scholarly journals Catalytic Synthesis of Levulinate Esters over Zirconia and its Modified Forms Coated on Honeycomb Monoliths: Green Synthesis

2019 ◽  
Vol 31 (9) ◽  
pp. 1993-1999
Author(s):  
Reena Saritha Serrao ◽  
S.Z. Mohamed Shamshuddin ◽  
Joyce D'souza

A series of solid acid catalysts such as ZrO2, Mo(VI)/ZrO2 and W(VI)/ZrO2 have been coated on honeycomb monoliths as well as synthesized in the powder forms and used as catalytic materials for synthesis of ethyl levulinate from levulinic acid and ethanol. These solid acids were characterized by BET, NH3-TPD/n-butyl amine back titration, FTIR, PXRD and SEM techniques. Effects of various reaction parameters towards the reaction performance were studied. The performance of the catalyst was tested based on nature of the catalyst (honeycomb coated or powder form), reaction time (1 to 5 h), molar ratio (1:1 to 1:12 levulinic acid to ethanol) and reusability of the catalytic material. An excellent yield (86-88 %) of ethyl levulinate was obtained under optimized conditions. An attempt is made to correlate the activity of the catalysts in this esterification reaction with their surface characteristics. The honeycomb monoliths coated with zirconia and its modified forms were found to be ecofriendly, cost-effective and reusable catalytic materials compared to their powder forms.

2013 ◽  
Vol 743-744 ◽  
pp. 198-203
Author(s):  
Qi Dong Liu ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Ya Li Wang ◽  
Yun Feng Zhang

The MnOX-CeO2/TiO2 catalytic material for low temperature SCR of NOX with NH3 was prepared using aqueous solutions of three manganese salt as well as cerous nitrate and TiO2(anatase) powder by impregnation method. The properties of the catalytic materials were investigated by TG-DSC, XRF, XRD, XPS, BET and SEM. And the low temperature catalytic activity of the catalytic materials was measured. The results showed that, when manganese nitrate and manganese chloride and manganese acetate were used as precursors, respectively, the primary phases of catalytic materials were MnOx/MnO2, MnO2/Mn8O10Cl3 and Mn3O4/MnO2, the surface Mn/Ti molar ratio were 0.68, 0.19 and 0.88, the surface area were 45.1m2/g, 25.1 m2/g and 48.6 m2/g ,respectively. The optimum NOX conversion rate of catalytic material from manganese nitrate precursor and manganese chloride precursor and manganese acetate precursor were 97.9% at 483K, 86.6% at 513K, 97.2% at 423K, respectively. Consequently, the higher low-temperature activity of MnOX-CeO2/TiO2 from manganese acetate precursor may be attributed to higher surface and higher surface concentration of activity component.


Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1684
Author(s):  
Carmelina Rossano ◽  
Claudio Luigi Pizzo ◽  
Riccardo Tesser ◽  
Martino Di Serio ◽  
Vincenzo Russo

Levulinic acid (LA) has been highlighted as one of the most promising platform chemicals, providing a wide range of possible derivatizations to value-added chemicals as the ethyl levulinate obtained through an acid catalyzed esterification reaction with ethanol that has found application in the bio-fuel market. Being a reversible reaction, the main drawback is the production of water that does not allow full conversion of levulinic acid. The aim of this work was to prove that the chromatographic reactor technology, in which the solid material of the packed bed acts both as stationary phase and catalyst, is surely a valid option to overcome such an issue by overcoming the thermodynamic equilibrium. The experiments were conducted in a fixed-bed chromatographic reactor, packed with Dowex 50WX-8 as ion exchange resin. Different operational conditions were varied (e.g., temperature and flow rate), pulsing levulinic acid to the ethanol stream, to investigate the main effects on the final conversion and separation efficiency of the system. The effects were described qualitatively, demonstrating that working at sufficiently low flow rates, LA was completely converted, while at moderate flow rates, only a partial conversion was achieved. The system worked properly even at room temperature (303 K), where LA was completely converted, an encouraging result as esterification reactions are normally performed at higher temperatures.


Author(s):  
E. El Zanati ◽  
H. Abdallah ◽  
G. Elnahas

Abstract Y-shape micro-reactor is designed, developed and implemented to investigate the effect of reactor miniaturization on chemical engineering kinetics, where, an esterification reaction of fatty acid (2- ethyl hexanoic acid) is considered as a case study. In order to investigate the differential change of micro-reaction conversion along the channel axis; a micro-reactor with multi-channel is designed in a manner that enables collecting the samples. The kinetics of esterification reaction of ethanol and fatty acid was explored under various operating conditions; Molar Ratio (MR) of ethanol to fatty acid at temperatures 25–65 °C. The conversion reached almost 99.3 % after 30 s at MR 4:1 and 25 °C. Steady and unsteady state axial dispersion mathematical models were developed; the latter approach resulted in fair agreement with the experimental results.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Angélica M. Escobar ◽  
Mirta N. Blanco ◽  
José J. Martínez ◽  
Jairo A. Cubillos ◽  
Gustavo P. Romanelli ◽  
...  

Magnetic materials based on Keggin heteropolyacids immobilized on mesoporous silica-coated magnetite particles with a core-shell structure were synthesized. The activity of the catalyst was studied in the esterification reaction of levulinic acid with n-butanol, and its kinetics was studied by the systematic variation of several reaction parameters, such as stirring speed, catalyst loading, molar ratio of reactants, and temperature. It was also seen that the reaction was free from any external mass transfer as well as intraparticle diffusion limitations and was intrinsically kinetically controlled. A second-order kinetic equation was found to be consistent with the experimental data. Also, an experimental activation energy of 17 kcal/mol was found. A solvent-free condition for this reaction has also added the green chemistry perception to the reaction. In addition, the resulting catalyst can be used repeatedly without significant decrease in activity.


Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 427 ◽  
Author(s):  
Muhammad Awais ◽  
Sa’ed A Musmar ◽  
Faryal Kabir ◽  
Iram Batool ◽  
Muhammad Asif Rasheed ◽  
...  

Biodiesel is a renewable fuel usually produced from vegetable oils and animal fats. This study investigates the extraction of oil and its conversion into biodiesel by base-catalyzed transesterification. Firstly, the effect of various solvents (methanol, n-hexane, chloroform, di-ethyl ether) on extraction of oil from non-edible crops, such as R. communis and M. azedarach, were examined. It was observed that a higher concentration of oil was obtained from R. communis (43.6%) as compared to M. azedarach (35.6%) by using methanol and n-hexane, respectively. The extracted oils were subjected to NaOH (1%) catalyzed transesterification by analyzing the effect of oil/methanol molar ratio (1:4, 1:6, 1:8 and 1:10) and varying temperature (20, 40, 60 and 80 °C) for 2.5 h of reaction time. M. azedarach yielded 88% and R. communis yielded 93% biodiesel in 1:6 and 1:8 molar concentrations at ambient temperature whereas, 60 °C was selected as an optimum temperature, giving 90% (M. azedarach) and 94% (R. communis) biodiesel. The extracted oil and biodiesel were characterized for various parameters and most of the properties fulfilled the American Society for Testing and Materials (ASTM) standard biodiesel. The further characterization of fatty acids was done by Gas Chromatography/Mass Spectrometer (GC/MS) and oleic acid was found to be dominant in M. azedarach (61.5%) and R. communis contained ricinoleic acid (75.53%). Furthermore, the functional groups were analyzed by Fourier Transform Infrared Spectroscopy. The results suggested that both of the oils are easily available and can be used for commercial biodiesel production at a cost-effective scale.


2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao

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.


Author(s):  
Jilei Chao ◽  
Ruizhi Shi ◽  
Fuqiang Chu ◽  
Yanling Guo ◽  
Qian Deng

A kind of waterborne varnish for inkjet printing was synthesized, and properties of the waterborne varnish were characterized to make it suitable for the glazing requirements of inkjet printing and other printability requirements. The waterborne varnish was synthesized from epoxy resin (E-51), epoxy diluent (ED), acrylic acid, trimellitic anhydride, maleic anhydride and organic amine by three steps of ring opening reaction, esterification reaction, neutralization reaction. The viscosity, film-forming property, water absorption of waterborne varnish and the water resistance, lightness, wear resistance and bonding strength of coated paper were tested. The effects of the ratio of E-51 and ED in the polymerization system on the properties of waterborne varnish were studied. In the test of printability of self-made waterborne varnish, the absorption of digital inkjet paper to varnish and the influence of varnish on color reproduction of printed image were discussed and studied. The results show that when the molar ratio of epoxy group in E-51 and ED is about 1:1, the prepared varnish is suitable for inkjet printing, and its film-forming property, such as water resistance, adhesion and friction resistance are better. At the same time, its printability is also better.


2014 ◽  
Vol 900 ◽  
pp. 361-364
Author(s):  
Xiao Hui Wang ◽  
Xi Hua Du ◽  
Li Min Dong

Esters of Citric acid and palmityl alcohol were synthesized by esterification reaction under catalysis of cation exchange resin and P-toluene sulfonic acid respectively. The effects of amount of catalyst, ratio of raw materials, reaction time and temperature on the synthesis reaction were investigated . The experimental results showed that optimum of process conditions were 1:1~1:1.5 molar ratio of citric acid and palmityl alcohol, reaction temperature of 130~140°C, reaction time of 2 h. Conversion of palmityl alcohol were all more than 90% under 0.3% dosage using p-toluene sulfonic acid as the catalyst, or 0.5% dosage using 721 cation exchange resin with sulfonic acid type as catalyst. The synthesized product had good surface activity.


Author(s):  
Bing Ge ◽  
Shu-sheng Zang ◽  
Yinsheng Tian ◽  
Dong-fang Zhang ◽  
Yao-xin Cui ◽  
...  

The development of integrated gasification combined cycle (IGCC) systems provides cost-effective and environmentally sound options for meeting future coal-utilizing power generation needs in the world. The combustion of gasified coal fuel significantly influences overall performance of IGCC power generation. Experimental measurements are carried out on a non-premixed model combustor, equipped with a double-swirled syngas burner. Planar laser-induced fluorescence (PLIF) of OH radical measurement is adopted to identify main reaction zones and burnt gas regions as well. Together with the temperature and emission measurements during the exhaust section, some important characteristics of the syngas flame are investigated overall. In this paper, the effects of the CO/H2 molar ratio consisting of syngas fuel are investigated under different humidity. With the increase of CO/H2 ratios, the concentration field of OH radicals is gradually away from the nozzle exit, and the nozzle exit almost no existence of OH radicals, forming a typical lifted flame. In addition, fluorescent signal strength of OH radicals pronounced weakening, the flame gradually appeared W type distribution and more and more obvious with the increased of humidification amount. At the same time the average exhaust temperature of combustor CO and NOx missions almost no change. The study can provide a reliable database for high moisture gas turbine combustor design and combustion numerical simulation.


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