancement of the oxygen mobility due to CO(NH2)2-NH3·H2O-H2O2 as precipitant. It is worth noting that the low temperature peak area increased by adding hydrogen peroxide as precipitant. NH3-TPD results illustrat that for the Mn/TiO2 and Mn-Ni/TiO2 catalysts which are attributed to NH3 desorbed by weak acid sites and Brønsted acid sites.