Esterification and ketalization of levulinic acid with desilicated zeolite β and pseudo-homogeneous model for reaction kinetics

2019 ◽  
Vol 51 (4) ◽  
pp. 299-308 ◽  
Author(s):  
Vaishali Umrigar ◽  
Mousumi Chakraborty ◽  
Parimal Parikh
Keyword(s):  
Reaction Kinetics ◽  
Levulinic Acid ◽  
Homogeneous Model ◽  
Zeolite Β

scholarly journals Reaction Kinetics of Levulinic Acid Synthesis from Glucose Using Bronsted Acid Catalyst

2021 ◽  
Author(s):  
Meutia Ermina Toif ◽  
Muslikhin Hidayat ◽  
Rochmadi Rochmadi ◽  
Arief Budiman
Keyword(s):  
Reaction Kinetics ◽  
Glucose Concentration ◽  
Levulinic Acid ◽  
Acid Catalyst ◽  
Operating Conditions ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Initial Glucose Concentration ◽  
Brönsted Acid ◽  
Kinetics Of

Abstract Glucose is the primary derivative of lignocellulosic biomass, which is abundantly available. Glucose has excellent potential to be converted into valuable compounds such as ethanol, sorbitol, gluconic acid, and levulinic acid (LA). Levulinic acid is a very promising green platform chemical. It is composed of two functional groups, ketone and carboxylate groups which can act as highly reactive electrophiles for nucleophilic attack so it has extensive applications, including fuel additives, raw materials for the pharmaceutical industry, and cosmetics. The reaction kinetics of LA synthesis from glucose using hydrochloric acid catalyst (bronsted acid) were studied in a wide range of operating conditions, i.e., temperature of 140-180 oC, catalyst concentration of 0.5-1.5 M, and initial glucose concentration of 0.1-0.5 M. The highest LA yield is 48.34 %wt at 0.1 M initial glucose concentration, 1 M HCl, and temperature of 180 oC. The experimental results show that the bronsted acid catalyst's reaction pathway consists of glucose decomposition to levoglucosan (LG), conversion of LG to 5-hydroxymethylfurfural (HMF), and rehydration of HMF to LA. The experimental data yields a good fitting by assuming a first-order reaction model.

scholarly journals Reaction Kinetics of Levulinic Acid Synthesis from Glucose Using Bronsted Acid Catalyst

2021 ◽  
Vol 16 (4) ◽  
pp. 904-915
Author(s):  
Meutia Ermina Toif ◽  
Muslikhin Hidayat ◽  
Rochmadi Rochmadi ◽  
Arief Budiman
Keyword(s):  
Reaction Kinetics ◽  
Glucose Concentration ◽  
Levulinic Acid ◽  
Operating Conditions ◽  
Nucleophilic Attack ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Initial Glucose Concentration ◽  
Brönsted Acid ◽  
Kinetics Of

Glucose is one of the primary derivative products from lignocellulosic biomass, which is abundantly available. Glucose has excellent potential to be converted into valuable compounds such as ethanol, sorbitol, gluconic acid, and levulinic acid (LA). Levulinic acid is an exceptionally promising green platform chemical. It comprises two functional groups, ketone and carboxylate, acting as highly reactive electrophiles for a nucleophilic attack. Therefore, it has extensive applications, including fuel additives, raw materials for the pharmaceutical industry, and cosmetics. This study reports the reaction kinetics of LA synthesis from glucose catalyzed by hydrochloric acid (HCl), a Bronsted acid, that was carried out under a wide range of operating conditions; i.e. the temperature of 140–180 °C, catalyst concentration of 0.5–1.5 M, and initial glucose concentration of 0.1–0.5 M. The highest LA yield of 48.34 % was able to be obtained from an initial glucose concentration of 0.1 M and by using 1 M HCl at 180 °C. The experimental results show that the Bronsted acid-catalyzed reaction pathway consists of glucose decomposition to levoglucosan (LG), conversion of LG to 5-hydroxymethylfurfural (HMF), and rehydration of HMF to LA. The experimental data yields a good fitting by assuming a first-order reaction model. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

scholarly journals The Kinetics of Calcium Oxide Catalyzed Esterification of Glycerol with Free Fatty Acids Using Pseudo-homogeneous Model Approach

REAKTOR ◽  
2018 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
Megawati Megawati ◽  
Dhoni Hartanto ◽  
Catur Rini Widyastuti ◽  
Diyah Saras Wati ◽  
Eny Nurhayati
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Reaction Kinetics ◽  
Calcium Oxide ◽  
Homogeneous Model ◽  
Solid Catalyst ◽  
Esterification Reaction ◽  
Oxide Content ◽  
Reaction Constants ◽  
Kinetics Of

