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U ovoj disertaciji ispitivana je sinteza metil estara masnih kiselina (MEMK), odnosno biodizela u reakciji metanolize triglicerida (TG) u prisustvu čvrstog katalizatora. Sinteza katalizatora izvršena je mehanohemijskim putem polazeći od CaO i ZnO prahova uz dodatak vode, kako bi se dobio prekursor CaZn2(OH)6·2H2O, koji se ţarenjem na 700 °C prevodi u smešu oksida CaO∙ZnO. Nakon detaljne karakterizacije, CaO∙ZnO katalizator korišćen je u reakciji metanolize rafinisanog suncokretovog i korišćenog biljnog ulja (KBU) koja je izvedena u šarţnim uslovima. U cilju odreĎivanja parametara koji u potpunosti definišu brzinu metanolize i ukazuju na osnovne otpore od kojih ona zavisi, analiziran je uticaj temperature, molarnog odnosa metanol:ulje, mase katalizatora i intenziteta mešanja na brzinu procesa. UtvrĎeno je da brzina procesa zavisi od otpora prenosu mase TG do površine katalizatora i otpora hemijskoj reakciji na površini katalizatora, koji su definisani kao recipročna vrednost ukupnog zapreminskog koeficijenta prenosa mase, , i konstante brzine reakcije pseudo prvog reda, . Ovi kinetički parametri odreĎuju vrednost prividne konstante brzine koja se menja sa napredovanjem procesa metanolize, odnosno sa promenom stepena konverzije TG. Brzina procesa je na taj način opisana kinetičkim modelom nepovratne reakcije prvog reda sa promenljivom prividnom konstantom brzine koja uzima u obzir i prenos mase TG i brzinu hemijske reakcije izmeĎu TG i metanola. UtvrĎeno je da ukupan zapreminski koeficijent prenosa mase, , zavisi od specifične meĎufazne površine, kao i da se moţe predstaviti kao funkcija stepena konverzije TG. Ova pretpostavka se bazira na uočenom efektu da se dostizanjem odreĎene kritične konverzije TG nakon stvaranja prvih količina monoglicerida (MG), diglicerida (DG) i MEMK, brzina prenosa mase znatnije uvećava i postaje veća od brzine hemijske reakcije na površini katalizatora. Tada reakcija na površini katalizatora počinje da kontroliše brzinu ukupnog procesa..., The synthesis of fatty acid methyl esters (FAME), i.e. biodiesel, in the methanolysis of triglycerides (TG) in the presence of solid catalyst was studied. Heterogeneous catalyst was synthesized by mechanochemical treatment of CaO and ZnO powder mixture with the addition of water required for the formation of corresponding mixed hydroxides, CaZn2(OH)6·2H2O, followed by calcination at 700 °C in air to obtain CaO∙ZnO composite powder. After detailed characterization CaO∙ZnO catalyst was used in methanolysis of refined sunflower as well as used vegetable oil (UVO) in the batch conditions. Influence of temperature, agitation speed, catalyst amount and methanol to oil molar ratio on the rate of reaction was analyzed in order to determine parameters that completely define the rate of methanolysis and indicate the basic resistances on which it depends. It was revealed that the rate of the process depends on the two resistances – mass transfer of triglycerides to the catalyst surface and chemical reaction on the catalyst surface, which are defined as reciprocal value of , the overall triglyceride volumetric mass transfer coefficient and , the effective pseudo-first order reaction rate constant. These kinetic parameters actually determine the value of the apparent reaction rate constant, , which changes with the progression of the methanolysis process, i.e. with the change of triglyceride conversion. The rate of the process is thus described with the simple kinetic model of irreversible pseudo-first order reaction with the variable apparent rate constant, which takes into account both the triglycerides mass transfer and chemical reaction between TG and methanol. The overall volumetric mass transfer coefficient, , was found to depend on interfacial area between the oil and methanol, and can be presented as the function of TG conversion. This assumption is based on the observed effect that when critical conversion of TG is achieved, after formation of small amounts of MG, DG an

The synthesis of fatty acid methyl esters (FAME), i.e. biodiesel, in the methanolysis of triglycerides (TG) in the presence of solid catalyst was studied. Heterogeneous catalyst was synthesized by mechanochemical treatment of CaO and ZnO powder mixture with the addition of water required for the formation of corresponding mixed hydroxides, CaZn2(OH)6·2H2O, followed by calcination at 700 °C in air to obtain CaO∙ZnO composite powder. After detailed characterization CaO∙ZnO catalyst was used in methanolysis of refined sunflower as well as used vegetable oil (UVO) in the batch conditions. Influence of temperature, agitation speed, catalyst amount and methanol to oil molar ratio on the rate of reaction was analyzed in order to determine parameters that completely define the rate of methanolysis and indicate the basic resistances on which it depends. It was revealed that the rate of the process depends on the two resistances – mass transfer of triglycerides to the catalyst surface and chemical reaction on the catalyst surface, which are defined as reciprocal value of , the overall triglyceride volumetric mass transfer coefficient and , the effective pseudo-first order reaction rate constant. These kinetic parameters actually determine the value of the apparent reaction rate constant, , which changes with the progression of the methanolysis process, i.e. with the change of triglyceride conversion. The rate of the process is thus described with the simple kinetic model of irreversible pseudo-first order reaction with the variable apparent rate constant, which takes into account both the triglycerides mass transfer and chemical reaction between TG and methanol. The overall volumetric mass transfer coefficient, , was found to depend on interfacial area between the oil and methanol, and can be presented as the function of TG conversion. This assumption is based on the observed effect that when critical conversion of TG is achieved, after formation of small amounts of MG, DG an, U ovoj disertaciji ispitivana je sinteza metil estara masnih kiselina (MEMK), odnosno biodizela u reakciji metanolize triglicerida (TG) u prisustvu čvrstog katalizatora. Sinteza katalizatora izvršena je mehanohemijskim putem polazeći od CaO i ZnO prahova uz dodatak vode, kako bi se dobio prekursor CaZn2(OH)6·2H2O, koji se ţarenjem na 700 °C prevodi u smešu oksida CaO∙ZnO. Nakon detaljne karakterizacije, CaO∙ZnO katalizator korišćen je u reakciji metanolize rafinisanog suncokretovog i korišćenog biljnog ulja (KBU) koja je izvedena u šarţnim uslovima. U cilju odreĎivanja parametara koji u potpunosti definišu brzinu metanolize i ukazuju na osnovne otpore od kojih ona zavisi, analiziran je uticaj temperature, molarnog odnosa metanol:ulje, mase katalizatora i intenziteta mešanja na brzinu procesa. UtvrĎeno je da brzina procesa zavisi od otpora prenosu mase TG do površine katalizatora i otpora hemijskoj reakciji na površini katalizatora, koji su definisani kao recipročna vrednost ukupnog zapreminskog koeficijenta prenosa mase, , i konstante brzine reakcije pseudo prvog reda, . Ovi kinetički parametri odreĎuju vrednost prividne konstante brzine koja se menja sa napredovanjem procesa metanolize, odnosno sa promenom stepena konverzije TG. Brzina procesa je na taj način opisana kinetičkim modelom nepovratne reakcije prvog reda sa promenljivom prividnom konstantom brzine koja uzima u obzir i prenos mase TG i brzinu hemijske reakcije izmeĎu TG i metanola. UtvrĎeno je da ukupan zapreminski koeficijent prenosa mase, , zavisi od specifične meĎufazne površine, kao i da se moţe predstaviti kao funkcija stepena konverzije TG. Ova pretpostavka se bazira na uočenom efektu da se dostizanjem odreĎene kritične konverzije TG nakon stvaranja prvih količina monoglicerida (MG), diglicerida (DG) i MEMK, brzina prenosa mase znatnije uvećava i postaje veća od brzine hemijske reakcije na površini katalizatora. Tada reakcija na površini katalizatora počinje da kontroliše brzinu ukupnog procesa...

