A recyclable cucurbit[6]uril-supported silicotungstic acid catalyst used in the esterification reaction

2021 ◽  
Vol 523 ◽  
pp. 120418
Author(s):  
Wen Xia ◽  
Yu-Mei Nie ◽  
Na Lei ◽  
Zhu Tao ◽  
Qiang-Jiang Zhu ◽  
...  
Keyword(s):  
Acid Catalyst ◽  
Esterification Reaction ◽  
Silicotungstic Acid

scholarly journals Synthesis, Characterization and Catalytic Performance ofH3SiW12O40/SiO2Prepared by Sol-Gel Technique

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
W. N. R. W. Isahak ◽  
M. Ismail ◽  
N. M. Nordin ◽  
J. M. Jahim ◽  
M. A. Yarmo
Keyword(s):  
Heteropoly Acid ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Environmentally Benign ◽  
Esterification Reaction ◽  
Silicotungstic Acid ◽  
Gel Technique

The purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB) and STA-silica sol-gel (STA-SG) compared with sulfuric acid. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W, and Si-O-Si bonding in STA-SG compared to that in STAB. The main spectra of O1s (90.74%, 531.5 eV) followed by other O1s peak (9.26%, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. The STA-SG catalyst was found to be the more environmentally benign solid acid catalyst for the esterification reaction between oleic acid and glycerol due to its lower toxicity supported by silica via sol-gel technique. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4and the STAB gave high conversion of 100% and 98% but at a lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94% but with a significantly higher GME selectivity of 95%, rendering it the more efficient solid acid catalyst.

Synthesis and Characterization of Silicotungstic Acid Nanoparticles via Sol Gel Technique as a Catalyst in Esterification Reaction

2011 ◽  
Vol 364 ◽  
pp. 266-271 ◽  
Author(s):  
Wan Nor Roslam Wan Isahak ◽  
Ismail Manal ◽  
Norasikin Mohd Nordin ◽  
Noraini Hamzah ◽  
Khadijeh Beigom Ghoreishi ◽  
...  
Keyword(s):  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Esterification Reaction ◽  
Homogeneous Catalyst ◽  
Silicotungstic Acid ◽  
Gel Technique ◽  
Glycerol Monooleate

Glycerol monooleate (GMO) as an esterification product of oleic acid and glycerol is highly potential as an anti-friction substance in the engine lubricant. The purpose of this work is to study the synthesis, characterization and catalytic performance of solid heteropoly acid catalysts, namely silicotungstic acid bulk (STAB) and STA-silica sol gel (STA-SG). The activity and selectivity of STAB and STA-SG in the esterification reaction have been investigated and compared to the homogeneous catalyst i.e. sulphuric acid (H2SO4). The synthesized catalysts were characterized by BET, XRD, TEM, XPS and TPD-NH3. BET analyses shown that the STA-SG catalyst is very high in surface area compared to STAB of 460.11 m2/g and 0.98 m2/g, respectively. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W and Si-O-Si bonding in STA-SG compared to that in STAB. The main species of O1s (90.74 %, 531.5 eV) followed by other O1s peak (9.26 %, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4 and the STAB gave high conversion of 100% and 98%, while lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94%, while significantly higher GME selectivity of 95% rendering it the more efficient solid acid catalyst.

scholarly journals Synthesis of Nano-Sized Protonic Acid Catalyst and Initial Kinetic Study of Esterification Reaction of Methanol with Acetic Acid

2014 ◽  
Vol 26 (16) ◽  
pp. 4988-4994
Author(s):  
Jianjun Zhu ◽  
Qiuqing Cui ◽  
Jiangping Peng ◽  
Li Li Zhang ◽  
Zhongqing Jiang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Kinetic Study ◽  
Acid Catalyst ◽  
Esterification Reaction ◽  
Protonic Acid

scholarly journals Immobilizing Ni (II)-Exchanged Heteropolyacids on Silica as Catalysts for Acid-Catalyzed Esterification Reactions

2019 ◽  
Vol 65 (1) ◽  
pp. 21-27
Author(s):  
Qiuyun Zhang ◽  
Dandan Lei ◽  
Qianqian Luo ◽  
Taoli Deng ◽  
Jingsong Cheng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Oleic Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Kinetic Studies ◽  
Esterification Reaction ◽  
High Oleic ◽  
Ft Ir ◽  
Structural Surface ◽  
Esterification Reactions

Biodiesel was synthesized from oleic acid using Ni (II)-exchanged heteropolyacids immobilized on silica (Ni0.5H3SiW / SiO2 ) as a solid acid catalyst. Based on detailed analyses of FT-IR, XRD, TG and SEM, the structural, surface and thermal stability of Ni0.5H3SiW / SiO2 were investigated. Obtained results demonstrated that the Keggin structure was well in the immobilization process and possess a high thermal stability. Various esterification reaction conditions and reusability of catalyst were studied. High oleic acid conversion of 81.4 % was observed at a 1:22 mole ratio (oleic acid: methanol), 3 wt. % catalyst at 70 °C for 4 h. The Ni0.5H3SiW / SiO2 catalyst was reused for several times and presented relatively stable. More interestingly, the kinetic studies revealed the esterification process was compatible with the first order model, and a lower activation energy was obtained in this catalytic system.

