scholarly journals β-Cyclodextrin-Calcium Complex Intercalated Hydrotalcites as Efficient Catalyst for Transesterification of Glycerol

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1307
Author(s):  
Guanhao Liu ◽  
Jingyi Yang ◽  
Xinru Xu

β-cyclodextrin derivative intercalated MgAl-hydrotalcites (β-CD-Ca/LDH) was synthesized to convert glycerol into high value-added glycerol carbonate(GC) by transesterification of dimethyl carbonate (DMC) and glycerol in this paper. β-cyclodextrin-metal complexes and β-CD-Ca/LDH was characterized by XRD, FT-IR, SEM, XPS and nitrogen adsorption-desorption. The enrichment of organic reactants in the hydrophobic cavity of β-cyclodextrin improved the collision probability of reactants. The intercalation of β-cyclodextrin-calcium complex (β-CD-Ca) increased the pore size and basic strength of catalyst. The experiment results showed that the glycerol conversion was 93.7% and the GC yield was 91.8% catalyzed by β-CD-Ca/LDH when the molar ratio of DMC and glycerol was 3:1, the catalyst dosage was 4 wt.%, the reaction temperature was 75 °C and the reaction time was 100 min while the glycerol conversion was 49.4% and the GC yield was 48.6% catalyzed by MgAl-LDH under the same conditions.

2018 ◽  
Vol 192 ◽  
pp. 03045 ◽  
Author(s):  
Wanichaya Praikaew ◽  
Worapon Kiatkittipong ◽  
Kunlanan Kiatkittipong ◽  
Navadol Laosiripojana ◽  
Navin Viriya-empikul ◽  
...  

Waste eggshell is proposed as a highly active catalyst for glycerol carbonate production from dimethyl carbonate (DMC) and glycerol. The effect of reaction temperature, reaction time and catalyst loading on the reaction performance were investigated in order to find a suitable operating condition. CaO derived from waste eggshell exhibits catalytic activity comparable to commercial CaO. By using CaO eggshell, glycerol conversion of 96% can be achieved within 90 min of reaction time under 2.5:1 feed molar ratio of DMC to glycerol, 0.08 mole ratio of CaO to glycerol and reaction temperature of 60°C. The catalyst was examined by XRD, TGA/DSC, SEM, N2 adsorption-desorption and Hammett indicators method. Utilization of eggshell as a catalyst for glycerol carbonate production not only provides a cost-effective and value-added of waste eggshell as a green catalyst, but also decrease amount of waste and its treatment cost which is ecologically friendly.


Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4355
Author(s):  
Guanhao Liu ◽  
Jingyi Yang ◽  
Xinru Xu

Ca-Mg-Al hydrotalcites were prepared by coprecipitation from Type S95 steel slag of Shanghai Baosteel Group as supports of ionic liquid in this paper. Five basic ionic liquids [Bmim][CH3COO], [Bmim][HCOO], [Bmim]OH, [Bmim]Br and ChOH were prepared and their catalytic performance on the synthesis of glycerol carbonate by transesterification between dimethyl carbonate and glycerol was investigated. The characterization results indicated that [Bmim]OH is the best ionic liquid (IL) for the transesterification reaction of glycerol carbonate. The hydrotalcites before and after intercalation by ionic liquid were characterized by XRD, FTIR, SEM, EDS and the IL were characterized by FT-IR, 13C-NMR and basicity determination via the Hammett method. The analysis results implied that the dispersion of [Bmim]OH in hydrotalcites reduced the alkali density appropriately and facilitated the generation of glycerol carbonate. The yield of glycerol carbonate and the conversion rate of glycerol reached 95.0% and 96.1%, respectively, when the molar ratio of dimethyl carbonate and glycerol was 3:1, the catalyst dosage was 3 wt%, the reaction temperature was 75 °C and the reaction time was 120 min. The layered structure of hydrotalcites increased the stability of ionic liquid intercalated in carriers, thus the glycerol conversion and the GC yield still remained 91.9% and 90.5% in the fifth reaction cycle.


Author(s):  
T. F. Kouznetsova ◽  
A. I. Ivanets ◽  
J. D. Sauka

Titania-silica membranes on a porous quartz substrate are prepared by its direct contact with metal silicate sol at various Ti/Si ratios in the conditions of coagel sedimentation and presence of cetylpyridinium chloride. The study of textural and adsorption properties of membranes is conducted by low-temperature nitrogen adsorption-desorption, including methods of t-plots and DFT theory. It was shown that obtained membranes have mesoporous structure with the specific surface area and pore hydraulic diameter varied in intervals of 64–217 m2 /g and 4–11 nm, respectively. Developed values of surface area remain up to molar ratio of Ti/Si = 50/50.