The goal of this study was to prepare a CaO·ZnO catalyst containing a small amount of K2CO3 and analyze its activity for biodiesel synthesis. The catalyst was prepared using the following procedure: CaO and ZnO (mole ratio of 1:2), water and K2CO3 (in various amounts) were mechanochemically treated and after milling heated at 700°C in air atmosphere for obtaining mixed CaO·ZnO/xK2CO3 oxides (x = 0, 1, 2 and 4 mol of K2CO3 per 10 mol of CaO). All the samples were characterized by X-ray diffraction (XRD), inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), scanning electron microscopy/ energy-dispersive spectroscopy (SEM/EDS), particle size laser diffraction (PSLD) distribution, solubility measurement of Ca, Zn and K ions in methanol as well as by determination of their alkalinity (Hammett indicator method). Prepared CaO·ZnO/xK2CO3 composite powders were tested as catalysts for methanolysis of sunflower oil at 70 °C using mole ratio of sunflower oil to methanol of 1:10 and with 2 mass% of catalyst based on oil weight. The presence of K2CO3 in prepared samples was found to increase the activity of catalyst, and that such effect is caused by homogeneous-heterogeneous catalysis of biodiesel synthesis., Cilj ovih istraživanja bio je da se pripremi CaO·ZnO katalizator koji sadrži malu količinu K2CO3 i analizira njegova aktivnost u sintezi biodizela. Katalizator je pripremljen prema sledećoj proceduri: CaO i ZnO (molski odnos 1:2), voda i K2CO3 (u različitoj količini) su tretirani mehanohemijski i nakon mlevenja zagrevani na 700 °C u atmosferi vazduha da bi se dobila smeša oksida CaO·ZnO/xK2CO3 (x = 0, 1, 2 i 4 mol K2CO3 na 10 mol CaO). Karakterizacija pripremljenih katalizatora izvršena je metodama rendgenske difrakcije (XRD), indukovane kuplovane plazme (ICP), spektroskopije fotoelektrona dobijenih X-zracima (XPS), termogravimetrijske analize (TGA), infracrvene spektroskopije (FTIR), skenirajuće elektronske mikroskopije i energetske disperzione spektroskopije (SEM/EDS), raspodele veličine čestica (PSLD), merenjem rastvorljivosti katalizatora odnosno Ca, Zn i K jona u metanolu, kao i određivanjem njihove baznosti (metodom Hametovih indikatora). Pripremljeni CaO·ZnO/xK2CO3 kompozitni prahovi testirani su kao katalizatori u reakciji metanolize suncokretovog ulja na 70 °C, pri molarnom odnosu suncokretovog ulja i metanola od 1:10 i sa 2 mas.% katalizatora u odnosu na masu ulja. Pokazano je da prisustvo K2CO3 u pripremljenim uzorcima povećava aktivnost katalizatora i da je takav efekat posledica homogeno-heterogene katalize u sintezi biodizela.

The kinetic model originally developed for quicklime-catalyzed methanolysis of sunflower oil was tested for another three calcium-based catalysts, namely, neat CaO, Ca(OH)2, and CaO·ZnO. This model includes the changing reaction mechanism and the triacylglycerol (TAG) mass transfer. The applicability and generalization capability of this model for heterogeneous methanolysis reaction catalyzed by calcium-based catalysts was evaluated. As indicated by the high coefficient of determination and the relatively small mean relative percentage deviation, the model was a reliable predictor of the time variation of TAG conversion degree in the sunflower oil methanolysis over all four calcium-based catalysts within the ranges of the reaction conditions applied. This model is recommended in general for describing the kinetics of sunflower oil methanolysis over calcium-based catalysts.The kinetic model originally developed for quicklime-catalyzed methanolysis of sunflower oil was tested for another three calcium-based catalysts, namely, neat CaO, Ca(OH)2, and CaO·ZnO. This model includes the changing reaction mechanism and the triacylglycerol (TAG) mass transfer. The applicability and generalization capability of this model for heterogeneous methanolysis reaction catalyzed by calcium-based catalysts was evaluated. As indicated by the high coefficient of determination and the relatively small mean relative percentage deviation, the model was a reliable predictor of the time variation of TAG conversion degree in the sunflower oil methanolysis over all four calcium-based catalysts within the ranges of the reaction conditions applied. This model is recommended in general for describing the kinetics of sunflower oil methanolysis over calcium-based catalysts.

