scholarly journals Alcoholysis of Nyamplung Seed Oil Using Potassium Carbonate Catalyst

2006 ◽  
Vol 6 (2) ◽  
pp. 66
Author(s):  
Sofiyah Sofiyah
Keyword(s):  
Potassium Carbonate ◽  
Potassium Hydroxide ◽  
Seed Oil ◽  
Catalyst Concentration ◽  
Order Reaction ◽  
First Order ◽  
Rate Of Reaction ◽  
Glycerine Content ◽  
Sodium And Potassium ◽  
Good Agreement

The production of glycerol and ester by alcoholysis of vegetable oils has been widely studied. Various catalysts, such as sodium and potassium hydroxide and sulfuric acid have been used to increase the rate of reaction. This preliminary research studied the possibility of using potassium carbonate catalyst. The experiment was conducted in an autoclave. A certain amount of nyamplung seed oil was poured into the autoclave and then the heater was switched on to heat up the oil to the required temperature of reaction. Besides, a mixture of ethanol and potassium carbonate was heated in a flask equipped with condenser to form ethanolate. As soon as the required temperature was reached, the ethanolate was quickly put into the autoclave containing the nyamplung seed oil. The temperature of the reaction was kept constant for a period of time. At the end of each process, a sample was withdrawn and analyzed for its glycerine content by acetin method. The variables studied were reaction time and catalyst concentration. The experimental data were evaluated by applying pseudo homogeneous approach. It was found that data were in good agreement with first order reaction with respect to nyamplung seed oil. Using an equivalent ratio of 5.1 ethanol to nyamplung seed oil, a temperature of lOQoC,and an agitation speed of 150 rpm, the favorable catalyst concentration was found to be at 0.008 gram of potassium carbonate per gram of nyamplung seed oil. Under this condition, the glyceride conversion was 0.5159 in 75 min.

scholarly journals KINETICS OF PALM OIL TRANSESTERIFICATION IN METHANOL WITH POTASSIUM HYDROXIDE AS A CATALYST

2010 ◽  
Vol 8 (2) ◽  
pp. 219-225
Author(s):  
Yoeswono Yoeswono ◽  
Triyono Triyono ◽  
Iqmal Tahir
Keyword(s):  
Activation Energy ◽  
Palm Oil ◽  
Rate Constants ◽  
Potassium Hydroxide ◽  
Catalyst Concentration ◽  
Time Interval ◽  
Pseudo First Order Reaction ◽  
Exponential Factor ◽  
Potassium Methoxide ◽  
First Order

A study on palm oil transesterification to evaluate the effect of some parameters in the reaction on the reaction kinetics has been carried out. Transesterification was started by preparing potassium methoxide from potassium hydroxide and methanol and then mixed it with the palm oil. An aliquot was taken at certain time interval during transesterification and poured into test tube filled with distilled water to stop the reaction immediately. The oil phase that separated from the glycerol phase by centrifugation was analyzed by 1H-NMR spectrometer to determine the percentage of methyl ester conversion. Temperature and catalyst concentration were varied in order to determine the reaction rate constants, activation energies, pre-exponential factors, and effective collisions. The results showed that palm oil transesterification in methanol with 0.5 and 1 % w/w KOH/palm oil catalyst concentration appeared to follow pseudo-first order reaction. The rate constants increase with temperature. After 13 min of reaction, More methyl esters were formed using KOH 1 % than using 0.5 % w/w KOH/palm oil catalyst concentration. The activation energy (Ea) and pre-exponential factor (A) for reaction using 1 % w/w KOH was lower than those using 0.5 % w/w KOH.   Keywords: palm oil, transesterification, catalyst, first order kinetics, activation energy, pre-exponential factor

PENYERAPAN GAS KARBONDIOKSIDA (CO 2 ) DALAM BIOGAS DENGAN LARUTAN Ca(OH)2

EKUILIBIUM ◽  
2015 ◽  
Vol 14 (1) ◽  
Author(s):  
Paryanto Paryanto
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Order Reaction ◽  
First Order Reaction ◽  
Glass Ball ◽  
Carbon Dioxide Content ◽  
First Order ◽  
Constant Rate ◽  
Rate Of Reaction ◽  
Reduce Carbon Dioxide