2017 ◽  
Vol 6 (2) ◽  
pp. 143-149 ◽  
Author(s):  
Reviana Inda Dwi Suyatmo ◽  
Hary Sulistyo ◽  
Wahyudi Budi Sediawan

The growing utilization of biodiesel as a renewable fuel has generated a large surplus of glycerol as a major byproduct. The prices of glycerol continue to drop in such an oversaturated market. Therefore, new uses are being developed for glycerol to produce value-added chemicals. Among those chemicals, glycerol carbonate has many application in various fields. Glycerol carbonate is mostly used as a solvent in cosmetic and pharmacheutical industries due to its low toxicity, high boiling point, and low vapor pressure. The synthesis of glycerol carbonate from glycerol and urea using Amberlyst15 as a catalyst was being conducted in this study. The reaction was carried out using a batch reactor for 5 hours with the condition of the reaction temperature was around 120oC, mole ratios of reactant of urea:glycerol were 0.8:1, 0.9:1, 1:1, and 1.2:1 , catalyst concentrations were 2%, 2,5%, 3%, and 4%, and mixing speeds were 370 rpm, 525 rpm, and 700 rpm. It is found that the optimum conversion of glycerol was obtained at 120oC with 5 hours of reaction using an equimolar amount of glycerol and urea with catalyst load of 3%. Mixing speed did not affect glycerol conversion. Amberlyst15 as catalyst was also stable enough to be reused at least for three times.


2019 ◽  
Vol 8 (1) ◽  
pp. 128-134 ◽  
Author(s):  
Emine Kaya Ekinci ◽  
Nuray Oktar

Abstract A series of active and selective MCM-41 supported catalysts have been successfully prepared and used for bioderived glycerol esterification with acetic acid to produce fuel additives. In the synthesis of MCM-41, an acidic hydrothermal synthesis route was used, and silicotungstic acid (STA) and zirconia (ZrO2) were added to the catalyst structure by wet impregnation. X-ray diffraction, nitrogen adsorption-desorption methods, scanning electron microscopy with energy-dispersive spectroscopy, and inductively coupled plasma-mass spectrometry analysis were used for characterizations of the catalysts. Diffuse reflectance infrared Fourier transform spectroscopy analyses of pyridine-adsorbed catalysts owns Lewis and Brønsted acidity hosting in one, which promotes the esterification reaction of glycerol into glycerol esters with high selectivity. Esterification of glycerol reactions were performed at temperature intervals of 105°C–200°C, with an amount of catalyst equal to 0.5 g, and glycerol/acetic acid molar ratio of 1:6 in a stirred autoclave reactor operated batchwise. STA and ZrO2-impregnated MCM-41 catalysts showed better performance with a complete glycerol conversion and high selectivity to triacetin.


BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 142-158 ◽  
Author(s):  
Song Wang ◽  
Jianye Wang ◽  
Patrick U. Okoye ◽  
Shuang Chen ◽  
Xinshu Li ◽  
...  

Corncob was calcined within a temperature range of 300 °C to 700 °C to prepare a series of corncob residue catalysts for the transesterification of glycerol with dimethyl carbonate (DMC) to synthesize glycerol carbonate (GC). Among the catalysts, the corncob residue catalyst obtained through calcination of corncob at 500 °C (CCR-500) showed a relatively high basicity and satisfactory catalytic activity. The structural investigation results indicated that CCR-500 was composed of carbon material and some alkaline mineral salts. Using CCR-500 as the catalyst, a glycerol conversion of 98.1% and a GC yield of 94.1% were achieved when the reaction was performed at 80 °C for 90 min, with a catalyst amount of 3 wt% and glycerol to DMC molar ratio of 1:3. The comparison of CCR-500 with the reported catalysts indicated that the CCR-500 was a low-cost, high-active, and easily-accessible catalyst for the transesterification of glycerol with DMC.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Pham Dinh Du ◽  
Nguyen Trung Hieu ◽  
Tran Vinh Thien

Zeolitic imidazolate framework-8 (ZIF-8) is synthesized quickly at room temperature in methanol with the support of ultrasound. Porous ZnO is also prepared via the thermal treatment of ZIF-8. The photocatalytic activities of the obtained materials are demonstrated via methylene blue (MB) decomposition under UV radiation. The obtained materials are characterized by means of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), nitrogen adsorption/desorption isotherms, UV-Vis diffuse reflectance spectra (DR-UV-Vis), and photoluminescence spectra. The results indicate that ZIF-8 and the materials obtained from ZIF-8 by heating in the air have photocatalytic activity under UV irradiation. The ZnO sample obtained by ZIF-8 calcination at 660°C for 5 h has the highest photocatalytic activity. However, the MB degradation photocatalytic efficiency of the ZnO samples is even lower than that of the ZIF-8 samples, indicating that ZIF-8 is an effective photocatalyst in the treatment of environmental pollution.