A heterogeneous catalyst, ZnO supported on alumina/silica, was synthesized by the sol-gel method. The prepared catalysts were employed for methanolysis of sunflower oil. Effects of various supports as well as calcination temperature were evaluated following the kinetics of the reaction. Simple first-order irreversible and reversible reaction models were applied to determine the reaction rate constant. The results proved that under optimized conditions the catalyst exhibited good activity in the methanolysis of sunflower oil and the kinetics of the methanolysis process could be expressed by the first-order reversible reaction model. For other catalysts with lower activity, the first-order irreversible reaction model could be successfully applied to describe well the process kinetics.

The kinetics of heterogeneous methanolysis of sunflower oil was studied at 60 °C using mechanochemically synthesized CaO·ZnO as catalyst. The influence of agitation speed, catalyst amount, and methanol-to-oil molar ratio on the rate of reaction was analyzed. The rate of the process depends on the two resistances - mass transfer of triglycerides to the catalyst surface and chemical reaction on the catalyst surface, which are defined as the values of the overall triglyceride volumetric mass transfer coefficient, kmt,TG, and the effective pseudo first-order reaction rate constant, k, respectively. These kinetic parameters actually determine the value of the apparent reaction rate constant, kapp, the time dependence of which is defined by the change of triglyceride (TG) conversion. A kinetic model is proposed and the model parameters are determined., Kinetika heterogene metanolize suncokretovog ulja je ispitivana na 60 °C korišćenjem CaO·ZnO katalizatora koji je sintetizovan mehanohemijskim putem. Analiziran je uticaj intenziteta mešanja, mase korišćenog katalizatora u sintezi i različitog molskog odnosa metanola i ulja na brzinu metanolize. Brzina procesa metanolize zavisi od dva otpora - otpora prenosu mase triglicerida do površine katalizatora i otpora brzini hemijske reakcije na površini katalizatora. Oba otpora određuju vrednost ukupnog zapreminskog koeficijenta prenosa mase triglicerida, kmt,TG, odnosno efektivne vrednosti konstante brzine hemijske reakcije pseudo-prvog reda, k. Ovi kinetički parametri određuju vrednost prividne konstante brzine procesa metanolize, kapp, koja se menja sa vremenom u zavisnosti od ostvareneog stepena konverzije triglicerida (TG). Predložen je odgovarajući model kojim je moguće definisati brzinu metanolize i određeni su odgovarajući parametri ovog modela.

Cilj ove doktorske disertacije je postavljanje matematičkog modela složenog trofaznog reakcionog sistem za epoksidovanje sojinog ulja in situ formiranom persirćetnom kiselinom iz sirćetne kiseline i vodonik peroksida u prisustvu jonoizmenjivačke smole kao katalizatora. Model uzima u obzir koncentracije reaktanata i produkata u vodenoj i uljnoj fazi. Pored osnovnih reakcija stvaranja persirćetne kiseline i epoksida, model obuhvata i sporednu reakciju otvaranja epoksi prstena sa sirćetnom kiselinom. Za modelovanje reakcije formiranja persirćetne kiseline na površini katalizatora primenjeni su Langmuir-Hinshelwood- Hougen-Watson i Rideal-Eley postulati. Postavljeni trofazni model predstavlja sistem običnih diferencijalnih jednačina prvog reda koji opisuje promenu broja molova komponenata i funkcionalnih grupa sa vremenom izvođenja procesa epoksidovanja, i sadrži više parametara razvrstanih na kinetičke, termodinamičke i parametre koji se odnose na prenos mase. Parametri modela zavise od uslova izvođenja epoksidovanja i to svi od temperature, a neki i od sastava i inteziteta mešanja. Za konstantu hemijske ravnoteže reakcije nastajanja persirćetne kiseline je izvedena semiteorijska zavisnost od temperature koja daje vrednosti istog reda veličine i istog smera promene sa temperaturom kao i većina podataka objavljenih u literaturi. Za izračunavanje koeficijenta raspodele sirćetne kiseline između uljne i vodene faze potrebno je odrediti zavisnost konstante fazne ravnoteže tečno-tečno sirćetne kiseline od sastava i temperature. Utvrđeno je da je UNIFAC model grupnih doprinosa za koeficijente aktivnosti nepogodan za predskazivanje ravnoteže tečno-tečno. Eksperimentalni podaci za ovu konstantu ravnoteže su uspešno korelisani UNIQUAC modelom za koeficijente aktivnosti. Parametri reparametrizovane Arrheniusove zavisnosti konstanti brzina reakcija i konstanti sorpcije učesnika reakcije stvaranja persirćetne kiseline od temperature određeni su simultano sa parametrima koji se odno, The objective of this doctoral thesis was development of mathematical model for complex three-phase reaction system for soybean oil epoxidation with peracetic acid formed in situ from acetic acid and hydrogen peroxide in a presence of an ion exchange resin as catalyst. The local concentrations of components in water and oil phases were introduced into the model. In addition to reactions of the peracetic acid and epoxy compound formation, model considers the side reaction of epoxy ring cleavage with acetic acid. Approximate modeling of peracetic acid formation was based on Langmuir-Hinshelwood-Hougen- Watson and Rideal-Eley postulates. Established threephase model is a system of ordinary first order differential equations which describes change of components and functional groups amounts with reaction time. Besides kinetic parameters, model comprises the thermodynamic ones as well as parameters of mass transfer between the oil and water phase. All model parameters are dependent on temperature and some additionally on composition and intensity of stirring. A semitheoretical temperature dependency of chemical equilibrium constant for peracetic acid formation was established. The order of magnitude and temperature trend of the calculated chemical equilibrium constant are in agreement with the most data given in a literature. For calculation of partition coefficient for acetic acid between oil and water phase, temperature and composition dependency of liquid-liquid equilibrium constant for acetic acid is necessary. It was found that UNIFAC model of group contribution was non-applicable for the prediction of the equilibrium constant. The experimental data for the equilibrium constant were, however, successfully fitted by UNIQUAC model. Temperature dependencies of the reaction rate constants and sorption constants of reactants and products in peracetic acid formation reaction are expressed by reparameterized Arrhenius equation. The parameters of such equation were determin