scholarly journals Titanate nanotubes-bonded organosulfonic acid as solid acid catalyst for synthesis of butyl levulinate

RSC Advances ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 3657-3662 ◽  
Author(s):  
Shuolin Zhou ◽  
Dabo Jiang ◽  
Xianxiang Liu ◽  
Yiping Chen ◽  
Dulin Yin
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Titanate Nanotubes ◽  
Esterification Reaction ◽  
Hybrid Catalyst

TiO2 nanotubes-bonded organosulfonic acid as a hybrid catalyst exhibited better activity and good reusability for esterification reaction.

scholarly journals Optimization of Biodiesel Production from Waste Cooking Oil Using S–TiO2/SBA-15 Heterogeneous Acid Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 67 ◽  
Author(s):  
Muhammad Hossain ◽  
Md Siddik Bhuyan ◽  
Abul Md Ashraful Alam ◽  
Yong Seo
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Waste Cooking Oil ◽  
Biodiesel Production ◽  
Catalyst Loading ◽  
Esterification Reaction ◽  
Impregnation Method ◽  
Cooking Oil ◽  
Heterogeneous Acid Catalyst

The aim of this research was to synthesize, characterize, and apply a heterogeneous acid catalyst to optimum biodiesel production from hydrolyzed waste cooking oil via an esterification reaction, to meet society’s future demands. The solid acid catalyst S–TiO2/SBA-15 was synthesized by a direct wet impregnation method. The prepared catalyst was evaluated using analytical techniques, X-ray diffraction (XRD), Scanning electron microscopy (SEM) and the Brunauer–Emmett–Teller (BET) method. The statistical analysis of variance (ANOVA) was studied to validate the experimental results. The catalytic effect on biodiesel production was examined by varying the parameters as follows: temperatures of 160 to 220 °C, 20–35 min reaction time, methanol-to-oil mole ratio between 5:1 and 20:1, and catalyst loading of 0.5%–1.25%. The maximum biodiesel yield was 94.96 ± 0.12% obtained under the optimum reaction conditions of 200 °C, 30 min, and 1:15 oil to methanol molar ratio with 1.0% catalyst loading. The catalyst was reused successfully three times with 90% efficiency without regeneration. The fuel properties of the produced biodiesel were found to be within the limits set by the specifications of the biodiesel standard. This solid acid catalytic method can replace the conventional homogeneous catalyzed transesterification of waste cooking oil for biodiesel production.

Sulfonated magnetic nanobiochar as heterogeneous acid catalyst for esterification reaction

2020 ◽  
Vol 8 (4) ◽  
pp. 103912 ◽  
Author(s):  
S.N. Aisyiyah Jenie ◽  
Anis Kristiani ◽  
Sudiyarmanto ◽  
Deni S. Khaerudini ◽  
Kaoru Takeishi
Keyword(s):  
Acid Catalyst ◽  
Esterification Reaction ◽  
Heterogeneous Acid Catalyst

scholarly journals Study of Soybean Oil Hydrolysis Catalyzed by Thermomyces lanuginosus Lipase and Its Application to Biodiesel Production via Hydroesterification

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Elisa d'Avila Cavalcanti-Oliveira ◽  
Priscila Rufino da Silva ◽  
Alessandra Peçanha Ramos ◽  
Donato Alexandre Gomes Aranda ◽  
Denise Maria Guimarães Freire
Keyword(s):  
Soybean Oil ◽  
Methyl Esters ◽  
Reaction Medium ◽  
Acid Catalyst ◽  
Biodiesel Production ◽  
Thermomyces Lanuginosus ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Thermomyces Lanuginosus Lipase ◽  
Niobic Acid

The process of biodiesel production by the hydroesterification route that is proposed here involves a first step consisting of triacylglyceride hydrolysis catalyzed by lipase from Thermomyces lanuginosus (TL 100L) to generate free fatty acids (FFAs). This step is followed by esterification of the FFAs with alcohol, catalyzed by niobic acid in pellets or without a catalyst. The best result for the enzyme-catalyzed hydrolysis was obtained under reaction conditions of 50% (v/v) soybean oil and 2.3% (v/v) lipase (25 U/mL of reaction medium) in distilled water and at 60∘C; an 89% conversion rate to FFAs was obtained after 48 hours of reaction. For the esterification reaction, the best result was with an FFA/methanol molar ratio of 1:3, niobic acid catalyst at a concentration of 20% (w/w FFA), and 200∘C, which yielded 92% conversion of FFAs to soy methyl esters after 1 hour of reaction. This study is exceptional because both the hydrolysis and the esterification use a simple reaction medium with high substrate concentrations.

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