Abstract This research aims to study the reaction kinetics of esterification reaction of glycerol with free fatty acid (FFA) using calcium oxide catalyst to produce mono-diacylglycerol (MDAG) using pseudo-homogeneous approach. The effects of time and temperature on the reaction conversion were investigated simultaneously. The FFA used was from the waste of cocoa production process, while the solid catalyst used was calcium oxide from eggshell ash. The results show that the cocoa based FFA was composed of palmitic acid (49.24%), methyl stearate (1.05%), oleic acid (25.39%), and stearic acid (24.32%). The calcium oxide content in the eggshell ash was 60% w/w. At all temperatures studied (60, 70, and 80oC), as the reaction time increased, the conversion increased sharply in the first 5 minute followed by a gradual raise to an almost constant value after 20 minutes (0.844; 0.845; and 0.854, respectively). Pseudo-homogeneous second order model can describe the reaction kinetics satisfactorily. The reaction constants (k) at 60, 70, and 80oC were 0.00384, 0.003401, and 0.003518 (L/mole.minute), respectively. The effects of temperature on reaction rate obey the Arrhenius’ equation with collision factor (A) is 0.2659 (L/mole.minute) and activation energy (Ea) is 3544 J/mol. Keywords: calcium oxide; free fatty acid; glycerol; pseudo-homogeneous approach

scholarly journals Production of levulinic acid from lignocellulosic biomass with a recyclable aromatic acid and its kinetic study

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 725-736 ◽  
Author(s):  
Hairui Ji ◽  
Cuihua Dong ◽  
Guihua Yang ◽  
Zhiqiang Pang
Keyword(s):  
Reaction Kinetics ◽  
Lignocellulosic Biomass ◽  
Levulinic Acid ◽  
Catalyst Concentration ◽  
Maximum Yield ◽  
Aromatic Acid ◽  
Optimum Conditions ◽  
Toluene Sulfonic Acid ◽  
Lower Temperature ◽  
Cellulose Component

Levulinic acid (LA), a renewable and valuable platform chemical from lignocellulosic biomass, has exhibited major potential in the production of biomaterials and biofuels. This study reports the production of LA from lignocellulose using a recyclable aromatic acid, toluene sulfonic acid (p-TsOH), and its reaction kinetics were investigated. The adoption of p-TsOH, which has a special hydrophobic and hydrophilic structure, dramatically improved the yield of LA to a competitive level (57.9±4.1%) at the optimum conditions (reaction temperature = 162 °C, catalyst concentration = 0.95 mol/L, and reaction time = 64 min). Meanwhile, the kinetics involving the simultaneous conversion of both glucan (the cellulose component) and mannan (the hemicellulose component) to LA were examined. The results indicated that the activation energy values in the reaction kinetics were lower than those in previous studies that used H2SO4 as a catalyst. Consequently, the maximum yield of LA was easily obtained at a lower temperature (170 °C). The results of this study are important for process modelling applications and the production of LA from lignocellulosic materials.

Study of C2H5O2 using modulated photolysis: ultra-violet spectrum and self-reaction kinetics in the temperature range 233-363 K

1997 ◽  
Vol 94 ◽  
pp. 484-502
Author(s):  
S Fauvet ◽  
JP Ganne ◽  
J Brion ◽  
D Daumont ◽  
J Malicet ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Ultra Violet ◽  
Temperature Range

SYNTHESIS AND REACTION KINETICS STUDY OF TRI PHENYL PHOSPHITE

2019 ◽  
Vol 2 (2) ◽  
pp. 99-106
Author(s):  
Satish M. Mane ◽  
M. Praharaj Bhatnagar ◽  
M. R. Sawant ◽  
B. N. Thorat
Keyword(s):  
Reaction Kinetics ◽  
Kinetics Study

Impact Of Synthesis Route on the Water Oxidation Kinetics of Hematite Photoanodes

2020 ◽  
Author(s):  
Camilo A. Mesa ◽  
Ludmilla Steier ◽  
Benjamin Moss ◽  
Laia Francàs ◽  
James E. Thorne ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Reaction Kinetics ◽  
Water Oxidation ◽  
Oxidation Kinetics ◽  
Oxidation Reaction ◽  
Charge Accumulation ◽  
Optical Signals ◽  
Current Voltage ◽  
Voltage Performance ◽  
Kinetics Of

<p><i>Operando</i> spectroelectrochemical analysis is used to determine the water oxidation reaction kinetics for hematite photoanodes prepared using four different synthetic procedures. Whilst these photoanodes exhibit very different current / voltage performance, their underlying water oxidation kinetics are found to be almost invariant. Lower photoanode performance was found to correlate with the observation of optical signals indicative of charge accumulation in mid-gap oxygen vacancy states, indicating these states do not contribute directly to water oxidation.</p>

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