In this study, the synthesis of biodiesel or fatty acid methyl esters (FAME) from sunflower oil and methanol using CaO center dot ZnO catalyst was investigated. Catalyst was synthesized by ball milling of Ca(OH)(2) and ZnO powder mixture with the addition of water (BMH), as well as solely by ball milling of mentioned powders (BM) and subsequent calcination at 700 degrees C in air atmosphere. For comparison, the CaO center dot ZnO mixed oxide was also prepared using usual coprecipitation procedure (CP) followed by calcination at 700 degrees C of the formed calcium zinc hydroxide hydrate. The BMH, BM and CP catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), particle size distribution measurement and scanning electron microscopy (SEM and SEM-EDS). In addition, specific surface area (BET), solubility in methanol at 60 degrees C and alkalinity (Hammett indicator method) were also determined. The activity of BMH, BM and CP catalysts for biodiesel synthesis were tested at 60 degrees C and 1 bar, using molar ratio of sunflower oil to methanol of 1:10 and with 2 wt% of catalyst based on oil weight.

Supercritical CO2 extraction was studied using dried leaves of Mentha, originated from the northern part of Libya. Leaves were milled and sieved to obtain different average particles (d(p) = 0.25 - 0.80 mm). They were treated with supercritical CO2 at 313 K and 10 MPa in order to isolate essential oil. The new approach of supercritical extraction modelling on the basis of proposed "pseudo kinetic model" (PKM) was investigated and compared to most applied in literature Sovova's model. The main focus of these investigation was to determine the influence of particle size on extractions yield and to determine optimal methodology for determination parameters of PKM. Achieved results showed good agreement between both models and experimental results and good prospects for further usage of PKM.

The transesterification of triglycerides (vegetable oil) with methanol using CaO·ZnO mixed oxides catalyst were conducted to produce Fatty Acid Methyl Esters (FAME), i.e. biodiesel. The catalysts were used in the methanolysis of sunflower oil, at 60°C and 1 bar, using molar ratio of sunflower oil to methanol of 1:10 and with 2 wt % of catalyst based on oil weight. All catalysts displayed good activity in the methanolysis of sunflower oil, with the yield of FAME gt 90% after 4 hr of reaction. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES (Prague, Czech Republic 8/25-29/2012).

The transesterification of triglycerides (vegetable oil) with methanol using CaO·ZnO mixed oxides catalyst were conducted to produce FAME (Fatty Acid Methyl Esters, i.e. biodiesel). Catalyst was synthesized by ball milling of CaO and ZnO powder mixture (using molar ratio of Ca and Zn of 1:2 and 1:4) with the addition of water, as well as solely by ball milling (molar ratio of 1:2) of mentioned powders and subsequent. After ball milling prepared mixtures were calcinatied at 700 oC in air atmosphere. The samples of formed catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The particle size distribution as well as the base strength using Hammett indicator was determined, too. CaO.ZnO catalysts were used in the methanolysis of sunflower oil, at 60 oC and 1 bar, using molar ratio of sunflower oil to methanol of 1:10 and with 2 wt% of catalyst based on oil weight. All catalysts exhibited good activity in the methanolysis of sunflower oil, with the yield of FAME above 90% after 4 hours of reaction.

A difficulty of biodiesel synthesis based on alkaline catalysts obviously exists if free fatty acids (FFAs) content in vegetable oil is above 0.5 wt.%. In this study, the ferric sulfate supported on silica (Fe-2(SO4)(3)/SiO2) was synthesized, activated (at different temperature: 120-600 degrees C) and tested for heterogeneous esterification of FFA (oleic acid) present in sunflower oil (5 wt.%). The catalyst samples were characterized by BET, TG/DTG, XRD and FTIR analyses. Obtained results showed that catalyst activated at 500 degrees C for 2 h in air atmosphere gave the maximal conversion of oleic acid (similar to 97%). Repeated use of catalyst without additional catalyst treatment or re-activation indicated that catalyst posses desired stability and activity. A pseudo-homogeneous kinetic model was proposed with good agreement between calculated and experimental data.

The transesterification of triglycerides (vegetable oil) with methanol using CaO·ZnO mixed oxides catalyst were conducted to produce FAME (Fatty Acid Methyl Esters, i.e. biodiesel). Catalyst was synthesized by ball milling of CaO and ZnO powder mixture (using molar ratio of Ca and Zn of 1:2 and 1:4) with the addition of water, as well as solely by ball milling (molar ratio of 1:2) of mentioned powders and subsequent. After ball milling prepared mixtures were calcinatied at 700 °C in air atmosphere. The samples of formed catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The particle size distribution as well as the base strength using Hammett indicator was determined, too. CaO.ZnO catalysts were used in the methanolysis of sunflower oil, at 60 °C and 1 bar, using molar ratio of sunflower oil to methanol of 1:10 and with 2 wt% of catalyst based on oil weight. All catalysts exhibited good activity in the methanolysis of sunflower oil, with the yield of FAME above 90 % after 4 hours of reaction.