2019 ◽  
Vol 62 (4) ◽  
Author(s):  
Venkatesh Venkatesh ◽  
Mohamed Shamshuddin Sathgatta Zaheeruddin ◽  
Pratap Srinivasa Raghavendra

Abstract. Solid base catalysts such as Ceria-Zirconia-Magnesia with different mole ratio of magnesium were prepared by impregnation method and characterized by CO2-TPD, PXRD, FT-IR and ICP-OES analysis. The catalytic activity of the catalysts was tested in the liquid phase transesterification of glycerol with dimethyl carbonate to synthesise glycerol carbonate. Optimization of reaction condition was carried out by varying the molar ratio of the reactants, temperature and time. The highest yield (97 %) of glycerol carbonate was obtained at a reactant molar ratio of 1:3 at 120 °C in 6 h. Study of reusability and reactivation of solid base catalyst was also taken up. A suitable base catalysed mechanism for the formation of glycerol carbonate is proposed.Resumen. Se prepararon catalizadores de base sólida como Ceria-Zirconia-Magnesia con diferentes proporciones molares de magnesio mediante el método de impregnación y se caracterizaron por análisis de CO2-TPD, PXRD, FT-IR e ICP-OES. La actividad catalítica de los catalizadores se probó en la transesterificación en fase líquida de glicerol con carbonato de dimetilo para sintetizar carbonato de glicerol. La optimización de las condiciones de reacción se llevó a cabo variando la relación molar de los reactivos, la temperatura y el tiempo. El mayor rendimiento (97 %) de carbonato de glicerol se obtuvo a una relación molar reactiva de 1:3 a 120 °C en 6 h. También se realizó un estudio de la reutilización y reactivación del catalizador de base sólida. Se propone un mecanismo catalítico básico adecuado para la formación de carbonato de glicerol.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4722
Author(s):  
Lukáš Žid ◽  
Vladimír Zeleňák ◽  
Miroslav Almáši ◽  
Adriana Zeleňáková ◽  
Jaroslava Szücsová ◽  
...  

In this work we describe the relationship between surface modification of hexagonally ordered mesoporous silica SBA-15 and loading/release characteristics of nonsteroidal anti-inflammatory drug (NSAID) naproxen. Mesoporous silica (MPS) was modified with 3-aminopropyl, phenyl and cyclohexyl groups by grafting method. Naproxen was adsorbed into pores of the prepared MPS from ethanol solution using a solvent evaporation method. The release of the drug was performed in buffer medium at pH 2 and physiological solution at pH 7.4. Parent MPSs as well as naproxen loaded MPSs were characterized using physicochemical techniques such as nitrogen adsorption/desorption, thermogravimetric analysis (TG), Zeta potential analysis, Fourier transform infrared spectroscopy (FT-IR), and elemental analysis. The amount of naproxen released from the MPSs into the medium was determined by high-performance liquid chromatography (HPLC). It was shown that the adsorption and desorption characteristics of naproxen are dependent on the pH of the solution and the surface functionalization of the host.


2013 ◽  
Vol 702 ◽  
pp. 56-61 ◽  
Author(s):  
Rahmatollah Rahimi ◽  
Masoumeh Mahjoub Moghaddas ◽  
Solmaz Zargari ◽  
Rahim Rahimi

Mesoporous vanadium doped titania (V-TiO2) photocatalyst was synthesized with the use of a new surfactant (Gemini) for the first time. In order to investigate the surfactant effect on the photocatalytic activity of catalysts, different surfactants containing Gemini, pluronic F127, pluronic P123, CTAB, Hexadecylamine and PEG 6000 were used in the preparation of mesoporous V-TiO2photocatalyst as a templating agent. The catalysts were characterized by FT-IR, XRD, SEM, EDX, nitrogen adsorption-desorption isotherm, and DRS. The nanosized V-TiO2 with Gemini surfactant (V-TiO2(G)) exhibited the highest visible light driven photocatalytic efficiency for degrading MO dye. The results showed that the surfactant type played an important role on the structure and photocatalytic activity of the samples.


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