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1

Synteza węglanu dimetylu metodą transestryfikacji węglanu propylenu metanolem z zastosowaniem czwartorzędowych soli oniowych i cieczy jonowych jako katalizatorów

Kotyrba Łukasz, Siewniak Agnieszka, Chrobok Anna

Przemysł Chemiczny

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2023

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T. 102, nr 11

1217--1222

PL

Węglan dimetylu stanowi ważny półprodukt i rozpuszczalnik w wielu gałęziach przemysłu. Istnieje kilka metod syntezy tego związku, z których obecnie największe znaczenie mają oksydatywne karbonylowanie metanolu oraz transestryfikacja cyklicznych węglanów alkilenowych i metanolu. Przedstawiono przegląd literaturowy dotyczący syntezy węglanu dimetylu przez transestryfikację węglanu propylenu metanolem wobec czwartorzędowych soli oniowych i cieczy jonowych jako katalizatorów.

EN

A review, with 62 refs., of dimethyl carbonate (DMC) synthesis methods, along with their advantages and disadvantages. In particular, the process of transesterification of propylene carbonate with MeOH in the presence of quaternary ammonium salts and imidazolium ionic liquids as catalysts was presented. The use of homogeneous and heterogeneous catalysts were discussed, among which polymeric materials, MCM41, chitosan, activated C, silica gel and graphene oxide were used as supports.

2

Energy Valorization of Olive Mill Waste Cake – Extraction of Vegetable Oil and Transesterification

Mehdaoui Imane, Majbar Zineb, Hassani El Mokhtar Saoudi, Mahmoud Rachid, Atemni Ibrahim, Ben Abbou Mohamed, Taleb Mustapha, Rais Zakia

Journal of Ecological Engineering

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2023

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Vol. 24, nr 5

306--315

EN

The olive mill wastewater, effluents from the trituration of olives, are treated in most Mediterranean countries by natural evaporation. However, this method of treatment is a source of air and soil pollution by the generation of solid waste, called olive mill waste cake. This work focused on extracting of vegetable oil from this by-product for biodiesel production by transesterification. The extraction took place with a Soxhlet extractor, using hexane as solvent. The vegetable oil and biodiesel were characterized by measuring the physicochemical parameters that identify them according to AFNOR standards. The extraction results show that the oil yield is 21.28%. The oil obtained is characterized by density, water and ash content, acidity, saponification, peroxide and ester. The yield of the oil esterification reaction is 86.41% or about 185 Kg of biodiesel/ton of olive mill waste cake, and in terms of energy 2783.7 MJ or 2 GW.t-1. The biodiesel produced is comparable to petroleum diesel according to EN 14214, 2013.

3

Biodiesel Production of Palm Oil Mill Effluent by Using Hydrotalcite Catalyst

Agustina Tuty Emilia, Heraldy Eddy, Hadiah Fitri, Hasanudin, Arita Susila, Prakoso Tirto, Sari Tuti Indah, Suprapto Bhakti Yudho, Putra Muhammad Firdaus Kusuma, Ramadhani Dimas Luthfi

Journal of Ecological Engineering

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2022

|

Vol. 23, nr 6

172--181

EN

Biodiesel is currently preferred for consumption and has been widely used as a substitute for diesel. This study aimed to determine the effect of various methanol-to-oil ratios in the esterification process and also the effect of hydrotalcite catalyst weight on the transesterification product. The catalyst was characterized with SEM, XRD, FTIR, and TG-DTG-DTA. The esterification process was operated at various oil-to-methanol ratios, i.e., 1:12–1:36 and the transesterification was performed using several catalyst weights, 0.5%–2.5%. The results showed that the optimum conditions of esterification were at the 1:30 molar ratio of oil-to-methanol, which decreased the amount of acid number by 95.75%, while the optimum condition of transesterification was at 1.5% catalyst weight. The characteristics of biodiesel using 0.5–2% hydrotalcite catalyst (acid number, total glycerol, free glycerol, ester levels, viscosity, density, oxidation stability) have met the Indonesian biodiesel standard of SNI-04-7182-2012.

