Optical and structural properties of Mn doped CaSO4 powders synthesized by sol-gel process

Kettab, Ahmed; Mahi, Khaled; Mostefa, Rabah; Badaoui, M.; Mameche, Abderrezak; Kadri, Dahane

doi:10.1016/j.jallcom.2016.07.040

Cited by 20 publications

(5 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 1(b) depicts the spectrum of the samples after thermal treatment, which was compared with that of Raw CS. The peaks observed at 515, 594, 613, and 677 cm −1 were attributed to the v4 bending vibrations of SO 4 2− , indicating that CaO reacted with mineral sulfide to form CaSO 4 , [37] coinciding with the results of XRD. Peaks at around 478 cm −1 were ascribed to the M−O vibration, [38] while peaks at 796 cm −1 and 850–880 cm −1 were assigned to Si−O−Si vibration [39] .…”

Section: Resultssupporting

confidence: 76%

Simultaneous Removal of NOx and SO₂ from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

Wang,

Li,

Wang

et al. 2024

ChemistrySelect

View full text Add to dashboard Cite

In this study, Response Surface Methodology (RSM) was employed to optimize the experimental factors influencing the simultaneous removal of NOx and SO2 in a spray tower wet scrubbing experiment. Thermally modified copper slag (CS‐CaO‐900) was prepared by heat treating the original copper slag. The performance of CS‐CaO‐900 in the synchronized removal of NOx and SO2 was then evaluated in an expanded experimental setup. Based on single‐factor experimental results, the Box‐Behnken design of RSM was used to optimize the reaction parameters in a two‐stage sequential reactor (bubbling reactor + spray tower). NOx removal efficiency was modeled as a function of reaction temperature, pH, and H2O2 concentration. Regression curves provided a visual representation of the interaction effects among these parameters on NOx removal efficiency in the thermally modified copper slag/H2O2 composite slurry. This study elucidates the characteristics of each parameter under wet scrubbing conditions and provides essential data for industrial applications.

show abstract

Section: Resultssupporting

confidence: 76%

Simultaneous Removal of NOx and SO₂ from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

Wang,

Li,

Wang

et al. 2024

ChemistrySelect

View full text Add to dashboard Cite

show abstract

“…The XRD patterns of the fresh Co x O y /MgO samples show the characteristic diffraction peaks of MgO at 2θ = 36.9, 42.9, 62.2, 74.6, and 78.6° (Figure S1a). The characteristic peaks of Co 3 O 4 and CoO are not visible, as they overlap with those of MgO. , HRTEM and STEM–EDS images of 15% Co x O y /MgO show that cobalt oxide particles are highly dispersed over the support (Figures and ). The average size of cobalt oxide nanoparticles was 27.7 ± 11.5 nm.…”

Section: Results and Discussionmentioning

confidence: 99%

CO₂ Hydrogenation at Atmospheric Pressure and Low Temperature Using Plasma-Enhanced Catalysis over Supported Cobalt Oxide Catalysts

Ronda‐Lloret

Wang

Oulego

et al. 2020

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

CO 2 is a promising renewable, cheap, and abundant C1 feedstock for producing valuable chemicals, such as CO and methanol. In conventional reactors, because of thermodynamic constraints, converting CO 2 to methanol requires high temperature and pressure, typically 250 °C and 20 bar. Nonthermal plasma is a better option, as it can convert CO 2 at near-ambient temperature and pressure. Adding a catalyst to such plasma setups can enhance conversion and selectivity. However, we know little about the effects of catalysts in such systems. Here, we study CO 2 hydrogenation in a dielectric barrier discharge plasma-catalysis setup under ambient conditions using MgO, γ-Al 2 O 3 , and a series of Co x O y /MgO catalysts. While all three catalyst types enhanced CO 2 conversion, Co x O y /MgO gave the best results, converting up to 35% of CO 2 and reaching the highest methanol yield (10%). Control experiments showed that the basic MgO support is more active than the acidic γ-Al 2 O 3 , and that MgO-supported cobalt oxide catalysts improve the selectivity toward methanol. The methanol yield can be tuned by changing the metal loading. Overall, our study shows the utility of plasma catalysis for CO 2 conversion under mild conditions, with the potential to reduce the energy footprint of CO 2 -recycling processes.

