scholarly journals BIOFUEL VIA INTERESTERIFICATION OF RAPESEED OIL WITH METHYL ACETATE IN PRESENCE OF POTASSIUM t-BUTOXIDE/THF

2019 ◽  
Vol 1 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Valdis Kampars ◽  
Zane Abelniece ◽  
Ruta Kampare
Keyword(s):  
Catalytic System ◽  
Sodium Methoxide ◽  
Rapeseed Oil ◽  
Methyl Acetate ◽  
Side Reaction ◽  
Conversion Process ◽  
Homogeneous Catalyst ◽  
Hydroxyl Groups ◽  
Full Conversion ◽  
Alcoholic Hydroxyl

Transesterification does not allow to make full conversion of oil to biodiesel because the by-product glycerol cannot be included in the composition of biofuel. Interesterification constitutes a full conversion process with production of triacetin (TA) instead of glycerol, which can be included in the composition of biofuel and allows to increase its yield. Both interesterification and transesterification effectively occur only in presence of catalysts. Results of the investigation of heterogeneous and homogeneous catalysts indicate the superior importance of catalyst solubility in starting reaction mixture. Partial solubility can remarkably lower the activity of homogeneous catalyst and extremely increase that of formally heterogeneous one. The reaction mixture of interesterification reaction is less polar than that of transesterification, and potassium tert-butoxide (t-BuOK) should be more appropriate catalyst for interesterification than sodium methoxide which is used in most cases. The catalytic system t-BuOK/t-BuOH substantially increases the yield of TA and changes the properties of obtained biofuel. Whereas the content of the TA in the interesterification reaction mixture does not achieve the same level from the theoretically predicted as the FAME, the occurrence of side reaction between t-BuOH and TA cannot be excluded. This paper presents a study of the interesterification of rapeseed oil in presence of catalytic system t-BuOK/THF (catalytic system without alcohols) with the aim of establishing the influence of aprotic tetrahydrofuran to the proceeding the reaction, composition of reaction mixtures and their fuel properties. Obtained results show that the absence of alcoholic hydroxyl groups in the catalytic system insufficiently increases the activity of catalytic system but fails to increase the yield of FAME.

Competitive Interesterification-Transesterification of Rapeseed Oil with Methyl Acetate in Presence of Potassium Metoxide Solutions

2018 ◽  
Vol 762 ◽  
pp. 158-162 ◽  
Author(s):  
Elina Sile ◽  
Valdis Kampars ◽  
Zane Sustere
Keyword(s):  
Catalytic System ◽  
Rapeseed Oil ◽  
Methyl Acetate ◽  
Catalytic Systems ◽  
Tert Butanol

Two catalytic systems (CH3OK/CH3OH and CH3OK/tert-BuOH) were tested to estimate competitive interesterification-transesterification processes of rapeseed oil with methyl acetate. Catalyst completely dissolves in methanol, while in tert-butanol suspension was obtained. With CH3OK/CH3OH catalytic system high FAME content was obtained (86 wt%), but triacetin content was negligible and without FAME mostly transesterification products of oil and triacetin were observed (up to 94 wt% of all products). When CH3OK/tert-BuOH catalytic system was used, only interesterification of oil proceeded, nevertheless the composition of product complicated the interesterification of triacetin with tert-butanol.

scholarly journals Effect of Temperature on Interesterification of Rapeseed Oil with Methyl Acetate in Presence of BuOK/BuOH

2019 ◽  
Vol 103 ◽  
pp. 02006
Author(s):  
Valdis Kampars ◽  
Reinis Gravins ◽  
Kristine Lazdovica ◽  
Ruta Kampare
Keyword(s):  
Reaction Time ◽  
Rapeseed Oil ◽  
Methyl Acetate ◽  
Order Rate Constant ◽  
Effect Of Temperature ◽  
Molar Ratio ◽  
Optimal Range ◽  
First Order ◽  
Pseudo First Order ◽  
Full Conversion