U ovoj doktorskoj disertaciji ispitivani su kinetika hidrodestilacije, prinos, sastav i frakcionisanje etarskog ulja ploda kleke (Juniperus communis L.) ubrane na Šar planini, Mokroj gori, Rogozni i Kopaoniku. Određeni su prinos, sastav i fizičko-hemijske osobine etarskih ulja i razvijen dvoparametarski model kinetike hidrodestilacije etarskog ulja iz ploda kleke. Model je zasnovan na pretpostavci da se u početnoj fazi etarsko ulje sa površine čestica biljnog materijala, ili blizu nje, brzo „ispira“ („brza“ hidrodestilacija), iza koje sledi difuzija etarskog ulja iz unutašnjosti čestica biljnog materijala prema njihovoj spoljnoj površini („spora“ hidrodestilacija). Pokazano je vrlo dobro slaganje razvijenog modela sa eksperimentalnim podacima u fazi „spore“ hidrodestilacije, kao i odstupanje u fazi „brze“ hidrodestilacije. Model je potvrđen u slučaju hidrodestilacije etarskog ulja ne samo ploda kleke, već i drugih biljnih vrsta. Razvijeni dvoparametarski model se podudara sa troparametarskim fenomenološkim modelom u fazi „spore“ hidrodestilacije, za razliku od jednoparametarskih modela zasnovanih na nestacionarnoj difuziji i kinetici prvog reda, koji nisu pogodni za opisivanje kinetike hidrodestilacije etarskog ulja ploda kleke. U cilju praćenja promene sastava etarskog ulja u toku hidrodestilacije izdvojene su frakcije i GC-MS analizom ispitan njihov sastav. Utvrđeno je da se sastav etarskog ulja značajno menja u toku procesa. U prvim frakcijama dominiraju lako isparljive komponente: α-pinen, sabinen, mircen i limonen, a u frakcijama na kraju teško isparljive: izokariofilen, humulen, germakren D i germakren B. Zbog neuporedivo veće vrednosti komponenata i njihovih frakcija od etarskog ulja, proces frakcionisanja je izveden u toku hidrodestilacije sa ugrađenom rektifikacionom kolonom od 36 teorijskih podova. Istovremenom hidrodestilacijom i rektifikacijom dobijene su dve frakcije: prva, u kojoj dominiraju lako isparljive komponente od α-pinena do 1-terpinen-4-ola i, The kinetics of hydrodistillation, as well as the yield, the composition, the physico-chemical properties and the fractionation of essential oil from juniper (Juniperus communis L.) berries collected at the Šara, Mokra gora, Rogozna and Kopaonik montains were studied. The yield, the composition and the physico-chemical properties of the essential oils were determined. A two parameter model of the essential oil hydrodistillation kinetics was developed, which was based on the assumption that in the initial process stage, the essential oil from the exteranal surface of plant berries, or close to it, was „washed out“ very fast („fast“ hydrodistillation) followed by the diffusion of essential oil through berries toward the external surface („slow“ hydrodistillation). A good agreement between the model and the experimental data was found only in the stage of „slow“ hydrodistillation. The model was also proved for the hydrodistillation of essential oils from different parts of various plants. Derived model was shown to fit very well the experimental data during the whole hydrodistillation process, while the simpler one-parameter models based on the unsteady-state diffusion and the first-order kinetics were not applicable. Several fractions of an essential oil were collected during the hydrodistillation process and their compostion was determined by GC-MS. The first fractions contained mainly easily-volatile constituents such as α-pinene, sabinene, myrcene and limonene, while the fractions collected during the final phase of the hydrodistillation contained heavily-volatile components such as isocaryophyllene, humulene, germacrene D and germacrene B. To get the compounds and the fractions more valuable than the original essential oil, hydrodistiilation and fractionation were simultaneously carried out using rectification column having 36 theoretical plates. By this, so called simultaneous hydrodistiilation and rectification, two fractions were obtained: one having easily-vol

A wide spectrum of phytochemicals could be isolated from sage (Salvia officinalis L) using different extraction or distillation technique: the supercritical fluid extraction (SFE), the volatiles compounds (monoterpenes and sesquiterpenes) isolation using hydrodistillation or higher molecular compounds with Soxhlet extraction or ultrasound-assisted extraction. The combination of ultrasound-assisted extraction followed by re-extraction of obtained extract with supercritical CO2 was performed in this study. The goal of performed investigation was to concentrate diterpenes present in sage extract which are generally considered to be responsible for antioxidant activity of extracted compounds. The fractionation using the supercritical CO2, and different combination of the ultrasound-assisted solvent extractions (water-ethanol mixture or only water) followed by supercritical CO2 re-extraction of obtained extract or treated plant material were analyzed and compared. Based on the results of these investigations it could be proposed the best extraction procedure: the ultrasound pretreatment of plant material with distilled water and re-extraction of plant material (residue) using supercritical CO2. That procedure gives two valuable products: the ultrasound extract which is rich in sugars and possess the immunomodulatory activity and supercritical extract which is rich in diterpenes and sesquiterpenes.