4

Processing and Performance of Blended Biodiesel Produced from Microalgae Pediastrum Boryanum

Chellappa Thiago, da Silva Raphael Eliedson, Filgueira Mário Sérgio Gomes, Rabelo Daniela Aisha Silva de Souza, Lira Isadora Patriota de Aguiar, Bremgartner Afra Raquel de Almeida, Bragato Marcos, Santos Dino Lincoln Figueirôa, Rosa José Guilherme da Silva Santa, Chellappa Naithirithi T., Sanábio Robson Guimarães, Nascimento Rubens M.

Rocznik Ochrona Środowiska

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2021

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Tom 23

243--262

EN

In this present study, biodiesel was synthesized as per ASTM method by using algae as a raw material, which in the environment is considered as being a harmful waste and of a nature that blooms in ponds, lakes and reservoirs. In order to improve fuel quality, the transesterification process was carried out in this study so as to remove fatty acids and thereafter, analyze several fuel parameters of the biodiesel were determined. The calorific value of the biodiesel and its specific gravity was 42660 kJ/kg and 0.803 g/cm3 respectively. The viscosity of the sample was found to be 1.99. The cetane number of diesel fuel ranged from 40 to 55 and for the biodiesel it was found to be 47. The flashpoint and firepoint of the sample was recorded as 80°C and 94°C respectively. The conclusion is that it is worthy to mention that this process does not require high-end technology; hence, it could be used in the energy generation process in remote areas and as an alternative resource, as well.

5

Biodiesel Production using Oil Extracted from Cooling Pond Wastewater with Esterification of Sulfonated Carbon Catalyst and Transesterification of Na2CO3 Catalyst

Kolakaningrum Chandra Fitri, Agustina Tuty Emilia, Hadiah Fitri

Journal of Ecological Engineering

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2021

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Vol. 22, nr 10

51--62

EN

While high production of palm oil improves the community economy, it has the potential to damage the environment because it produces the waste containing quite a lot of residual oil. The wastewater generated by this production process flows into the cooling pond before it is further processed in aerobic and anaerobic ponds. The residual oil contained in the cooling pond can be collected and used, e.g. as raw material for biodiesel production. This research aimed to produce biodiesel by utilizing the oil extracted from cooling pond wastewater through the esterification method with a sulfonated carbon catalyst and a transesterification method with the Na2CO3 catalyst. The sulfonated carbon catalyst was made from the palm kernel shells as a solid waste of the palm oil plant. In order to study the optimum amount of catalyst usage, the catalyst ratio was varied, i.e. 8–16% for the esterification process and 1–3% for the transesterification process. The reuse performance of sulfonated carbon catalysts was varied three times. On the basis of the research results, sulfonated carbon catalysts were proven to be effective as heterogeneous catalysts in the esterification process because they can reduce acid level to below 5 mg KOH/g oil. The sulfonated carbon catalyst ratio of 12% was the optimum ratio which can reduce the acid level to 4.62 mg KOH/g oil. The reuse of sulfonated carbon can reduce the acid level to 6.9 mg KOH/g oil at the first reuse. In the transesterification process, the optimum ratio of the Na2CO3 catalyst of 3% was found. The biodiesel produced has met the biodiesel characteristics of National Indonesian Standard (SNI of 7182:2015) with the saponification number of 197.18 mg KOH/g oil, free glycerol of 0.09%, FAME content of 96.79%, and density of 886 kg/m3.

6

Application of in-line ATR FTIR spectroscopy in the denvelopment of coating materials

Kędzierski Michał, Ofat-Kawalec Izabela, Bończa-Tomaszewski Zbigniew

Farby i Lakiery

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2019

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nr 3

6--14

EN

Selected examples of using in-line ATR FTIR technique to control the synthesis of coating materials and analyze the interactions of coating components and functional additives will be presented. React IR™ system (Mettler Toledo), composed of portable ATR FTR spectrometer, fiber conduit probe tipped with diamond sensor and software Processing the acquired spectroscopic data, was successfully applied for monitoring of real-time conversion of reactants during the addition of dicyclopentadiene (DCPD) and maleic acid, emulsion polymerization of octamethylcyclotetrasiloxane, synthesis of polyester resin for powder coatings by transesterification and study on the interaction of isophorone diisocyanate with hydrotalcite nanofiller.