show abstract

“…Near the band gap, parameters such as the absorption coefficient, reflectivity, index of refraction, and Raman scattering coefficient at the anti‐Stokes and Stokes wavelengths may be different and can vary with temperature, leading to large errors when computing temperature . However, given that calcium sulfate's band gap at 315 nm (3.94 eV) is significantly above 532 nm (2.33 eV), these parameters are expected to be similar . Additionally, the detector must demonstrate a linear response of signal intensity to light intensity, which was verified.…”

Section: Introductionmentioning

confidence: 85%

A comparison of pulsed and continuous lasers for high‐temperature Raman measurements of anhydrite

Kirtley

Leichner

Anderson

et al. 2018

J Raman Spectroscopy

View full text Add to dashboard Cite

Oxygen carrier particles (OCPs) serve as fuel oxidant in emerging chemical looping combustion systems. However, chemical looping combustion process optimization is hindered by the lack of online sensors for measurements of OCP oxidation states at temperatures up to 1,000 °C and pressures up to 10 atm. We are investigating Raman spectroscopy as a potential solution, as this technique is known for its ability to provide noninvasive, molecularly specific information in real time in a wide variety of applications. As a case study, Raman spectra from high‐temperature (>1,000 °C) anhydrite, a potential OCP, are presented using pulsed and continuous wave excitation at 532 nm. When pulsed excitation is coupled with time‐gated detection, background signal from thermal radiation can be significantly reduced from single pulse spectra, outperforming results using an ungated detector. Also, laser heating of the sample is not observed but laser‐induced breakdown spectra increasingly appear with increasing temperature and pulse intensity. Compared with pulsed excitation, continuous wave excitation with longer acquisition time, offers higher signal to noise and avoids the risk for laser‐induced breakdown spectra but demonstrates minor sample heating. Finally, the data demonstrate practical utility by (a) providing a calibration of anhydrite's ν1 (1,017 cm−1) Raman temperature‐dependent band position and by (b) providing estimates of temperature using the ratios of the Stokes/anti‐Stokes ν1 integrated intensities. These results demonstrate the first high‐temperature, pulsed Raman spectra from anhydrite while evaluating challenges associated with high‐temperature, Raman measurements of OCP materials in general.

show abstract

Optical and structural properties of Mn doped CaSO4 powders synthesized by sol-gel process

Cited by 20 publications

References 29 publications

Simultaneous Removal of NOx and SO₂ from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

Simultaneous Removal of NOx and SO₂ from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

CO₂ Hydrogenation at Atmospheric Pressure and Low Temperature Using Plasma-Enhanced Catalysis over Supported Cobalt Oxide Catalysts

A comparison of pulsed and continuous lasers for high‐temperature Raman measurements of anhydrite

Contact Info

Product

Resources

About

Optical and structural properties of Mn doped CaSO4 powders synthesized by sol-gel process

Cited by 20 publications

References 29 publications

Simultaneous Removal of NOx and SO2 from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

Simultaneous Removal of NOx and SO2 from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

CO2 Hydrogenation at Atmospheric Pressure and Low Temperature Using Plasma-Enhanced Catalysis over Supported Cobalt Oxide Catalysts

A comparison of pulsed and continuous lasers for high‐temperature Raman measurements of anhydrite

Contact Info

Product

Resources

About

Simultaneous Removal of NOx and SO₂ from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

Simultaneous Removal of NOx and SO₂ from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

CO₂ Hydrogenation at Atmospheric Pressure and Low Temperature Using Plasma-Enhanced Catalysis over Supported Cobalt Oxide Catalysts