Papers by Keyword: Calcination Temperature

Paper TitlePage

Authors: Si Yuan Wu, Hong Zheng, Peter G. Weidler, Peng Cai
Abstract: With synthetic wastewater, a comparative study on co-sorption of Zn(II) and As(V) by Fe/Al-PILCs prepared at different calcination temperatures was investigated using a lab-scale batch experiment technique. The effects of relevant parameters, such as pH value of solution, adsorbent dosage and contact time were examined, respectively. The results show that sorption efficiencies of Zn(II) and As(V) by Fe/Al-PILC prepared at calcination temperatures of 300 °C are higher than those at 350 and 400 °C and the higher calcination temperature is, the lower sorption efficiencies of Zn(II) and As(V) are. Co-sorption isotherm data of Zn(II) and As(V) by Fe/Al-PILCs were fitted well to Langmuir isotherm and the maximum sorption capacities of Zn(II) and As(V) on Fe/Al-PILC (Q0) prepared at 300 °C are 13.95 and 15.87 mg/g, respectively, which are higher than those at calcination temperatures of 350 °C and 400 °C. The maximum sorption capacity of As(V) decreases more obviously with increasing calcination temperature than Zn(II) does. n>1 from Freundlich isotherm indicate that the sorption of Zn(II) and As(V) by Fe/Al-PILCs is favorable. E values from D-R model indicate that the type of sorption of Zn(II) and As(V) by Fe/Al-PILCs is physical. There is significant potential for Fe/Al-PILC prepared at calcination temperature of 300 °C as an adsorbent material for Zn(II) and As(V) removal from aqueous solutions.
Authors: Zong Wu Wei, Jian Hua Chen, Mei Qun Lin, Ye Chen
Abstract: TiO2 pillared rectorite (TPLR) had been synthesized by sol-gel method, and was characterized by XRD, TEM, BET, UV-vis DRS and FTIR. The effects of calcination temperature on the microstructure and the photocatalytic activity of the as prepared catalyst were investigated. The photocatalytic activity of the catalyst was evaluated by decomposition of Acid Red B (ARB) aqueous solution. XRD patterns revealed that TiO2 is incorporated into the interlayer of the rectorite. TEM demonstrated that TiO2 particles are present in the rectorite. The BET analysis indicated that the surface area of the sample calcined at 300°C (TPLR-300) was larger than those of other samples. The TPLR samples had high adsorption capacity and good photocatalytic efficiency in decomposition of ARB in water. FTIR spectra of the original and the recovered samples indicated that the catalyst had not chemically changed during the photocatalytic reaction.
Authors: Li Yuan Qin, En Chen Jiang, Yan Sun, Shuang Li
Abstract: Nickel-based catalysts were prepared by impregnating at different calcination temperatures to solve the problems of short lifetime, coking and hard to regenerate of HZSM-5 catalyst which was widely used as bio-oil upgrading catalyst. The NiO loading was 8wt. %, and the calcination temperature was 350~650°C. The surface characteristics, catalytic and regenerative properties of the catalysts were also analyzed and compared. When the calcination temperature is 550 °C, the catalyst shows good properties and the conversion of toluene and guaiacol is 83% and 80% respectively. The results of life-tests show that the adding of active material can help extend the life and improve the anti-coking ability of the catalyst. The conversion of toluene and guaiacol keeps at 40% and 50% respectively after 6h continuously catalytic reaction. The macromolecule aromatics in the catalyst channel can be converted into micromolecule aromatics by the adding of NiO.
Authors: Salmiah Jamal Mat Rosid, Wan Azelee Wan Abu Bakar, Rusmidah Ali
Abstract: The methanation reaction is a promising method for the purification of natural gas, in which the acid gases of CO2, is eliminated by catalytic conversion. The advantage of catalytic technology is the utilization of CO2 present in the production of methane gas. The used of alumina supported cerium oxide as the based catalyst in CO2/H2 methanation reaction have been investigated in this research by using manganese as the dopant and ruthenium as the co-dopant via wet impregnation technique. The series of cerium oxide catalysts were calcined at 400 °C for 5 hours had been prepared at the screening stage. Then, the catalysts were optimized by different calcination temperatures and different based oxide loadings. The potential catalysts of Ru/Mn/Ce (5:35:60)/Al2O3 calcined at 700 °C gave 100 % of CO2 conversion by using FTIR and yielded about 24 % of CH4 respectively at reaction temperature of 400 °C. X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM) showed that the supported catalysts were amorphous in structure. FESEM analysis illustrated the surface of the catalysts were covered with small and dispersed spherical particles. EDX analysis revealed that there was 1.02 % reduction of Ru in the Ru/Mn/Ce (5:35:60)/Al2O3 used catalysts compared to fresh catalysts. Meanwhile NA analysis showed that Ru/Mn/Ce (5:35:60)/Al2O3 catalysts attained surface area of 143.10 m2/g respectively.
Authors: Noor Yahida Yahya, Norzita Ngadi
Abstract: Currently, the major concern in production of biodiesel is to find a new catalyst which can produce high quality of biodiesel at lower costs. In this study, titania supported CaO catalyst was prepared by a so-gel method. The characterization of catalyst was done using Brunauer-Emmett-Teller (BET) model method to characterize the surface area of the catalyst. Further, the ability of the catalyst for transterification reaction of waste cooking oil (WCO) with methanol was also assessed. The effect of calcination temperature on the catalyst to the transesterification reaction was examined to investigate the relation between catalyst calcination temperature and percentage yield (% yield) of biodiesel production.