PL

Zaprezentowane zostaną wybrane przykłady zastosowania techniki ATR FTIR in-line do kontroli syntezy materiałów powłokowych i analizy wzajemnego oddziaływania składników wyrobów lakierowych i dodatków funkcjonalnych. System React IR™ (Mettler Toledo), składający się z przenośnego spektrometru ATR FTIR, sondy światłowodowej zakończonej czujnikiem diamentowym i oprogramowania przetwarzającego uzyskane dane spektroskopowe, z powodzeniem zastosowano do monitorowania konwersji reagentów w czasie rzeczywistym podczas dodawania dicyklopentadienu (DCPD) i kwasu maleinowego, polimeryzacji emulsyjnej oktametylocyklotetrasiloksanu, syntezy żywicy poliestrowej do farb proszkowych przez transestryfikację i badania wzajemnego oddziaływania diizocyjanianu izoforonu z nanowypełniaczem w postaci hydrotalcytu.

7

Physicochemical properties of fuel compositions obtained from diesel fuel and different kinds of fatty raw material

Duda K., Piętak A.

Journal of KONES

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2018

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Vol. 25, No. 3

137--143

EN

Increased interest in development of alternative fuels used to power combustion engines is caused by excessive use of fuels obtained from mineral sources. Depletion of resources, political aspects as well as the negative impact on the environment are commonly discussed issues in relation to fossil fuels. On the other hand, biodegradability, lower toxic components emissions and interchangeability with mineral fuels are commonly described benefits related to biodiesel, interpreted as fatty acid methyl esters obtained from fatty raw material. Also the multiplicity of raw materials that can be used for production promotes popularization of the biodiesel. However the variety of raw materials can have significant impact on the number of physicochemical properties of alternative fuels due to the differences in molecular structures forming given type of raw material. The article presents analysis of properties of different types of biodiesel and its mixtures with diesel according to the outlines presented in the quality standards for mineral and alternative fuels. Alternative fuels were produced in the laboratory setup from swine, poultry, rape and sunflower fatty raw material. Such parameters as: density, kinematic viscosity, flash point, acid value, oxidation stability, cold filter plugging point, sulphur content, water content and total contamination were examined, based on the results, the quality of the biofuels was evaluated. Study confirms that biofuels derived from plant origin fatty raw material present favorable results in the aspect water content, total contamination, acid value and cold flow properties, thus biofuels derived from animal origin raw fatty material presents lower density and sulphur content.

8

Wpływ wybranych depresatorów na temperaturę zablokowania zimnego filtra dla estrów metylowych z procesów transestryfikacji odpadowych tłuszczów roślinnych i zwierzęcych

Marcinkowski D., Rukowicz B., Golimowski W., Czechlowski M., Krzaczek P., Piekarski W.

Przemysł Chemiczny

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2017

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T. 96, nr 9

1927--1930

PL

Zbadano wpływ wybranych depresatorów przeznaczonych do poprawy niskotemperaturowych właściwości biopaliw na jakość biodiesla otrzymywanego z surowców odpadowych. W wyniku transestryfikacji tłuszczów różnego pochodzenia uzyskano biopaliwa o zmiennych parametrach jakościowych. Stwierdzono, że zastosowanie wybranych depresatorów nie ma znacznego wpływu na temperaturę zablokowania zimnego filtra (CFPP) badanego biodiesla. Dodatkowo wykazano, że nie ma istnych różnic w CFPP dla estrów metylowych otrzymywanych z tłuszczów posmażalniczych i zwierzęcych.

EN

Three depressants were added (1–15% by mass) to 18 biofuels made by transesterification of frying and animal fats studied then for cold filter plugging points. The temps. decreased with increasing contents of the depressants in the range from -14°C to 18°C depending on the biofuel but the use of depressants did not have any significant effect on the biodiesels.

9

Wpływ ultradźwięków na produkty transestryfikacji olejów roślinnych

Grabowski P.

Przemysł Chemiczny

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2017

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T. 96, nr 4

752--755

PL

Zbadano wpływ ultradźwięków na produkty transestryfikacji olejów roślinnych. Sprawdzono zmianę takich właściwości fizykochemicznych, jak gęstość i lepkość, oraz możliwość tworzenia się pierwotnych i wtórnych produktów utlenienia, mających wpływ na stabilność oksydacyjną otrzymywanego biodiesla. Dodatkowo zbadano wpływ ultradźwięków na stężenie estrów metylowych w badanym produkcie. Stwierdzono, że zastosowanie ultradźwięków nie wpływa na gęstość, lepkość oraz skład biodiesla, wpływa jednak na pogorszenie stabilności oksydacyjnej, co wynika z powstawania pierwotnych i wtórnych produktów utleniania.

