scholarly journals Influence of the Metal Incorporation into Hydroxyapatites on the Deactivation Behavior of the Solids in the Esterification of Glycerol

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Gabriela Mota ◽  
José Vitor C. do Carmo ◽  
Camila B. Paz ◽  
Gilberto D. Saraiva ◽  
Adriana Campos ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Lattice Structure ◽  
Reaction Times ◽  
Active Species ◽  
Metal Species ◽  
Molar Ratio ◽  
Glycerol Conversion ◽  
Metal Contents ◽  
High Metal ◽  
Metal Incorporation

The effects of the metal incorporation into hydroxyapatites on the deactivation behavior of the solids were examined in the esterification of glycerol (EG) reaction. The introduction of Cu, Co, or Ni ions by ion exchange in calcium-deficient hydroxyapatites resulted in active catalysts for the EG reaction. The metal contents were varied from 2.0 to 17.0%, providing better performances at rather high metal contents. Part of metal species existed in the hydroxyapatite lattice structure and also as isolated Cu2+, Ni2+, and Co2+ entities on the surface, as shown by XPS and EPR. The effects of the reaction temperature, reaction time, and glycerol to acetic acid molar ratios were deeply investigated. The spent solids used in this study were characterized by XRD, FTIR, SEM-EDS, chemical analyses, EPR, and XPS. The Cu2+–OH acid pairs could promote a superior catalytic performance of Cu-containing hydroxyapatites due to the resistance of these solids against leaching of the active species, which is even better than those of Co and Ni-containing counterparts with high metal contents. Cu into hydroxyapatite had a good reusability and long-term utilization for five consecutive cycles of 24 h under a glycerol to acetic acid molar ratio of 0.25 at 80 °C, and longer reaction times provide triacetin formation. This was due to the fact that Cu was stabilized by interacting with Ca, PO4, and OH sites into the hydroxyapatite lattice, being highly active for the EG reaction. The results also revealed that isolated Cu2+ sites played an important role in enhancing the glycerol conversion, intrinsically due to the Cu-containing hydroxyapatites ability to avoid strong adsorption of glycerol oligomers on the catalytic sites.

scholarly journals Production of value-added chemicals from esterification of waste glycerol over MCM-41 supported catalysts

2019 ◽  
Vol 8 (1) ◽  
pp. 128-134 ◽  
Author(s):  
Emine Kaya Ekinci ◽  
Nuray Oktar
Keyword(s):  
Acetic Acid ◽  
High Selectivity ◽  
Supported Catalysts ◽  
Value Added ◽  
Mass Spectrometry Analysis ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Glycerol Conversion ◽  
Spectrometry Analysis ◽  
Mcm 41

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.

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 Synthesis of Triacetin Catalyzed by Activated Natural Zeolite Under Microwave Irradiation

2019 ◽  
Vol 8 (1) ◽  
pp. 01-07
Author(s):  
Dzikri Hamzah ◽  
Taufik Rinaldi ◽  
Marwan Marwan ◽  
Wahyu Rinaldi
Keyword(s):  
Acetic Acid ◽  
Quantitative Analysis ◽  
Microwave Irradiation ◽  
Natural Zeolite ◽  
Ester Group ◽  
Microwave Oven ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Glycerol Conversion ◽  
Microwave Transmission

Esterification of glycerol with acetic acid under microwave irradiation in the presence of activated natural zeolite was investigated. Natural zeolite was collected from Ujung Pancu (Aceh Besar) and chemically activated with hydrochloric acid. The reaction was carried out in a stirred glass flask reactor placed inside microwave oven. Experimental variables include microwave transmission time, molar ratio of glycerol to acetic acid, and catalyst loading. XRD profile of activated zeolite showed an increase of Si/Al ratio to 6.042 and the crystallinity decreased slightly by 12.23%, mainly due to dealumination during chemical treatment. Qualitative analysis by FTIR shows that the reaction product obtained by microwave heating contains ester group (triacetin) at wavelength 1706.669 cm-1, while the quantitative analysis by acidi-alkalimetry titration indicates the highest glycerol conversion of 93.033% at the reaction condition of the molar ratio of 1:9, catalyst loading of 3%, and microwave transmission of 10 minutes. The present work suggests that microwave can be utilized as efficient heating technique in esterification of glycerol to triacetin.