<p>Abstract: Carbon dioxide content in biogas produced by fermentation is still high. Because of<br />that, biogas need a process purification to reduce carbon dioxide content. In this work, Ca(OH)2<br />solution was contacted with biogas in a column for reducing the CO<br />2<br />content. This research<br />studied the effect of packing type used in absorber column on the rate of CO<br />2<br />reduction. Based<br />on experimental data and modelling, it was found that the reaction between CO<br />2<br />followed first order reaction. The constant of rate reaction was affected by the packing type<br />which using glass ball, plastic pipe, ceramic, wood, and clay roof, the constant rate were 0.781,<br />0.464, 0.916, 0.637, and 0.987 min<br />Keywords: Biogas, CO<br />2<br />, Ca(OH)2<br />-1<br />, respectively.<br />, absorber, rate of reaction</p>

scholarly journals Kinetic and Mechanism of Uncatalytic Oxidation of Dl-Threonine by Cerium (Iv) in Aqueous Acid Medium

2021 ◽  
pp. 51-63
Author(s):  
Gajanand Sahu ◽  
Sanjay Ghosh
Keyword(s):  
Thermodynamic Parameters ◽  
Acid Medium ◽  
Rate Constant ◽  
Acidic Medium ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Aqueous Acid ◽  
Rate Of Reaction ◽  
Different Temperatures

Kinetic of uncatalyzed oxidation of DL-Threonine has been studied by Ce (IV) in acidic medium has been investigatigated by spectrophotometer technique.  The rate of reaction determined at three different temperatures ranging from 298 K to 318 K at the interval of 10 K. The reaction has been found to be a first order reaction in presence or in absence of KCl, CTAB, and SDS. The rate constant, decreases with increasing the concentration of [HSO4-] and [H+] ion. The various thermodynamic parameters were calculated at 298 K, 308 K and 318 K. The proposed mechanism and results is discussed.

scholarly journals LAJU HIDROLISIS HEROIN DALAM AIR DAN PLASMA

Jurnal Kimia ◽  
2019 ◽  
pp. 191
Author(s):  
I M. A. G. Wirasuta ◽  
M. A. Ningtyas ◽  
E. I. Setyawan
Keyword(s):  
Mobile Phase ◽  
Limit Of Detection ◽  
Order Reaction ◽  
The Other ◽  
Hydrolysis Rate ◽  
Half Time ◽  
Limit Of Quantification ◽  
First Order ◽  
Rate Of Reaction ◽  
Tlc Separation

Heroine is hydrolyzed spontaneously in water and plasma. This will influence the determination, especially on the drug profiling. Spectrophotodensitometry has been used to analyze drug profiling of illicit heroine. This article reports the AL-TLC separation of heroine, 6-monoacetylmorphine (6-MAM), morphine, acetyl codeine, and the heroine hydrolysis in water and plasma. Heroin, 6-MAM, morphine, and acetyl codeine can be well-separated by mobile phase of toluene:siclohexane:diethyl amine (75:15:10, v/v). The limit of detection was 165.16 ng/spot and the limit of quantification was 550.55 ng/spot. Heroine was hydrolyzed in water and plasma under first order reaction. The rate of reaction was 0.55 min-1 in water with the half time reaction of 12.47 minutes. On the other hand the hydrolysis rate in plasma was slower with the half time of 16 minutes.   Keywords : hydrolysis, heroin, water, TLC-spectrophotodensitometer

scholarly journals Critical ignition conditions in exothermically reacting systems: first-order reactions

2017 ◽  
Vol 473 (2206) ◽  
pp. 20170145 ◽  
Author(s):  
Valeriy Yu. Filimonov
Keyword(s):  
Experimental Data ◽  
Order Reaction ◽  
Critical Conditions ◽  
Conversion Degree ◽  
First Order ◽  
Critical Ignition ◽  
Reacting Systems ◽  
Plane Temperature ◽  
Temperature Time ◽  
Good Agreement