EN

Fatty acid Me ester was treated with ultrasounds at 40°C (energy input 20–100 Wh) and studied for oxidn. stability after 4 and 8 days. The anisidine values of the ester increased with increasing energy input. No substantial changes of the peroxide no., kinematic viscosity and d. were obsd.

10

Kinetics of Enantiomerically Enriched Synthesis of Solketal Esters Using Native and SBA-15 supported P. Fluorescens Lipase

Zniszczoł A., Szymańska K., Kocurek J., Bryjak J., Walczak K., Jarzębski A.

Chemical and Process Engineering

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2017

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Vol. 38, nr 2

209--215

EN

The studies showed that alkaline lipase from Pseudomonas fluorescens enables an irreversible transesterification of vinyl esters to give enantiomeric excess (eeR) of about 80% using vinyl butyrate as acyl donor and diisopropyl ether as a solvent, at partially optimized conditions. For the native lipase the process was adequately described by a five-parameter Ping-Pong Bi Bi model for both enantiomers plus expression accounting for the formation of enzyme-acyl donor complex, but for the same lipase supported on mesoporous materials of SBA-15-Oc type, R-product inhibition also had to be taken into account. The use of hydrophobic support increased by more than two-fold the rate of the S-solketal conversion but even more that of R-solketal. Thus the immobilization of lipase had very positive effect on the process kinetics but decreased its enantioselectivity.

11

The effect of the ultrasounds treatment on frying oils intended for biodiesel production

Ambrosewicz-Walacik M., Szostak P., Nitkiewicz S., Tańska M., Walacik M.

Journal of KONES

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2016

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Vol. 23, No. 3

19--24

EN

The aim of the study was to determine the ultrasounds treatment of frying oil on their properties important in order to biodiesel production. The research material was a frying oil, which prior to transesterification oil was treated with ultrasounds (37 kHz) during 15, 30 and 60 min. In next step, prepared samples were analysed in terms of fatty acid composition, acid value, FFA % and then subjected to alkali transesterification process. After producing methyl esters the yield of biodiesel was analysed with thin liquid chromatography technique (TLC), and then samples were characterized in terms of viscosity in 40 °C, density at 15 °C, acid value, sulphur content and flash point. The results showed that an ultrasonic treatment had a little impact on the fatty acid composition of the test samples. The yield of biodiesel was the higher the longer time of ultrasounds treatment were used. One the other hand, determined with thin liquid chromatography technique yield of biodiesel was the higher the longer time of ultrasounds treatment were used. What is more, the ultrasounds treatment of oil before transesterification process had no impact on viscosity, density and acid value of these samples, while flash point values and sulphur content were changed.

12

Transestryfikacja enzymatyczna oleju słonecznikowego z wykorzystaniem promieniowania mikrofalowego

Narowska B., Kułażyński M., Łukaszewicz M.

Przemysł Chemiczny

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2015

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T. 94, nr 8

1424-1427

PL

Olej słonecznikowy poddano reakcji transestryfikacji z udziałem metanolu oraz biokatalizatora enzymatycznego (Lipaza B z Candida antarctica immobilizowana na Immobead 150) lub homogenicznego katalizatora zasadowego (KOH). W reakcji transestryfikacji stosunek molowy metanolu do oleju wynosił odpowiednio 4:1 i 6:1. Proces prowadzono w układzie tradycyjnego ogrzewania oraz w układzie reaktora przepływowego z ogrzewaniem mikrofalowym. Ogrzewanie energią mikrofalową znacząco skraca czas reakcji przy jednoczesnym wzroście jej wydajności.

EN

Sunflower oil was transesterified with MeOH to biodiesel on homogenous KOH catalyst or on an enzymatic catalyst (lipase B from Candida antarctica immobilized on Immobead 150) in microwave and conventionally heated reactors. The microwave irradiation resulted in an acceleration of the reaction and increasing the product yield.