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.

scholarly journals Enzymatic Synthesis of Isopropyl Acetate by Immobilized   Bacillus cereus Lipase in Organic Medium

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Madan Lal Verma ◽  
Wamik Azmi ◽  
Shamsher Singh Kanwar
Keyword(s):  
Acetic Acid ◽  
Bacillus Cereus ◽  
Water Activity ◽  
Molecular Sieves ◽  
Immobilized Lipase ◽  
Molar Ratio ◽  
Ester Synthesis ◽  
Initial Water ◽  
Isopropyl Acetate ◽  
Mg Addition

Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM), concentration of biocatalyst (25–125 mg/mL), reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55°C in n-heptane under continuous shaking (160 rpm) using bound lipase (25 mg). Addition of molecular sieves (3 Å  × 1.5 mm) resulted in a marked increase in ester synthesis (73.0 mM). Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse.

Study on the Synthesis of Isoamyl Acetate Catalyzed by Strong Acidic Cation Exchange Resin

2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Cation Exchanger ◽  
Cation Exchange Resin ◽  
Isoamyl Acetate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Conditions ◽  
Optimum Reaction

Isoamyl acetate was synthesized from isoamylol and glacial acetic acid with strong acidic cation exchanger as catalyst. The effects of reaction conditions such as acid-alcohol ratio, reaction time, catalyst dosage to esterification reaction have been investigated and the optimum reaction conditions can be concluded as: the molar ratio of acetic acid to isoamylol 0.8:1, reaction time 2h, 25 % of catalyst (quality of acetic acid as benchmark). The conversion rate can reach up to 75.46%. The catalytic ability didn’t reduce significantly after reusing 10 times and the results showed that the catalyst exhibited preferably catalytic activity and reusability.

Microwave Irradiated Acetylation of p-Anisidine: A Step towards Green Chemistry

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Mousumi Chakraborty ◽  
Vaishali Umrigar ◽  
Parimal A. Parikh
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Green Chemistry ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Organic Solvent ◽  
Reaction Times ◽  
Microwave Energy ◽  
Operating Parameters ◽  
Feed Composition

The present study aims at assessing the effect of microwave irradiation against thermal heat on the production of N-acetyl-p-anisidine by acetylation of p-anisidine. The acetylation of p-anisidine under microwave irradiation produces N-acetyl-p-anisidine in shorter reaction times, which offers a benefit to the laboratories as well as industries. It also eliminates the use of excess solvent. Effects of operating parameters such as reaction time, feed composition, and microwave energy and reaction temperature on selectivity to the desired product have been investigated. The results indicate as high as a 98% conversion of N-acetyl-p-anisidine can be achieved within 12-15 minutes using acetic acid. The use of acetic acid as an acetylating agent against conventionally used acetic anhydride eliminates the handling of explosive acetic anhydride and also the energy intensive distillation step for separation of acetic acid. Organic solvent like acetic anhydride are not only hazardous to the environment, they are also expensive and flammable.

Few-Layered MoS2 Nanoparticles Loaded TiO2 Nanosheets with Exposed {001} Facets for Enhanced Photocatalytic Activity

NANO ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. 1850129 ◽  
Author(s):  
Chujun Chen ◽  
Xia Xin ◽  
Jinniu Zhang ◽  
Gang Li ◽  
Yafeng Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Charge Carrier ◽  
Visible Light ◽  
Recombination Rate ◽  
Active Species ◽  
Molar Ratio ◽  
Carrier Recombination ◽  
Tio2 Nanosheets ◽  
Photocatalytic Activities ◽  
Charge Carrier Recombination

To improve the high charge carrier recombination rate and low visible light absorption of {001} facets exposed TiO2 [TiO2(001)] nanosheets, few-layered MoS2 nanoparticles were loaded on the surfaces of TiO2(001) nanosheets by a simple photodeposition method. The photocatalytic activities towards Rhodamine B (RhB) were investigated. The results showed that the MoS2–TiO2(001) nanocomposites exhibited much enhanced photocatalytic activities compared with the pure TiO2(001) nanosheets. At an optimal Mo/Ti molar ratio of 25%, the MoS2–TiO2(001) nanocomposites displayed the highest photocatalytic activity, which took only 30[Formula: see text]min to degrade 50[Formula: see text]mL of RhB (50[Formula: see text]mg/L). The active species in the degradation reaction were determined to be h[Formula: see text] and [Formula: see text]OH according to the free radical trapping experiments. The reduced charge carrier recombination rate, enhanced visible light utilization and increased surface areas contributed to the enhanced photocatalytic performances of the 25% MoS2–TiO2(001) nanocomposites.