In this paper, the comparative analysis of the thermal explosion (TE) critical conditions on the planes temperature–conversion degree and temperature–time was conducted. It was established that the ignition criteria are almost identical only at relatively small values of Todes parameter. Otherwise, the results of critical conditions analysis on the plane temperature–conversion degree may be wrong. The asymptotic method of critical conditions calculation for the first-order reactions was proposed (taking into account the reactant consumption). The degeneration conditions of TE were determined. The calculation of critical conditions for specific first-order reaction was made. The comparison of the analytical results obtained with the results of numerical calculations and experimental data showed that they are in good agreement.

scholarly journals Transesterification of Lactic Acid Oligomers with Ethanol, a Way to Anhydrous Ethyl Lactate: A Kinetic Study

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2044
Author(s):  
Silvestr Figalla ◽  
Jaroslav Petrůj ◽  
Tereza Švestková
Keyword(s):  
Lactic Acid ◽  
Reaction Rate ◽  
Catalyst Concentration ◽  
Equilibrium Constants ◽  
Equilibrium Composition ◽  
Alcohol Concentration ◽  
Order Reaction ◽  
First Order ◽  
Equilibrium Reactions ◽  
Rate Of Consumption

A new method for the preparation of anhydrous ethyl ester of lactic acid was studied. The selected method is based on catalytic transesterification of lactic acid oligomers, which were prepared for this purpose by autocatalytic oligomerization of lactic acid. In this work, a kinetic model for the case of catalytic alcoholysis of oligoesters was derived assuming a first-order reaction and equimolar content of reactants in the reaction mixture. The model makes it possible to obtain the values of the reaction rate and equilibrium constants and the equilibrium alcohol concentration by regression analysis at one time. The model was verified by measuring the rate of consumption of ethanol over the time at various reaction temperatures with anhydrous FeCl3 as the catalyst. The reaction was studied at overpressure under autogenous conditions in the temperature range of 100–180 °C. For the catalyst concentration of 1 mol %, the activation energy value was 64.35 kJ·mol−1. The dependence of equilibrium composition and rate constant on the temperature was obtained. The derived model is generally applicable to all first-order equilibrium reactions. The presumption is that the forward and reverse reactions are of the same order and have the same stoichiometry and equivalent amounts of reactants at the beginning of the reaction.

Fabrication of Self-Organized TiO2 Nanotubes by Anodization and its Photocatalytic Properties

2011 ◽  
Vol 322 ◽  
pp. 209-212
Author(s):  
Tian Yu Wu ◽  
Xin Tan ◽  
Juan Ru Huang ◽  
Tao Yu ◽  
Lin Zhao
Keyword(s):  
Apparent Rate Constant ◽  
Photocatalytic Performance ◽  
Anatase Phase ◽  
Order Reaction ◽  
Nanotube Arrays ◽  
Photocatalytic Reaction ◽  
First Order ◽  
Self Organized ◽  
Titania Nanotube Arrays ◽  
Good Agreement

Titania nanotube arrays(TNT) was extensively studied due to its good photocatalytic activity. This article focused on the fabrication of highly ordered TNTs. TNTs were fabricated in an electrolyte of ethylene glycol(EG), water and NH4F for 1, 2, 3, 4h and then annealed at 400°C. The influence of anodic time on the morphology and photocatalytic performance of TNT was investigated. The results indicated that the TNT could be successfully fabricated by using the electrolyte, and the diameter and length of TNT were about approximately 140nm, 5-13μm, separately. Furthermore, the results also showed anatase phase was dominant, TNT with good morphology displayed good photocatalitic properties. When the initial concentration of Rhodamine B(RhB) was 7×10−6mol﹒L−1, the removal of RhB reached 88.1% by TNT anodized for 2h with length of 9.5μm. In addition, the results showed that the photocatalytic reaction fitting the first-order reaction in good agreement with the literature, and the apparent rate constant(kapp) was 0.0251 min-1(the length of 9.5μm)．

Leaching Kinetics of Atrazine and Inorganic Chemicals in Tilled and Orchard Soils

2014 ◽  
Vol 28 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Lech W. Szajdak ◽  
Jerzy Lipiec ◽  
Anna Siczek ◽  
Artur Nosalewicz ◽  
Urszula Majewska
Keyword(s):  
Reaction Rate ◽  
Inorganic Compounds ◽  
Model Performance ◽  
Order Reaction ◽  
First Order Reaction ◽  
Order Kinetic ◽  
Time Data ◽  
First Order ◽  
Concentration Changes ◽  
Reaction Constants