13

Carbon-based acid catalyst from waste seed shells: preparation and characterization

Wang L. H., Liu H., Li L.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 4

37--41

EN

A carbon-based solid acid catalyst was prepared by the sulfonation of carbonized seed shells of Jatropha curcas (J. curcas L.). The structure of amorphous carbon consisting of polycyclic aromatic carbon sheets attached a high density of acidic SO3H groups (2.0 mmol · g−1) was identified with scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The performance of the solid acid catalyst was evaluated for biodiesel production in the esterification of oleic acid with methanol. 95.7% yield of biodiesel was obtained after 2 h reaction and the conversions with reused catalyst varied in the range of 95.7% to 95.1%, showing better activity and stability than commercial catalyst amberlyst-46. It was also observed that the prepared catalyst showed enhanced activity in the transesterification of triolein with methanol when compared with other solid acid catalysts. A synergistic effect results from the high density of SO3H groups and the good access of reactants to the acidic sites can be used to explain the excellent catalytic activity, as well as the strong affinity between the hydrophilic reactants and the neutral OH groups bonded to the polycyclic aromatic carbon rings.

14

Layered double hydroxides as transesterificationcatalysts and nanofillers for polyester resin

Kędzierski M., Bończa-Tomaszewski Z., Jaworska G., Niska A.

Polimery

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2015

|

T. 60, nr 3

160--166

EN

Saturated polyester resins were prepared by reaction of dimethylterephthalate with alkylene glycols in the presence of layered doublehydroxides (hydrotalcites, HT). The effect of HT composition (cation and aniontypes) on the rate and progress of transesterification was investigated. It was found that zinc-aluminum HT intercalated with anionic form of aminolauric acid[HT(ZnAl)ALA] efficiently catalyzes transesterification process, increasing therate of reaction or lowering its temperature when compared to the reaction with use of conventional organic tin catalyst. The polyester resin obtained in this way is transparent, which along with X-ray diffraction data indicates the delamination of clay layers and formation of nanocomposite. The limitation of using ALA-intercalated HT as an additive for polyesters used in coatings is coloration of the resin with an increase of the reaction temperature above 180°C. Colorless polyester was obtained using more thermally stable hydrotalciteintercalated with ethylenediaminetetraacetic acid, however, at the expense of significantly longer reaction time. Using HT(ZnAl)ALA catalyst a two-step synthesis of carboxyl polyester resin was performed and the obtained product was used as a component of powder coating formulation.

PL

Przeprowadzono syntezę nasyconych żywic poliestrowych w reakcji tereftalanu dimetylowego z glikolami alkilenowymi, w obecności warstwowego podwójnego wodorotlenku typu hydrotalkitu (HT). Analizowano wpływ składu HT na szybkość i wydajność transestryfikacji. Najlepsze wyniki (zwiększenie szybkości reakcji lub obniżenie średniej temperatury procesu w porównaniu z szybkością i temperaturą reakcji prowadzonej w obecności tradycyjnego katalizatora organocynowego) uzyskano z zastosowaniem hydrotalkitu interkalowanego kwasem aminolaurynowym (ALA). Otrzymane w taki sposób żywice były transparentne, co w połączeniu z zanikiem refleksów hydrotalkitu w widmie XRD produktu transestryfikacji może świadczyć o utworzeniu się delaminowanego nanokompozytu. Wykorzystanie HT interkalowanego ALA w żywicach poliestrowych stosowanych do powłok jest ograniczone ze względu na zabarwienie pojawiające się w temperaturze powyżej 180 °C. W reakcji prowadzonej z udziałem bardziej stabilnego termicznie hydrotalkitu modyfikowanego kwasem etylenodiaminotetraoctowym otrzymano bezbarwny poliester, jednak kosztem znacznego wydłużenia czasu reakcji. Katalizator HT(ZnAl)ALA zastosowano w dwustopniowej syntezie poliestru o łańcuchu zakończonym grupami karboksylowymi, który następnie użyto w charakterze składnika proszkowej kompozycji powłokowej.

15

Zastosowanie cieczy jonowych i katalizatorów stałych w syntezie biokomponentów paliwowych

Oleksik J., Krasodomski W.

Nafta-Gaz

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2015

|

R. 71, nr 4

256--265

PL

W artykule dokonano przeglądu literatury dotyczącej możliwości wykorzystania nowoczesnych katalizatorów w procesach estryfikacji i transestryfikacji olejów roślinnych prowadzących do otrzymania biokomponentów paliwowych. W opracowaniu szczególną uwagę poświęcono dwóm grupom katalizatorów, to jest: jonitom reprezentującym katalizatory stałe oraz cieczom jonowym.