scholarly journals Characterization of Ag-promoted Ni/SiO2 Catalysts for Syngas Production via Carbon Dioxide (CO2) Dry Reforming of Glycerol

2016 ◽  
Vol 11 (2) ◽  
pp. 220 ◽  
Author(s):  
Norazimah Harun ◽  
Jolius Gimbun ◽  
Mohammad Tazli Azizan ◽  
Sumaiya Zainal Abidin
Keyword(s):  
Carbon Dioxide ◽  
Tubular Reactor ◽  
Dry Reforming ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Glycerol Conversion ◽  
Syngas Production

<p>The carbon dioxide (CO<sub>2</sub>) dry reforming of glycerol for syngas production is one of the promising ways to benefit the oversupply crisis of glycerol worldwide. It is an attractive process as it converts carbon dioxide, a greenhouse gas into a synthesis gas and simultaneously removed from the carbon biosphere cycle. In this study, the glycerol dry reforming was carried out using Silver (Ag) promoted Nickel (Ni) based catalysts supported on silicon oxide (SiO<sub>2</sub>) i.e. Ag-Ni/SiO<sub>2</sub>. The catalysts were prepared through wet impregnation method and characterized by using Brunauer-Emmett-Teller (BET) surface area, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Thermo Gravimetric (TGA) analysis. The experiment was conducted in a tubular reactor which condition fixed at 973 K and CO<sub>2</sub>:glycerol molar ratio of 1, under atmospheric pressure. It was found that the main gaseous products are H₂, CO and CH<sub>4</sub> with H₂:CO molar ratio &lt; 1.0. From the reaction study, Ag(5)-Ni/SiO<sub>2</sub> results in highest glycerol conversion and hydrogen yield, accounted for 32.6% and 27.4%, respectively. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 22<sup>nd</sup> January 2016; Revised: 22<sup>nd</sup> February 2016; Accepted: 23<sup>rd</sup> February 2016</em></p><strong>How to Cite</strong>: Harun, N., Gimbun, J., Azizan, M.T., Abidin S.Z. (2016). Characterization of Ag-promoted Ni/SiO<sub>2</sub> Catalysts for Syngas Production via Carbon Dioxide (CO<sub>2</sub>) Dry Reforming of Glycerol. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (2): 220-229 (doi:10.9767/bcrec.11.2.553.220-229)<p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.11.2.553.220-229</p>

scholarly journals Studies on biodiesel produced from Jatropha oil in Cambodia by a non-catalytic using C2H5OH

2014 ◽  
Vol 17 (2) ◽  
pp. 102-108
Author(s):  
Phuoc Van Nguyen ◽  
Chhoun Vi Thun ◽  
Quan Thanh Pham
Keyword(s):  
Catalyst Deactivation ◽  
Reaction Times ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Biodiesel Fuel ◽  
Jatropha Oil ◽  
Fuel Blend ◽  
International Standard ◽  
Astm D6751

Different technologies are currently available for biodiesel production from various kinds of lipid containing feedstock. Among them, the alkaline-catalyzed methods are the most widely studied. However, here are several disadvantages related to biodiesel production using alkaline catalysts such as generation of wastewater, catalyst deactivation, difficulty in the separation of biodiesel from catalyst and glycerin, etc. To limit the problems mentioned above, in this study, biodiesel is produced by a non-catalytic using C2H5OH. The effect of experimental variables (the molar ratio ethanol/oil of 41.18:1 – 46.82:1, reaction times of 50 - 90 minutes and reaction temperatures of 2750C - 2950C) on the yield of biodiesel was studied. The 96% yield of Cambodia biodiesel of reaction between C2H5OH and Jatropha Oil at 46:1 at temperature 2900C at 60 minutes no using catalysts. Obtained biodiesel fuel was up to the International Standard ASTM D6751 for biodiesel fuel blend stock (B100).

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