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Author: search.filters.author.Chollacoop, NuwongSubject: search.filters.subject.Hydrothermal

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    Combination of natural silica and alumina sources for synthesis of MCM-22 zeolite
    (2023-08-01)
    Tanwongwan, Worapak
    ;
    Chollacoop, Nuwong
    ;
    Faungnawakij, Kajornsak
    ;
    Assabumrungrat, Suttichai
    ;
    Nakhanivej, Puritut
    Zeolite has become a promising material that can potentially play a pivotal role in resolving environmental crises. Among zeolite families, MCM-22 zeolite shows outstanding intrinsic properties associated with the topology and porous structure, offering ion-exchange advantages for catalytic activity processes. The synthesis of MCM-22 zeolite becomes challenging when concerning the cost and catalytic performance. To overcome this bottleneck, we demonstrate a sustainable route of a hydrothermal process using natural resources as starting materials. Rice husk from agricultural waste was used as a silica source while natural clays (kaolin and bentonite) were applied as alumina sources. The products from natural sources were compared with the use of commercial starting materials, e.g., NaAlO<inf>2</inf> (for alumina) and Na<inf>2</inf>SiO<inf>3</inf> and TEOS (for silica), in points of crystal, compositional, and morphological views. We showed that the high purity of MCM-22 zeolite can be obtained from rice husk silica (RHS) and aluminosilicate gel (ASG) extracted from kaolin, while the use of ASG extracted from bentonite tended to be unsuitable to generate the zeolite formation. We also studied the effects of reaction time and the ratio of RHS/ASG on the crystallinity and surface area of MCM-22. The architecture and acidity of an optimal product were explored by Nuclear magnetic resonance spectroscopy and Temperature-programmed desorption of ammonia, demonstrating the success of achieving well acidity.
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    Zeolite P from kaolin via hydrothermal method
    (2018-09-05)
    Eiad-Ua, Apiluck
    ;
    Amnaphiang, Phanwasa
    ;
    Asawaworarit, Panuruj
    ;
    Houngkamhang, Nongluck
    ;
    Chollacoop, Nuwong
    Zeolite P has been successfully synthesized from natural kaolin via two step hydrothermal process. The natural kaolin from Lampang, Thailand was studied for this research. In first hydrothermal, kaolin was mixed with sodium hydroxide solution at 200 <sup>o</sup>C for different reaction times from 3 - 5 hours, respectively.Sodium hydroxide and hydrochloric acid were added into the mixture to adjust their pH before they were formed into gel. Second hydrothermal process, the gel was kept of 90 <sup>o</sup>C for 3 days to obtain zeolite P. Synthesized zeolite P was characterized by X-ray diffraction (XRD) for identification the type and crystallization. Besides, the morphology was characterized by scanning electron microscopy)SEM.(The functional group was characterized by Fourier-transform infrared spectroscopy (FTIR). From this study, it was found that the increasing of reaction time in first hydrothermal activation and hydrochloric acid concentration lead to the high quality of zeolite P.
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    Synthesis of molybdenum disulfide support on carbon for upgrading bio-oil from jatropha residue
    (2017-01-01)
    Nakapan, Kantapat
    ;
    Chollacoop, Nuwong
    ;
    Viriya-Empikul, Nawin
    ;
    Eiad-Ua, Apiluck
    Bio-oil or pyrolysis oil can be obtained from fast pyrolysis biomass has several unusual characteristic such as high acid and high oxygen content which cause bio oil not proper to use as a fuel. In this research MoS<inf>2</inf> support on carbon material was prepared for the upgrading bio oil via impregnation method on carbon support from biomass. Hydrothermal process which aims to convert biomass into value products. This process usually performed in water and produces the product, namely hydrochar. In this research, bagasse were executed by hydrothermal at 160 °C, 180 °C and 200 °C for 2, 4, 8 and 24 hours each to enhance the porosity of their products. High porosity is well-known desirably for enhancing efficiency of supporting agents since it can load more catalyst quantity. After finishing hydrothermal process, the reactor which carried bagasse was quenching in order to inhibit the reaction inside. Then, the hydrochar was impregnated by MoS<inf>2</inf> precursor and carbonized at 450 °C for 2 hours under nitrogen atmosphere to stabilize the metal phase and turned hydrochar into carbon support. MoS<inf>2</inf>/carbon was characterized by scanning electron microscopy, EDX, FTIR and pyrolyzer gas chromatography/mass spectroscopy.
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    Influence of temperature and alkaline activation for synthesis zeolite a from natural kaolin
    (2017-01-01)
    Thungngern, Pimpreeya
    ;
    Amnaphiang, Phanwatsa
    ;
    Asawaworarit, Panuruj
    ;
    Goodwin, Vituruch
    ;
    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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    Effect of alkaline activation on low grade natural kaolin for synthesis of zeolite A
    (2016-01-01)
    Asawaworarit, Panuruj
    ;
    Chollacoop, Nuwong
    ;
    Viriya-Empikul, Nawin
    ;
    Eiad-Ua, Apiluck
    The conventional technique to synthesizes zeolite A from kaolin is calcination. However, this technique has one drawback since, the impurities in kaolin, such as muscovite and quartz, remain. Therefore, the hydrothermal process without calcination is used to synthesize high purity zeolite A. Hydrothermal synthesis without calcination can be separated into two steps, namely first and second hydrothermal steps. Alkaline activation reaction in the first hydrothermal step was used to study the effect of NaOH concentration ranging from 4M, 6M, 8M, 10M to 12M at 200°C for 3 hours. In this step, sodium aluminosilicate (cancrinite and nepheline hydrate) was produced and then dissolved in HCl. After filtration, the impurity was removed, and adjusted for neutral pH of 7 to form amorphous aluminosilicate gel. For the second hydrothermal step, amorphous gel was mixed with NaOH (1-4M) to form zeolite A at 90°C for 3 days. The x-ray diffraction (XRD) and Scanning Electron Microscope (SEM) were used for characterization.