If the interesterification reaction of rapeseed oil with methyl acetate at reactant to oil molar ratio of 18:1 in presence of potassium tert-butoxide in tert-butanol of molar ratio to oil 0.08 is conducted at a temperature of about 35 °C, reaction time for full conversion of oil is shorter than one hour, while at a temperature of 55 °C it is approximately 15 minutes. Reaction time at the desired temperature has a wide "optimal" range and cannot be an effective variable for the process optimisation. Experimental results at the temperature of 25 °C confirm the pseudo-first order of the reaction, which lowered towards the end of the reaction. The pseudo-first order rate constant was 0.63 min-1. Fuel characteristics of the interesterification reaction mixtures without purification improved with the rising of reaction temperature from 35 °C to 55 °C, however, they fail to meet the requirements of standard EN14214 for biodiesel. Methyl acetate to oil molar ratio 18:1 is too low for obtaining products with kinematic viscosity below 5.0 mm2/s.

scholarly journals Titanium Dioxide Modified with Alcoholic Hydroxyl Groups

1994 ◽  
Vol 67 (8) ◽  
pp. 489-495 ◽  
Author(s):  
Tsuneo SUHARA ◽  
Hiroshi HUKUI ◽  
Michihiro YAMAGUCHI
Keyword(s):  
Titanium Dioxide ◽  
Hydroxyl Groups ◽  
Alcoholic Hydroxyl

scholarly journals Synthesis and biotical activity of bacterial cellulose 6-(2-phthalimidoethanesulfonate)

2020 ◽  
Vol 61 (2) ◽  
pp. 29-36
Author(s):  
Zoya P. Belousova ◽  
Keyword(s):  
Bacterial Cellulose ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Cellulose Derivatives ◽  
Wound Surface ◽  
Reaction Products ◽  
Absorption Bands ◽  
Hydroxymethyl Group ◽  
Antibacterial And Antifungal

Bacterial cellulose obtained by culturing Gluconacetobacter sucrofermentans in HS environment was converted to sulfonate derivatives using methane-, toluene- and 2-phthalimidoethanesulfonic acids in pyridine. When the ratio of the starting reagents is 1 : 1, the modification of bacterial cellulose according to the primary hydroxyl group of glucopyranose fragments is most likely. The formation of 6-substituted bacterial cellulose derivatives was observed in the reaction mixture. The IR spectra of the reaction products contain absorption bands, which are specific for (O–SO2) group in the region 1377-1338 cm−1 (as), 1178-1154 cm−1 (s), fragments of the corresponding sulfonic acids, as well as free hydroxyl groups of glucopyranose in the region 3495-3382 cm−1. Bacterial cellulose 2-phthalimidoethanesulfonate was dissolved in pyridine. After drying with a desiccant in a desiccator, it turned into a dense transparent film of brown color. The increased molecular film allows to explain the side reaction occurring between the oxo group and fragments of one of the chains of modified cellulose and the non-substituted hydroxymethyl group. The IR spectrum of bacterial cellulose 6-(2-phthalimidoethanesulfonate) contains absorption bands in the region 1711 cm−1, which are specific for (Ar–CO–O) group, and absorption bands in the region 1618 cm−1, which prove the presence of (CO–NH) group. In order to impart antibiotic properties to the bacterial cellulose 6-(2-phthalimido-ethanesulfonate) film, it was physically modified with clotrimazole. The obtained experimental data showed that the films subjected to treatment with a 1% solution of clotrimazole have antibacterial and antifungal effects and prevent the growth of pathogenic microbiota on the wound surface. The exit rates of clotrimazole from the bacterial cellulose 6-(2-phthalimidoethanesulfonate) film and from the pure bacterial cellulose film differed, but only slightly. 2-Phthalimidoethanesulfonate bacterial cellulose films can be used to form composites of effective wound covering, since in addition to the unique properties of bacterial cellulose itself (low allergenicity and adhesion to the wound surface, high hygroscopicity) they will have a regenerating effect.

