scholarly journals Glycerol Esterification for Triacetin Production using Fe3O4@SiO2@PO43- as Heterogeneous Magnetic Catalyst

2021 ◽  
Author(s):  
Amjad Ali ◽  
Km Abida ◽  
Ritika Jindal
Keyword(s):  
Acetic Acid ◽  
Solid Catalyst ◽  
X Ray Diffraction ◽  
Consecutive Reaction ◽  
Glycerol Conversion ◽  
Magnetic Catalyst ◽  
Transmission Electron ◽  
Plausible Mechanism ◽  
Reaction Cycles ◽  
Glycerol Esterification

Abstract To facilitate the magnetic separation, phosphate group is embedded onto silica-coated Fe3O4 magnetic nanoparticles to prepare Fe3O4@SiO2@PO43− solid catalyst for the glycerol esterification with acetic acid. The catalyst was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating magnetic spectroscopy (VSM) and Fourier Transform Infrared (FTIR) spectroscopy. The Fe3O4@SiO2@PO43− magnetic catalyst during the glycerol esterification with acetic acid was found to demonstrate excellent glycerol conversion levels (97 %) while retaining 92 % triacetin selectivity. The plausible mechanism of glycerol esterification suggests the initiation of the reaction by the protonation of the acetic acid. The catalyst was recovered from the reaction mixture under the influence of external magnetic field and reused during 4 consecutive reaction cycles.

Esterification of glycerol with acetic acid using a sulfonated polyphenylene sulfide non-woven fabric as a catalyst

2020 ◽  
Vol 18 (12) ◽  
Author(s):  
Xueyang Li ◽  
Jiao Zhang ◽  
Yunfei Song ◽  
Yanhong Ji ◽  
Mohammad Younas ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Polyphenylene Sulfide ◽  
Woven Fabric ◽  
Molar Ratio ◽  
Solid Catalyst ◽  
Glycerol Conversion ◽  
Good Catalytic Activity ◽  
Reaction Cycles

AbstractIn this work, the esterification of glycerol with acetic acid (HOAc) was investigated under sulfonated polyphenylene sulfide non-woven fabric (SPSF) as a solid catalyst. The effects of the amount of catalyst, reaction temperature, molar ratio of glycerol to HOAc and the reaction time on the esterification were studied in detail. It was found that SPSF has good catalytic activity and stability. Under the reaction conditions of the molar ratio of glycerol/HOAc of 1:6 (glycerol 0.1 mol), the reaction temperature of 110 °C, the amount of catalyst of 3 g, and the reaction time of 2 h, the glycerol conversion and the selectivity to diacetin (DAG) reached upto 96 and 56.1%, respectively. Reusability test of SPSF showed that no significant declination in the glycerol conversion and the selectivity was observed after five reaction cycles. The experimental results proved the esterification of glycerol with HOAc by SPSF a promising and green process.

scholarly journals PEMBUATAN BIOADITIF TRIACETIN DENGAN KATALIS PADAT SILICA ALUMINA

2017 ◽  
Vol 5 (2) ◽  
pp. 101-109 ◽  
Author(s):  
Agus Aktawan ◽  
Zahrul Mufrodi
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Acetic Acid ◽  
Reaction Time ◽  
Biodiesel Production ◽  
Gas Chromatography Mass Spectrometry ◽  
Solid Catalyst ◽  
Heating Unit ◽  
Glycerol Conversion ◽  
Silica Alumina

Triasetin is a bioaditif to increase the octane number of the gasoline. Triasetin was generated from the reaction between giserol and acetic acid. Glycerol is a byproduct of biodiesel production. Triasetin production can reduce glycerol which is actually a waste by converting it into bioaditif having higher value. The reaction can be accelerated by addition of catalysts either solid or liquid catalyst. The reaction in this study used a solid catalyst types Silica Alumina. The reaction takes place in the three-neck flask reactor which is equipped with heating unit, mixers, and tools to take samples at regular intervals. Variables used in this research is the variety of reaction time and the reaction temperature (70, 80, 90, 100, and 1100C). The concentration of triasetin obtained will be known through the analysis of Gas Chromatography - Mass Spectrometry (GC-MS). The results of the analysis of GC or GC-MS treated or counted so getting glycerol conversion and selectivity of triasetin. The highest glycerol conversion 8,45% occurs at a temperature of 700C the reaction time of 90 minutes with triasetin selectivity 100%.

Low Melting Metal Catalysed Growth of Tin Disulfide Nanotubes

2009 ◽  
Vol 1178 ◽  
Author(s):  
Aswani Yella ◽  
Enrico Mugnaioli ◽  
Martin Panthoefer ◽  
Ute Kolb ◽  
Wolfgang Tremel
Keyword(s):  
Horizontal Tube ◽  
Single Step ◽  
X Ray Diffraction ◽  
Product Analysis ◽  
Pure Material ◽  
Tem Analysis ◽  
X Ray ◽  
Tin Disulfide ◽  
Transmission Electron ◽  
Plausible Mechanism

AbstractWe report here the synthesis of tin disulfide nanotubes by a vapour liquid solid growth using bismuth, a low melting metal, as a catalyst. The reaction was carried out in a single step process by heating SnS2 and bismuth in a horizontal tube furnace at 800oC. TEM analysis allowed proposing a plausible mechanism for the formation of SnS2 nanotubes. Pure material could be obtained by optimizing the reaction based on a product analysis using powder X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) combined with energy dispersive X-ray spectroscopy (EDX).