EN

This article presents a review of literature concerning the possibility of using modern catalysts in the process of esterification and transesterification of vegetable oils, thus leading to obtaining biocomponents. This paper specifically focuses on two groups of catalysts: ionites representing solid catalysts and ionic liquids.

16

Produkcja biodiesla w procesie transestryfikacji wyższych kwasów tłuszczowych zawartych w olejach roślinnych

Sadek R., Chałupka K., Bawolak K., Dźwigaj S.

Eliksir

|

2015

|

nr 1

23--25

17

Investigation of the chemical composition, characterization and determination of energy content for renewable energy source (biodiesel) produced from non-edible Ethiopian seeds’ particularly castor seed (Ricinus communis) using homogeneous catalysis

Hiwot T.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 18

63--74

EN

Biodiesel is a clean, renewable, biodegradable, environmentally benign, energy efficient and diesel substituent fuel used in diesel engine. It provides a feasible solution to the twin crises of fossil fuel depletion and environmental pollution. It is produced from renewable sources such as vegetable oils or animal fats by trans-esterification. Although this fuel has gained worldwide recognition for many years, it is not being widely commercialized like petroleum diesel in the world, not widely produced and used especially in our country Ethiopia. Analysis of fatty acid methyl ester composition of the biodiesel produced from castor oil was done with the help of GC-MS and 8 fatty acid methyl esters were identified. Acid and base catalyzed methods were used in the synthesis of biodiesel from castor seed oil. In addition to this the variables that affect the amount of methyl ester yield were determined and an optimum of 96.7 % fatty acid methyl ester (FAME) conversion was obtained at a methanol to oil molar ratio of 6:1, 1.0 % mass NaOH, 65 °C reaction temperature and 3 hour reaction time. The energy content of the oil and biodiesel were 39 MJ/Kg and 40.7 MJ/ Kg respectively which is determined by bomb calorimeter. Other physicochemical properties of the biodiesel were determined and all these lie within the ASTM and EN biodiesel standards except kinematic viscosity. Therefore, castor seed oil methyl ester could be used as an alternative energy resource in diesel engine by blending with petroleum diesel.

18

Investigation of chemical composition, characterization and determination of biodiesel content for the oil extracted from waste coffee residue of different varieties of coffee beans grown in yirgachefie, kocherea and yirgalem using homogeneous catalysis and comparing it with fossil fuels

Hiwot T.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 20, iss. 1

88--89

EN

Due to rapid population growth and development in the world there is high energy demand, energy consumption, sharp decline in petro fuels reserves, and greater environmental problems, as a result of using petroleum diesel constrained mankind to investigate newer and renewable feed stocks for liquid transportation fuels from vegetable oils by transesterification reaction. In this study oil of waste coffee residue of yirgachefie, yirgalem and kocherea (chellelleqtu) weredas were selected as potential raw from indigenous species for biodiesel production. Oil was extracted using n-hexane as a solvent from waste coffee residue of yirga chefie, yirgalem and kocherea weredas. The oil contents for yirgachefie, yirgalem and kocherea were 16.67% w/w, 19.7 % w/w and 16.9% w/w respectively. Transesterification were carried out for all oils using methanol in the presence of acidic and basic catalysts to produce biodiesel. The fatty acid methyl esters in the biodiesel prepared from the oil extracted from three waste coffee residues were analyzed by FTIR and GC-MS. Based on GC-MS analysis their chemical compositions were 37.7 wt. % methyl palmitate (C16:0), 41 wt. % methyl linoleate (C18:2), 13.5 wt. % methyl oleate (C18:1) and 8.5 wt. % methyl stearate (C18:0) for yirgachefie, 35.90 wt.% methyl palmitate (C16:0), 38.28 wt. % methyl linoleate (C18:2), 16.42 wt. % methyl oleate (C18:1) and 9.40 wt.% methyl stearate (C18:0) for kocherea and 26.62 wt. % methyl palmitate (C16:0), 35.18 wt.% methyl linoleate (C18:2), 19.72 wt. % methyl oleate (C18:1) and 18.48 wt.% methyl stearate (C18:0) for yirgalem. In addition to this the variables that affect the amount of methyl ester yield were determined and an optimum of 94.7 %, 95.84 and 94.56 fatty acid methyl ester (FAME) conversion were obtained at a methanol to oil molar ratio of 6:1, 1.0 % mass NaOH, 65 °C reaction temperature and 3 hour reaction time for yirgachefie, yirgalem and kochera respectively. The energy content of the oil and biodiesel were 38, 36.2, 37 MJ/Kg and 38.68, 38, 41 MJ/ Kg for yirgachefie, yirgalem and kochera respectively which is determined by bomb calorimeter. Other physicochemical properties of the biodiesel were determined and all these lie within the ASTM and EN biodiesel standards except acidic value. Therefore, coffee seed oil methyl ester could be used as an alternative energy resource in diesel engine.