Cilј оvоg rаdа biо је оdrеđivаnjе аntiоksidаtivnе аktivnоsti frаkciја ruzmаrinа (Rosmarinus officinalis), žаlfiје (Salvia officinalis), timiјаnа (Thymus vulgaris) i izоpа (Hyssop officinalis), kао i hеmiјskа аnаlizа izоlоvаnih frаkciја. Аntiоksidаtivnе frаkciје su izоlоvаnе primеnоm frаkciоnе еkstrаkciје sа nаtkritičnim uglјеnik(IV)-оksidоm nа pritisku оd 35 MPa i tеmpеrаturi оd 100°C. Zа оdrеđivаnjе аntiоksidаtivnе аktivnоsti izоlоvаnih frаkciја primеnjivаnа је еlеktrоn spin rеzоnаntnа (ESR) spеktrоskоpiја. Dеfinisаnjе аntiоksidаtivnе аktivnоsti dаtih frаkciја vršilо sе mеrеnjеm njihоvе spоsоbnоsti dа "hvаtајu" 1,1-difеnil-2-pikrilhidrаzil rаdikаlе (DPPH) i hidrоksil rаdikаlе. Оdrеđivаnjе spоsоbnоsti аntiоksidаtivnih frаkciја dа inhibirајu lipidnu pеrоksidаciјu vršilо sе mеrеnjеm pеrоksidnоg brоја u suncоkrеtоvоm ulјu prеmа stаndаrdnоm pоstupku ISO 3960:1977. Аntiоksidаtivnа аktivnоst еkstrаkаtа upоrеđivаnа је sа аktivnоšću butilоvаnоg hidrоksiаnizоlа (BHA) i kоmеrciјаlnоg ruzmаrinskоg еkstrаktа Flavor' Plus™. Hеmiјskа аnаlizа pоmоću HPLC-DAD/ESI-ToF-MS bilа је usmеrеnа nа kvаntitаtivnо оdrеđivаnjе kаrnоsоlа i kаrnоsоlnе kisеlinе, kојi prеdstаvlјајu јеdinjеnjа zа kоја sе vеruје dа pоsеduјu nајvеću аntiоksidаtivnu аktivnоst u ispitivаnim frаkciјаmа. U tоm cilјu kоristili su sе čisti stаndаrdi оvih јеdinjеnjа dоk је idеntifikаciја оstаlih јеdinjеnjа bilа tеntаtivnа. Nа оsnоvu DPPH rаdikаl mеtоdе rеdоslеd оd nајјаčе dо nајslаbiје аntiоksidаtivnе аktivnоsti biо је: BHA, еkstrаkt timiјаnа, Flavor' Plus™, ekstrakt ruzmarina, ekstrakt žalfije i ekstrakt izopa, dok je pri hidroksil radikal metodi redosled bio: Flavor' Plus™, еkstrаkt žаlfiје, еkstrаkt ruzmаrinа, еkstrаkt izоpа, BHA i еkstrаkt timiјаnа. Svi ispitivаni еkstrаkti pоkаzаli su sе kао inhibitоri lipidnе pеrоksidаciје suncоkrеtоvоg ulја. Nајbоlјu аntiоksidаtivnu аktivnоst mеđu ispitivаnim еkstrаktimа pоkаzао је еkstrаkt ruzmаrinа. Nа оsnоvu vrеdnоsti pеrоksidnоg brоја аntiоksidаtivnа аktivnоst ispitivаnih bilјnih, The aim of the present work was to determine the antioxidatnt activity of fractions from rosemary (Rosmarinus officinalis), sage (Salvia officinalis), thyme (Thymus vulgaris) and hyssop (Hyssop officinalis), and chemical analysis of obtained fractions. In order to isolate antioxidant fractions method of fractional supercritical extraction with carbon dioxide at 35 MPa and 100°C was applied. Antioxidant activity of obtained extracts was determined by measuring their ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and hydroxyl radical using electron spin resonance (ESR) spectroscopy. The protective effect of added SFE extracts on the oxidative stability of sunflower oil was followed by determination of its peroxide value (PV) by the official method ISO 3960:1977 during storage at 98°C. The antioxidant activity of the extracts was compared to the activity of butylated hydroxyanisole (BHA) and commercial rosemary extract Flavor' Plus™. Chemical analysis of obtained antioxidant extracts was performed using HPLC-DAD/ESI-ToF-MS. Carnosol and carnosic acid, among the main antioxidant compounds present in examinated extracts, were quantified with regard to pure standard. Identification of the other compounds was tentative. It was shown that in DPPH radical assay the order from the strongest to the weakest antioxidant activity was: BHA, thyme extract, Flavor' Plus™, rosemary and sage extracts, and hyssop extract, while in hydroxyl radical assay order was: Flavor' Plus™, sage extract, rosemary extract, hyssop extract, BHA and thyme extract. All investigating extracts were effective on retarding lipid oxidation of sunflower oil. Among them, rosemary extract exhibited the best antioxidative activity. On the basis of peroxide value assay, antioxidant activity of the investigated plant extracts after 12 h of storage at 98°C followed the order: rosemary extract > BHA > sage extract > Flavor' Plus™ > thyme extract > hyssop extract. Results of the present study

Tema ove doktorske disertacije je ispitivanje bubrenja biljnog materijala pod uticajem natkritičnog ugljenik(IV)-oksida, kao i efekata koje bubrenje ima na proces natkritične ekstrakcije (NKE). Na rezultate eksperimenata u kojima je praćena kinetika procesa NKE primenjen je matematički model na nivou sekrecione strukture i model Sovove, kako bi se promene do kojih dolazi usled bubrenja biljnog materijala kvantitativno izrazile preko parametara modela. Ispitano je bubrenje glandularnih trihoma biljaka familije Lamiaceae, bubrenje hmelja u vidu mlevenih čestica biljnog materijala i industrijskih granulata, i bubrenje čestica korena odoljena i rizoma đumbira. Ispitivanja su vođena u pravcu optimizacije procesa NKE u odnosu na potrošnju natkritičnog fluida i energije. Za proces NKE etarskih ulja iz glandularnih trihoma razvijen je kompleksan matematički model koji uključuje raspodelu vremena pucanja glandularnih trihoma, koji opisuje proces NKE sa znatno većom tačnošću u odnosu na postojeće matematičke modele. Za ekstrakciju na višim pritiscima definisan je optimalan predtretman biljnog materijala kojim se postižu značajne uštede natkritičnog fluida. U slučaju bubrenja hmelja razmatrani su fenomeni prenosa mase u šišaricama i granulatima hmelja izloženim natkritičnom fluidu na različitim uslovima. Rezultati su objasnili pojave koje se dešavaju na industrijskom nivou, a pre svega nepoželjno očvršćavanje ekstrakcione pogače. Parametri procesa (koeficijenti difuzije kroz čvrstu fazu) opisani su primenom matematičkih modela na eksperimentalne rezultate. U slučaju bubrenja korena odoljena i rizoma đumbira, izborom optimalnog predtretmana ostvarene su značajne uštede natkritičnog fluida. Parametri procesa (koeficijenti prenosa mase kroz čvrstu fazu) opisani su primenom matematičkih modela na eksperimentaln rezultate., The subject of this disertation is the swelling of plant material under the influence of supercritical carbon dioxide, as well as the effects of swelling on the process of supercritical fluid extraction (SFE). The results of experiments on the kinetics of the SFE processes were modeled using a mathematical model on the micro-scale and the Sovova’s model, which quantitatively express, through the parameters of the model, the changes that occur due to the swelling of plant material. The swelling of glandular trichomes of plants of the Lamiaceae family, swelling of hop in the form of ground particles of plant material and industrial granulates, and swelling of the particles of valerian root and rhizome of ginger were observed. The tests were conducted in order to examine the possibility of optimization the SFE process in respect to the consumption of supercritical fluids and energy. For the process of SFE of essential oils from glandular trichomes, a complex mathematical model which includes the cracking time distribution for glandular trichomes was developed. The new model describes the process of SFE with significantly higher accuracy than the existing mathematical models. For extraction at higher pressures the optimal pretreatment of plant material is defined with the goal to achieve significant savings of supercritical fluid. In the case of swelling of hops, the mass transport phenomena in granulates and cones exposed to supercritical fluid in various conditions were considered. The results explained phenomena that occur on industrial scale, especially undesirable hardening of the extraction cake. Process parameters (diffusion coefficients in the solid phase) are described by applying mathematical models to experimental results. In the case of swelling of valerian root and rhizome of ginger, significant savings of supercritical fluid consumption were achieved by choosing the optimal treatment. Process parameters (coefficients of mass transfer through the solid phas