Abstract The aim of this study was to verify first-order kinetic reaction rate model performance in predicting of leaching of atrazine and inorganic compounds (K+1, Fe+3, Mg+2, Mn+2, NH4 +, NO3 - and PO4 -3) from tilled and orchard silty loam soils. This model provided an excellent fit to the experimental concentration changes of the compounds vs. time data during leaching. Calculated values of the first-order reaction rate constants for the changes of all chemicals were from 3.8 to 19.0 times higher in orchard than in tilled soil. Higher first-order reaction constants for orchard than tilled soil correspond with both higher total porosity and contribution of biological pores in the former. The first order reaction constants for the leaching of chemical compounds enables prediction of the actual compound concentration and the interactions between compound and soil as affected by management system. The study demonstrates the effectiveness of simultaneous chemical and physical analyses as a tool for the understanding of leaching in variously managed soils.

The Kinetics of Glucose Decomposition with Sulfate Reduction in the Anaerobic Fluidized Bed Reactor

1993 ◽  
Vol 28 (2) ◽  
pp. 135-144 ◽  
Author(s):  
S. Matsui ◽  
R. Ikemoto Yamamoto ◽  
Y. Tsuchiya ◽  
B. Inanc
Keyword(s):  
Sulfate Reduction ◽  
Fluidized Bed ◽  
Kinetic Equations ◽  
Fluidized Bed Reactor ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Glucose Decomposition ◽  
Reaction Equations ◽  
Kinetics Of

Using a fluidized bed reactor, experiments on glucose decomposition with and without sulfate reduction were conducted. Glucose in the reactor was mainly decomposed into lactate and ethanol. Lactate was mainly decomposed into propionate and acetate, while ethanol was decomposed into propionate, acetate, and hydrogen. Sulfate reduction was not involved in the decomposition of glucose, lactate, and ethanol, but was related to propionate and acetate decomposition. The stepwise reactions were modeled using either a Monod expression or first order reaction kinetics in respect to the reactions. The coefficients of the kinetic equations were determined experimentally. The modified Monod and first order reaction equations were effective at predicting concentrations of glucose, lactate, ethanol, propionate, acetate, and sulfate along the beight of the reactor. With sulfate reduction, propionate was decomposed into acetate, while without sulfate reduction, accumulation of propionate was observed in the reactor. Sulfate reduction accelerated propionate conversion into acetate by decreasing the hydrogen concentration.

The effect of polymeric and model imidazolium halides on the rate of hydrolysis of 4-acetoxy-3-nitrobenzoic acid

1985 ◽  
Vol 50 (4) ◽  
pp. 845-853 ◽  
Author(s):  
Miloslav Šorm ◽  
Miloslav Procházka ◽  
Jaroslav Kálal
Keyword(s):  
Catalyst Concentration ◽  
Low Molecular Weight ◽  
Imidazolium Chloride ◽  
First Order ◽  
Nitrobenzoic Acid ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Hydrolysis Of ◽  
Ethanol In Water ◽  
Direct Attack

The course of hydrolysis of an ester, 4-acetoxy-3-nitrobenzoic acid catalyzed with poly(1-methyl-3-allylimidazolium bromide) (IIa), poly[l-methyl-3-(2-propinyl)imidazolium chloride] (IIb) and poly[l-methyl-3-(2-methacryloyloxyethyl)imidazolium bromide] (IIc) in a 28.5% aqueous ethanol was investigated as a function of pH and compared with low-molecular weight models, viz., l-methyl-3-alkylimidazolium bromides (the alkyl group being methyl, propyl, and hexyl, resp). Polymers IIb, IIc possessed a higher activity at pH above 9, while the models were more active at a lower pH with a maximum at pH 7.67. The catalytic activity at the higher pH is attributed to an attack by the OH- group, while at the lower pH it is assigned to a direct attack of water on the substrate. The rate of hydrolysis of 4-acetoxy-3-nitrobenzoic acid is proportional to the catalyst concentration [IIc] and proceeds as a first-order reaction. The hydrolysis depends on the composition of the solvent and was highest at 28.5% (vol.) of ethanol in water. The hydrolysis of a neutral ester, 4-nitrophenyl acetate, was not accelerated by IIc.

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