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Effect of fortified calcium compounds from oyster shell on the quality of tapioca pearls
(2025-01-15)
Meeparn, Parinda
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Aenglong, Chakkapat
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Ratanasumawong, Savitree
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Klaypradit, Wanwimol
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Kerdpiboon, Soraya
This study aimed to determine the effect of calcium fortification from dried oyster shells (DOS) and calcined oyster shells (COS) at concentrations of 2, 4 and 6 %(w/w) on physical and chemical properties of tapioca pearls. The results showed that the optimal cooking time of TP-COS decreased compared to TP-DOS and TP (control). The TP-DOS and TP-COS exhibited a remaining calcium content ranging from 8.39 to 41.03 mg/g. During seven days of refrigerated storage, TP-COS showed delayed hardness along with decreases in both the enthalpy of gelatinization and retrogradation. The functional groups observed in TP-DOS and TP-COS showed varying intensities compared to TP. Morphology images depicted the distribution of DOS and COS within tapioca pearls, revealing that TP-DOS and TP-COS possessed a denser and more compact structure. The results suggest that COS fortification could improve the nutritional value and delay the change in the texture of tapioca pearls after storage.
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Influence of hydrothermal and calcination process on metakaolin from natural clay
(2018-09-05)
Srilai, Suphada
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Kaewtrakulchai, Napat
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Panomsuwan, Gasidit
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Fuji, Masayoshi
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Eiad-Ua, Apiluck
In this study, metakaolin was synthesized from natural clay from Lampang province via hydrothermal and calcination process. The hydrothermal process was studied at different temperature from 160°C, 180°C and 200°C for 4, 8 and 12 hours. The calcination process was studied at different temperature from 500 to 900°C for 2 hours. Regarding the characterization, physical morphology of resulting products was observed by scanning electron microscope showing that the surface of resulting product was enhanced its surface area with more roughness when the temperature was increased. Moreover, FT-IR spectroscopy was applied for the chemical structure analysis indicating that Lampang clay can be transformed into metakaolin using hydrothermal at 200°C for 8 hours followed by the calcination at 800°C and 900°C as well as through the most condition for this studied. The improvement of the surface area of metakaolin leads to high metal dispersion for catalytic activity of the catalyst.
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Effect of mixing of carbon support from sawdust and sugarcane bagasse by hydrothermal carbonization for synthesis of molybdenum disulfide (MoS2) catalyst
(2018-01-01)
Sumtong, Peerawith
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Goodwin, Vituruch
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Chollacoop, Nuwong
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Eiad-Ua, Apiluck
Molybdenum disulfide (MoS<inf>2</inf> ) catalyst on carbon support from varying ratio of sawdust and sugarcane bagasse has been successfully synthesized by hydrothermal carbonization and calcination process. Hydrothermal carbonization of lignocellulosic structure into carbon support is investigated at 200o C for 24 hr and calcination at 600o C for 2 hr. The precursor of MoS<inf>2</inf> catalyst is prepared using thiourea (CH<inf>4</inf> N<inf>2</inf> S) and ammonium molybdate tetrahydrate ((NH<inf>4</inf> )<inf>6</inf> Mo<inf>7</inf> O<inf>24</inf>. 4H<inf>2</inf> O) loaded on carbon support. The lignocellulosic structure as hemicellulose and cellulose is changed at high temperature via hydrothermal carbonization and calcination. The distribution of molybdenum disulfide on carbon support is varied based on morphology and functional group of carbon support. The morphology and functional group were analyzed using Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). It shows that carbon support at equal ratio (1:1) of sawdust and sugarcane bagasse is an optimum ratio with high distribution of molybdenum disulfide catalyst on carbon support.
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Influence of temperature and alkaline activation for synthesis zeolite a from natural kaolin
(2017-01-01)
Thungngern, Pimpreeya
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Amnaphiang, Phanwatsa
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Asawaworarit, Panuruj
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Goodwin, Vituruch
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Chollacoop, Nuwong
Zeolite A from natural kaolin have been successfully synthesized via calcination and hydrothermal. However, these techniques have one drawback since, the impurities in kaolin such as muscovite and quartz in the kaolin structure, which depend on temperature and alkaline activation. This work was separated into two steps, first step was used calcination technique, and second step was used hydrothermal technique. Reaction of temperature in the first step was studied the influence of temperature from 500°C to 800°C for 3 hours. In this step, kaolin transformed to metakaolin and remain the impurities. Next, reaction of alkaline activation in second step was studied about the influence of NaOH. The concentration of NaOH in hydrothermal was varied from 1M to 4M and mixed with metakaolin at 90°C for 72 hours. X-ray Diffraction Spectroscopy (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used for characterization. The solid products were formed to zeolite A at 1M NaOH hydrothermal with 500oC to 800oC calcination and it can be seemed good of euhedral structure at 700oC.