The subject of this disertation is the swelling of plant material under the influence of supercritical carbon dioxide, as well as the effects of swelling on the process of supercritical fluid extraction (SFE). The results of experiments on the kinetics of the SFE processes were modeled using a mathematical model on the micro-scale and the Sovova’s model, which quantitatively express, through the parameters of the model, the changes that occur due to the swelling of plant material. The swelling of glandular trichomes of plants of the Lamiaceae family, swelling of hop in the form of ground particles of plant material and industrial granulates, and swelling of the particles of valerian root and rhizome of ginger were observed. The tests were conducted in order to examine the possibility of optimization the SFE process in respect to the consumption of supercritical fluids and energy. For the process of SFE of essential oils from glandular trichomes, a complex mathematical model which includes the cracking time distribution for glandular trichomes was developed. The new model describes the process of SFE with significantly higher accuracy than the existing mathematical models. For extraction at higher pressures the optimal pretreatment of plant material is defined with the goal to achieve significant savings of supercritical fluid. In the case of swelling of hops, the mass transport phenomena in granulates and cones exposed to supercritical fluid in various conditions were considered. The results explained phenomena that occur on industrial scale, especially undesirable hardening of the extraction cake. Process parameters (diffusion coefficients in the solid phase) are described by applying mathematical models to experimental results. In the case of swelling of valerian root and rhizome of ginger, significant savings of supercritical fluid consumption were achieved by choosing the optimal treatment. Process parameters (coefficients of mass transfer through the solid phas, Tema ove doktorske disertacije je ispitivanje bubrenja biljnog materijala pod uticajem natkritičnog ugljenik(IV)-oksida, kao i efekata koje bubrenje ima na proces natkritične ekstrakcije (NKE). Na rezultate eksperimenata u kojima je praćena kinetika procesa NKE primenjen je matematički model na nivou sekrecione strukture i model Sovove, kako bi se promene do kojih dolazi usled bubrenja biljnog materijala kvantitativno izrazile preko parametara modela. Ispitano je bubrenje glandularnih trihoma biljaka familije Lamiaceae, bubrenje hmelja u vidu mlevenih čestica biljnog materijala i industrijskih granulata, i bubrenje čestica korena odoljena i rizoma đumbira. Ispitivanja su vođena u pravcu optimizacije procesa NKE u odnosu na potrošnju natkritičnog fluida i energije. Za proces NKE etarskih ulja iz glandularnih trihoma razvijen je kompleksan matematički model koji uključuje raspodelu vremena pucanja glandularnih trihoma, koji opisuje proces NKE sa znatno većom tačnošću u odnosu na postojeće matematičke modele. Za ekstrakciju na višim pritiscima definisan je optimalan predtretman biljnog materijala kojim se postižu značajne uštede natkritičnog fluida. U slučaju bubrenja hmelja razmatrani su fenomeni prenosa mase u šišaricama i granulatima hmelja izloženim natkritičnom fluidu na različitim uslovima. Rezultati su objasnili pojave koje se dešavaju na industrijskom nivou, a pre svega nepoželjno očvršćavanje ekstrakcione pogače. Parametri procesa (koeficijenti difuzije kroz čvrstu fazu) opisani su primenom matematičkih modela na eksperimentalne rezultate. U slučaju bubrenja korena odoljena i rizoma đumbira, izborom optimalnog predtretmana ostvarene su značajne uštede natkritičnog fluida. Parametri procesa (koeficijenti prenosa mase kroz čvrstu fazu) opisani su primenom matematičkih modela na eksperimentaln rezultate.