Authors: Renugambaal Nadarajan, Wan Azelee Wan Abu Bakar, Rusmidah Ali
Abstract: The effects of calcination temperature on the microstructures and photocatalytic activity of sol-gel synthesized TiO2, WO3, SnO2 and ZnO metal oxides were investigated. The synergistic effect of the phase structure, surface area, and crystallinity of the photocatalysts after calcination and on the photocatalytic activity was investigated. 1,2-dichlorobenzene (DCB) was used as a model contaminant in this study. The highest photocatalytic activity was obtained using TiO2 calcined at 900oC with large particle size, could be ascribed to the enhancement by the presence of defect site. Similarly, WO3 calcined at 900oC exhibited the best photocatalytic activity in the series of calcination temperature ranging from 400-1000oC. SnO2 calcined at 800oC showed the best photocatalytic activity while ZnO was found to give the lowest percent of DCB degradation. In this study, sudden increase in the surface area at higher temperature was correlated with the enhancement in the photocatalytic activity of each catalyst.
Authors: Jian Xin Cao, Fei Liu, Qian Lin, Yu Zhang, Yong Gang Dong, Ling Ke Zeng
Abstract: The calcined carbide slag was used to prepare xonotlite by replacing quicklime as the calcareous materials. Effects of calcination temperature on the mineral composition of the carbide slag, lime activity and synthesized xonotlite were studied. The results indicated that carbide slag after proper calcination can be used to prepare xonotlite. Calcination temperature has no effect on the synthesized xonotlite, but has a great impact on lime activity and morphology of secondary particles of xonotlite.
Authors: Arman Sikirman, Jagannathan Krishnan
Abstract: Effect of calcination temperature on the synthesis of N, Fe codoped TiO2 for the photodegradation of methylene blue under ordinary visible lamps was investigated. The photocatalyst were prepared using solgel method where titanium isopropoxide was used as precursor of titania. The calcination temperatures were varied from 450 to 600°C. The prepared photocatalysts were characterized by using XRD, FE-SEM and FTIR to determine their physical properties. The results from XRD proved that photocatalysts calcined at 600°C possessed perfect properties in phase and crystal size. FE-SEM image analysis revealed the formation of the fine spherical particles and the FTIR analysis verified the presence of dopants at various calcination temperatures. The effectivity of photocatalysts was tested by performing a standard batch photocatalytic degradation experiment with methylene blue as a model pollutant under ordinary visible light. The result showed that N and Fe codoped photocatalyst calcined at 600°C (1.0 % N, Fe-TiO2-600) yielded a maximum of 80.50% methylene blue degraded within five hours of irradiation time.
Authors: Mohd Fariz Ab Rahman, Mohamad Johari Abu, Rosyaini Afindi Zaman, Julie Juliewatty Mohamed, Mohd Fadzil Ain, Mohamad Kamarol Mohd Jamil, Zainal Arifin Ahmad
Abstract: The effect of calcination temperature on the breakdown strength and energy density of CaCu3Ti4O12 (CCTO) ceramics was studied. CCTO ceramics were prepared via solid state reaction method. The raw materials of CCTO were wet mixed for 24 hours and then dried overnight in oven. CCTO mixtures were calcined at three different temperature which is at 900°C, 930°C and 950°C for 12 hours. The calcined powders were compacted at 250 MPa and then were sintered at 1040°C for 10 hours. X-Ray Diffractometer (XRD) analysis showed the formation of CCTO phase and secondary phases of CuO and CaTiO3 for C900 calcined powders but single phase of CCTO was obtained by C930 and C950 calcined powders. Single phase of CCTO also were seen for all sintered samples. Observation on Scanning Electron Microscopy (SEM) micrographs showed large grain size was seen in C900 sintered sample and finer grain size was observed for C930 and C950 sintered samples. C900 sintered sample obtained highest dielectric constant (8617), highest breakdown strength (7.92 kV/cm), highest energy density (2.392 J/cm3).
Authors: Li Wu Mo, Min Deng, Ming Shu Tang
Abstract: Shrinkage compensating by the expansion generated by the hydration of expansive additive is one of the important measures to improve the dimensional stability of cement-based materials. Due to the slow hydration of MgO, it may cause delayed expansion in cement and thus has been used as an expansive additive to compensate thermal shrinkage at late age in mass concrete. The relationship among the microstructure, activity and expansion properties of MgO-type expansive additive (MEA) has not been clearly demonstrated, though many researches have been focused on its expansion mechanism and expansion properties. So the industrial production and application of MEA depend much on empirical methods. Three different types of MEA are produced by calcining magnesite at 900°C, 1100°C, and 1300 °Cfor 1h in an electrical furnace. The specific surface area, activity, inner pore structure, microtopography and expansion properties of the MEA have been investigated. Results show the effect of calcination temperatures on the expansion properties of MEA results from the changes in its microstructure, specific area, and thus the activity. High calcination temperature causes growth in MgO grain, decrease in specific area and surface defects of MgO, and hence the reduction of the activity value, inducing slow hydration rate and thus delayed expansion. This study will provide a platform for well understanding various activity and expansion properties of MEA produced under different temperatures.
Showing 1 to 10 of 45 Paper Titles