19

Enancjoselektywna enzymatyczna desymetryzacja katalizowana lipazami. Część 1, Związki prochiralne

Kołodziejska R., Karczmarska-Wódzka A., Tafelska-Kaczmarek A., Studzińska R., Dramiński M.

Wiadomości Chemiczne

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2013

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[Z] 67, 7-8

751--772

EN

In the enzymatic asymmetric synthesis, the enzyme allows the desymmetrization of achiral compounds resulting in chiral compounds of high optical purity. Therefore, this type of biotransformation is known as enantioselective enzymatic desymmetrization (EED) [1–11]. This method is related to the generation of an asymmetry (loss of symmetry elements) in prochiral molecules (most often an sp3 or sp2 hybridized carbon atom), in meso synthones, and centrosymmetric compounds. An achiral center of the tetrahedral system is defined as a prochiral one if it becomes chiral as a result of one of the two substituents replacement which, when separated from the particles, are indistinguishable (Scheme 1, 2) [1–4, 9, 12]. Asymmetric synthesis is enantioselective when one of the enantiotopic groups or faces of an optically inactive compound is biotransformed faster than the other (Scheme 3–5) [1, 10, 11, 13–15]. Lipases are enzymes of highest importance in stereoselective organic synthesis, mainly due to their exceptionally broad substrate tolerance, stability, activity in unphysiological systems, and relatively low price [9, 14]. The mechanism of enzymatic hydrolysis catalysed by hydrolases is similar to that observed in the chemical hydrolysis with the use of base. The selectivity of enzymatic catalysis depends on the substrate orientation in the enzyme active site (Scheme 6, 7) [25–29]. Lipases were successfully used for the desymmetrization of different prochiral diesters, alcohols and amines. Most lipases preferentially convert the same prochiral groups in the above mentioned types of reaction. This allows the preparation of the both enantiomers of the product in high chemical and optical yield (Scheme 9–13) [9, 13, 32–56].

20

Enancjoselektywna enzymatyczna desymetryzacja katalizowana lipazami. Część II, Optymalizacja warunków reakcji. Związki mezo

Karczmarska-Wódzka A., Kołodziejska R., Tafelska-Kaczmarek A., Przybyła T., Dramiński M.

Wiadomości Chemiczne

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2013

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[Z] 67, 9-10

819--841

EN

In the enzymatic asymmetric synthesis, the enzyme allows the desymmetrization of achiral compounds resulting in chiral compounds of high optical purity. Meso compounds (bearing a plane of symmetry) are very important group of compounds used in EEDs (Scheme 1) [1–4]. Similarly to prochiral compounds, selective acylation or hydrolysis of meso substrates leads to optically active products. Most lipases preferentially convert the same enantiomers in the above mentioned types of reaction. This allows the preparation of the both enantiomers of the product in high chemical and optical yield (Scheme 3–20) [35–58]. An effective enzymatic catalysis should be performed under conditions optimal for a biocatalyst performance. Hence, it is essential to select an appropriate reaction medium, the pH, and temperature [6–34]. Optimization of the reaction conditions in terms of an appropriate solvent selection is effective and most frequently the simplest way to modify the enzyme selectivity. One of the most important criteria for the solvent selection is its nature [25]. The enzyme selectivity is conditioned by its conformational rigidity, which increases in more hydrophobic medium (typical hydrophobic solvents, scCO2). A hydrophobic solvent decreases biocatalyst lability, which does not allow the connection between the structurally mismatched substrate and the active side of an enzyme [10, 26–31]. Ionic liquids are a separate group of solvents which, despite their high hydrophobicity (logP << 0) and polarity, can constitute an ideal medium for the biotransformation reactions [18–23].