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Synthesis and characterization of cubic-like zinc stannate powders prepared by co-precipitation method
(2016-01-01)
Mekprasart, Wanichaya
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Tangcharoen, Thanit
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Nakhanivej, Puritat
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Pecharapa, Wisanu
Spinel-type zinc stannate (Zn<inf>2</inf>SnO<inf>4</inf>) powders were synthesized by co-precipitation method using zinc chloride and tin chloride as the precursors for Zn and Sn sources, respectively. Co-precipitation process is one of effective techniques due to non-complex system, short process time, high yield, large scale production and cost-effectiveness comparing to other methods. The influence of calcination temperature in the range of 900 °C to 1100 °C on the structure, morphologies and cation distribution were studied using various characterization techniques. A single spinel structure phase formation after-calcined powders are confirmed by X-ray diffraction (XRD) results meanwhile scanning electron microscope (SEM) showed the appearance of cubic-like shape. The aggregation of particle and strong crystallinity was distinctly increased resulting to their greater size by the effect of high calcined temperature. Moreover, the non-equilibrium site occupancy of zinc (Zn2+) and tin (Sn4+) ions was investigated through Zn K-edge and Sn L3-edge investigated by X-ray absorption (XAS) spectra via the synchrotron radiation light source. Compared with the calcined temperature sample, XANES spectra revealed that the oxidation state of Zn was +2 and Sn valence was +4 in all spinel Zn<inf>2</inf>SnO<inf>4</inf> samples which well corresponds to the theoretical values.
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Characterization and effect of calcination temperature on structural properties of spinel zinc aluminate synthesized via Co-precipitation process
(2015-06-01)
Mekprasart, Wanichaya
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Worasawat, Suchada
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Tangcharoen, Thanit
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Pecharapa, Wisanu
Zinc aluminate (ZnAl<inf>2</inf>O<inf>4</inf>) nanopowders were synthesized by co-precipitation method using zinc chloride and aluminum chloride as starting precursors. The calcination temperature which was a crucial preparation factor was varied and its influence on relevant physical properties of the product was investigated. Structural properties of synthesized nanoparticles were investigated by X-ray diffraction, X-ray absorption spectroscopy, scanning electron microscope, and Raman spectroscopy. The results suggest that that ZnAl<inf>2</inf>O<inf>4</inf> in spinel structure with high crystallinity can be obtained after calcination beyond specific temperature affirmed by XRD results. Raman result indicates the correlated chemical bonding relating to the formation of ZnAl<inf>2</inf>O<inf>4</inf> structure. Meanwhile, the Zn K-edge X-ray absorption near-edge structure (XANES) spectra of these samples with different calcination temperature obtained from the synchrotron X-ray absorption spectroscopy measurement show the existence of accurate oxidation state for zinc ion (Zn2+) in the spinel crystal structure. Moreover, it is revealed that the calcination temperature has significant effect on the local environment of the zinc absorbing atoms through the interesting change of white line appearance.
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Effect of calcination conditions on phase formation of microwave dielectric cobalt niobate (CoNb2O6) powders via a mixed oxide synthesis route
(2008-10-10)
Chaiyo, Nopsiri
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Vittayakorn, Naratip
Cobalt niobate (CoNb<inf>2</inf>O<inf>6</inf>) powders have been prepared using a mixed oxide synthesis route. The formation of the CoNb<inf>2</inf>O <inf>6</inf> phase in the calcined powders has been investigated as a function of calcination conditions by differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. The morphological evolution was determined by scanning electron microscopy (SEM). It has been found that the minor phases of unreacted Co<inf>3</inf>O<inf>4</inf> and the orthorhombic-Nb<inf>2</inf>O <inf>5</inf> and monoclinic-β-Nb<inf>2</inf>O<inf>5</inf> phase tend to form together with the columbite CoNb<inf>2</inf>O<inf>6</inf> phase, depending on calcination conditions. It is seen that optimization of calcination conditions can lead to a single-phase orthorhombic CoNb<inf>2</inf>O <inf>6</inf>. The calcination temperature and dwell time have been found to have a pronounced effect on the phase formation of the calcined cobalt niobate (CoNb<inf>2</inf>O<inf>6</inf>) powders. Optimization of calcination conditions can lead to a single-phase CoNb<inf>2</inf>O<inf>6</inf> in a columbite phase.
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Synthesis and a crystal structural study of microwave dielectric Zirconium Titanate (ZrTiO4) powders via a mixed oxide synthesis route
(2006-12-01)
Vittayakorn, Naratip
A mixed oxide synthesis route has been investigated for the synthesis of zirconium titanate, ZrTiO<inf>4</inf>. The formation of ZrTiO<inf>4</inf> phases have been investigated as a function of calcination temperature by XRD. The crystal structure, particle size distribution, morphology and phase composition of the calcined powders were determined via XRD and SEM. It has been found that with increasing calcination temperature up to 1150°C, the results showed that anatase-TiO<inf>2</inf> changed structure to rutile-TiO<inf>2</inf>. The yield of the ZrTiO<inf>4</inf> phase increased significantly up to 1350°C, when a single phase of ZrTiO<inf>4</inf> was formed, revealing that the rutile-TiO<inf>2</inf> had completely reacted with the ZrO<inf>2</inf> phase. It seemed that the pure wolframite phase of ZrTiO<inf>4</inf> powders was successfully obtained from calcinations conditions of 1350°C for 4 h with heating/cooling rates of 5 Kminute-1.

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