scholarly journals Adsorption characteristics of 2,4-dichorophenoxy acetic acid onto surfactant modified titania nanoparticles

2021 ◽  
Vol 10 (4) ◽  
pp. xx-xx
Author(s):  
Dung Le Thi ◽  
Loan Nguyen Quynh ◽  
Thang Nguyen Duc ◽  
Son Le Thanh ◽  
Duc Pham Tien
Keyword(s):  
Acetic Acid ◽  
Surface Modification ◽  
Cetyltrimethylammonium Bromide ◽  
Sol Gel ◽  
Titania Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Mechanisms ◽  
Transmission Electron ◽  
Effective Conditions

The present study investigated adsorption of 2,4-dichorophenoxy acetic acid(2,4-D) on titania (TiO2) nanoparticles with surface modification by cationic surfactant, cetyltrimethylammonium bromide (CTAB). Titania nanoparticles which were successfully synthesized by sol-gel method, were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Surface modification of TiO2 with CTAB enhanced the removal of 2,4-D significantly. Some effective conditions affect to the removal of 2,4-D using CTAB modified TiO2 such as pH and adsorbent dosage were systematically studied and found to be 5 and 10 mg/mL, respectively. Adsorption mechanisms of 2,4-D onto CTAB modified TiO2 was suggested based on the change in surface charge after adsorption. 

scholarly journals The effect of the synthesis conditions on structure and photocatalytic activity of Nb2O5 nanostructures

2018 ◽  
Vol 12 (3) ◽  
pp. 218-229 ◽  
Author(s):  
Caterine Gómez ◽  
Jorge Rodríguez-Páez
Keyword(s):  
Acetic Acid ◽  
Niobium Pentoxide ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Photo Degradation ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Heat Treated ◽  
Solid Precipitate ◽  
Controlled Precipitation

In this work, niobium pentoxide (Nb2O5) nanoparticles of varying sizes and morphology were synthesized using the controlled precipitation method. Ammonium niobate oxylate hydrate (NH4)H2[NbO(C2O4)3] ? 3H2O was used as a niobium precursor and distilled water or acetic acid was used as solvent. The obtained solids were characterized using Fourier transform infrared and Raman spectroscopies, X-ray diffraction and transmission electron microscopy. The as-synthesized solid precipitate was amorphous, but after heat treatment between 500?C and 600?C, the T-Nb2O5 phase was obtained. The size of the primary particles of the niobium pentoxide was nanometric (<100 nm), with agglomerate size of >500 nm, when water was used as a solvent for synthesis. Considering the nature of the process, a possible reaction mechanism of the precursor with the water and NH4OH was proposed, which explains the formation of the solid within an aqueous solution. Considering one potential use of Nb2O5 synthesized in this work, the photo-degradation action of the particles on the organic molecule methylene blue was tested. The sample synthesized in acetic acid at pH ~9.0 and heat treated at 600?C showed the highest photo-degradation capacity, with a degradation of ~60% of the dye for 60 minutes.

A Kinetic Study of Glycerol Esterification with Acetic Acid Over a Commercial Amberlyst-35 Ion Exchange Resin

2019 ◽  
Vol 70 (7) ◽  
pp. 2325-2329
Author(s):  
Ionut Banu ◽  
Grigore Bozga ◽  
Gheorghe Bumbac ◽  
Alin Vintila ◽  
Sanda Velea ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Molar Ratio ◽  
Glycerol Conversion ◽  
Molar Ratios ◽  
Simple Kinetic Model ◽  
Petroleum Derivatives ◽  
Glycerol Esterification ◽  
Autoclave Reactor

The increased quantities of glycerol available on the market initiated research efforts oriented to new valorization technologies, particularly by its conversion into medium tonnage chemicals, replacing petroleum derivatives. In this work it was investigated the valorization of glycerol by its transformation in glycerol acetates, by direct esterification with acetic acid, over a commercial Amberlyst-35 resin. Experiments were carried out batch-wise, in an autoclave reactor under controlled working conditions, at temperatures between 95 and 112 oC and initial acetic acid to glycerol molar ratios between 4 and 9. The experimental data evidenced that the glycerol conversion to monoacetate is faster than the next esterification steps. A relatively simple kinetic model was proposed and its parameters were evaluated from the experimental measurements. It proved reasonable predicting capacity for products distribution dependencies on the reactants molar ratio and reaction temperature.

Morphological evolution of calcium apatites from nanorods to hollow spheres mediated by acetic acid

2009 ◽  
Vol 24 (8) ◽  
pp. 2499-2502 ◽  
Author(s):  
Junfeng Hui ◽  
Daidi Fan
Keyword(s):  
Acetic Acid ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Morphological Evolution ◽  
Hollow Spheres ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Acid Aqueous Solution ◽  
The Stability

Hydroxyapatite (HAp) and brushite (DCPD) are two important compounds of the calcium apatite family with excellent bioactivity and osteoconductive properties in vivo. This work aimed to investigate the stability of HAp nanorods synthesized by the hydrothermal method in acetic acid aqueous solution. The results illuminated that HAp nanorods were converted into hollow nanospheres, and it was found that the concentration and amount of the acetic acid and the reaction time significantly affected the degree of the morphological evolution. Transmission electron microscope, high-resolution transmission electron microscope, and x-ray diffraction were performed for characterizing the samples.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

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