GAS–LIQUID CHROMATOGRAPHY OF TERPENES: PART III. THE USE OF OLEIC ACID ESTERS AS LIQUID PHASES

1961 ◽  
Vol 39 (6) ◽  
pp. 1190-1199 ◽  
Author(s):  
E. von Rudloff
Keyword(s):  
Liquid Phase ◽  
Rapeseed Oil ◽  
Hydroxyl Groups ◽  
Gas Liquid Chromatography ◽  
Retention Data ◽  
Geometrical Isomers ◽  
Potassium Oleate ◽  
Liquid Phases ◽  
Degree Of Separation ◽  
Poly Ethylene

The separation of several cyclic terpene hydrocarbons and some oxygenated derivatives was studied on a variety of triglyceride and dioleate ester columns. Use of rapeseed oil, partially hydrogenated rapeseed oil, olive oil, triolein, tristearin, methyl oleate, and potassium oleate as liquid phases led to the conclusion that the presence of an esterified mono-unsaturated long-chain acid is a desirable constituent of the liquid phase. Dioleate esters of 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and polyethylene glycol showed useful differences in the degree of separation of both terpene hydrocarbons and oxygenated derivatives. Ether linkages, as in the di- and poly-ethylene glycol ester, also were associated with favorable separations. When the liquid phase contained free hydroxyl groups, the degree of separation of hydrocarbons and ketones was in general less favorable. The spacing of the ester groups was found to have some effect on retention data. The separation of such critical pairs of isomers as tricyclene and α-pinene, α-fenchene and camphene, and also geometrical isomers of oxygenated derivatives is facilitated by use of several of these liquid phases.

Chemical Characteristics of Humic Compounds Isolated From Some Decomposed Marine Algae

1972 ◽  
Vol 29 (1) ◽  
pp. 55-60 ◽  
Author(s):  
M. A. Rashid ◽  
A. Prakash
Keyword(s):  
Molecular Weight ◽  
Fulvic Acids ◽  
Structural Features ◽  
Hydroxyl Groups ◽  
Laminaria Digitata ◽  
Carbon And Nitrogen ◽  
Humic Compounds ◽  
Spectroscopic Characteristics ◽  
Nitrogen Contents ◽  
Alcoholic Hydroxyl

The chemical and spectroscopic characteristics of humic compounds isolated from decomposed thalli of Fucus vesiculosus and Laminaria digitata, seaweed exudate, and dissolved organic matter in river water show that, in spite of several differences, their gross structural features are similar to those of humic compounds isolated from marine sediments or soils. Dominant functional groups are carboxyl and carbonyl but phenolic and alcoholic hydroxyl groups are also present in small proportions. Between 20 and 40% of humic acids are represented by fractions having molecular weight greater than 200,000, whereas the fulvic acids do not exceed 10,000. Carbon and nitrogen contents show a direct relation with molecular weight whereas the oxygen is inversely related.

scholarly journals Synthesis of 1,5-Functionalized 1,2,3-Triazoles Using Ionic Liquid/Iron(III) Chloride as Efficient and Reusable Homogeneous Catalyst

2018 ◽  
Author(s):  
Antonio De Nino ◽  
Pedro Merino ◽  
Vincenzo Algieri ◽  
Monica Nardi ◽  
Maria Luisa Di Gioia ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Liquid Iron ◽  
Catalytic System ◽  
Dipolar Cycloaddition ◽  
Homogeneous Catalyst ◽  
Mechanistic Studies ◽  
Elimination Process ◽  
Cheap Method

An efficient, eco-compatible and very cheap method for the construction of triazoles via eliminative azide–olefin cycloaddition (EAOC) reaction has been developed by a catalytic system IL/FeCl3, offering an highly regioselective approach to structurally diverse 1,5-disubstituted 1,2,3-triazoles in up to 95% yield. This strategy features the reuse of catalytic system through simple operations. Mechanistic studies indicated that an asynchronous concerted dipolar cycloaddition-elimination process might be involved.

Interesterification of rapeseed oil with methyl acetate in the presence of potassium tert-butoxide solution in tetrahydrofuran

2020 ◽  
Vol 158 ◽  
pp. 668-674
Author(s):  
Valdis Kampars ◽  
Zane Abelniece ◽  
Kristine Lazdovica ◽  
Ruta Kampare
Keyword(s):  
Rapeseed Oil ◽  
Methyl Acetate
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