The separation in a batch vacuum column of the essential oil of common juniper berries (Juniperus communis L., from the southern part of Serbia) was analyzed. The main goal of the analyzed separation process was to isolate several fractions from the essential oil which mainly contained á-pinene, sabinene and myrcene. These compounds contain about 65 mass% of the essential oil produced by hydrodistillation from the juniper berries originated from the southern part of Serbia. The results of experimental work in a laboratory column with 36 theoretical stages under vacuum (8.0-3.35 kPa) was simulated using Aspen software, and a proposed mathematical model was used to analyze some other operating conditions for fractionation of juniper berry's oil (number of plates: 25, 36 and 45 and reflux ratio: 2-10). According to the results of performed simulations, the most acceptable separation procedure which takes into account the prices of raw materials and distillate (á-pinene) as well as consumed energy was proposed., U ovom radu je ispitivana separacija etarskog ulja iz bobica kleke (Juniperus communis L. sa podneblja južne Srbije) postupkom šaržne vakuum destilacije. Glavni cilj laboratorijskih ispitivanja je usmeren ka izdvajanju pojedinih frakcija iz etarskog ulja kleke koje sadrže u većem procentu á-pinen, sabinen i mircen, a čine 65 mas% etarskog ulja dobijenog hidrodestilacijom bobica kleke. Rezultati eksperimentalnih ispitivanja sprovedenih šaržnom destilacijom pod vakuumom (8,0-3,35 kPa) u koloni sa 36 teorijskih podova su bili osnova za definisanje odgovarajućeg matematičkog modela i njegovog rešavanja primenom softverskog paketa Aspen. Dobijeno je dobro slaganje između eksperimentalnih vrednosti i vrednosti izračunatih na osnovu ovog modela. Potvrđena korektnost modela iskorišćena je za analizu uticaja različitih operativnih parametara (refluksni odnos od 2 do 10) i konstrukcionih karakteristika kolone (broj podova: 25, 36 i 45) na efekte separacije etarskog ulja kleke. Rezultati su pokazali, na osnovu analize uticaja cene ulazne sirovine, cene izdvojenih frakcija (á-pinen; smeše á-pinena sabinena, mircena) i ukupno utrošene energije za separaciju, da je u laboratorijskim uslovima izvedeno frakcionisanje etarskog ulja kleke najprihvatljivije.

Swelling of plant material belonging to several plant families and the influence of swelling on supercritical fluid extraction process were investigated in this study. While swelling of Lamiaceae family species as well as hop cones and pellets occurred during the exposure of plant material to supercritical carbon dioxide, swelling of valerian root and ginger rhizome happened after the decompression step. Optimal pretreatment of herbaceous matrix which will enable commencement of continuous extraction from already swollen plant material was defined on the basis of swelling test results. Experimental results were modeled and energy savings due to the optimal processing on the laboratory scale were calculated. Sorption of carbon dioxide into the hop pellet was measured and the diffusion coefficient in the solid phase was determined. Obtained results indicated that the effective diffusion coefficient in the hop pellet was increased by one order of magnitude due to swelling.

Today, homogeneous base-catalyzed methanolysis is the most frequently used method for industrial biodiesel production. High requirements for the quality of the feedstocks and the problems related to the huge amount of wastewaters have led to the development of novel biodiesel production technologies. Among them, the most important is heterogeneous base-catalyzed methanolysis, which has been intensively investigated over the last decade in order to develop new catalytic systems, optimize the reaction conditions and to recycle catalysts. These studies are a basis for continuous development of biodiesel production on an industrial scale in the near future. The presented work summarize up-to-date studies on biodiesel production by heterogeneous base-catalyzed methanolysis. The main goals were to point out the application of different base compounds as catalysts, the methods of catalyst preparation, impregnation on carriers and recycling as well as the possibilities to improve existing base-catalyzed biodiesel production processes and to develop novel ones., Homogena bazno katalizovana metanoliza je najčešće primenjivan postupak dobijanja biodizela u industrijskim uslovima. Visoki zahtevi u pogledu kvaliteta uljnih sirovina i ekološki problemi otpadnih voda doprineli su razvoju novih postupaka sinteze biodizela. Među njima značajno mesto zauzima heterogena bazno katalizovana metanoliza ulja, koja je u poslednjoj deceniji intenzivno proučavana sa aspekta razvoja novih katalitičkih sistema, optimizacije reakcionih uslova metanolize i mogućnosti reciklovanja katalizatora. Ispitivanja ovakvih sistema čine osnovu za razvoj kontinualnih postupaka heterogene bazno katalizovane metanolize, na kojima će se u bliskoj budućnosti bazirati industrijska proizvodnja biodizela. U ovom radu analizirana su dosadašnja ispitivanja postupaka dobijanja biodizela heterogenom bazno katalizovanom metanolizom. Cilj rada je da se ukaže na primenu različitih baznih jedinjenja kao katalizatora, načine njihove pripreme, nanošenja na nosače i recikliranja, kao i na mogućnosti unapređenja postojećih i razvoja novih procesa dobijanja biodizela baznom katalizom.

In this study, catalysts for fatty acid methyl esters (FAME or biodiesel) synthesis with K2CO3 as the active component on an alumina/silica support were synthesized using the sol-gel method, which was followed by drying the 'dense' wet gels with supercritical carbon dioxide to obtain the aerogels. The prepared catalysts were characterized by XRD analysis, FTIR spectroscopy and N2 physisorption at 77 K, and tested in the methanolysis of sunflower oil. The effects of reaction variables, such as reaction time, temperature and methanol to oil molar ratio, on the yield of FAME were investigated. The aerogel catalysts with K2CO3 as the active component on an alumina/silica support exhibited good activity in the methanolysis of sunflower oil. The leaching of potassium when the catalyst was in contact with pure methanol under the working conditions of methanolysis was also tested in this study, indicating that it occurred only at higher temperatures, while at lower ones, it was negligible., U ovom radu katalizator za sintezu metil estara masnih kiselina (MEMK ili biodizel) sa K2CO3 kao aktivnom komponentom na alumosilikatnom nosaču sintetizovan je sol-gel metodom nakon čega je dobijeni gel sušen uz prisustvo natkritičnog ugljen dioksida da bi se dobio aerogel. Za karakterizaciju sintetizovanih katalizatora korišćene su metode XRD, FTIR i N2 fizisorpcija na 77 K i katalizatori su testirani u reakciji metanolize suncokretovog ulja. Katalizator je testiran u reakciji metanolize suncekrotovog ulja i sintezi MEMK. Ispitan je uticaj različitih parametara kao što su vreme, temperatura i molarni odnos metanol : ulje na prinos MEMK. Aerogel katalizator sa K2CO3 kao aktivnom komponentom na alumosilikatnom nosaču pokazao je dobru katalitičku aktivnost u reakciji metanolize suncokretovog ulja. Izluživanje kalijuma u kontaktu sa metanolom na radnim uslovima metanolize takođe je testirano u ovom radu, pokazujući da ono postoji na višim temperaturama, dok je na nižim zanemarljivo.

The supercritical carbon dioxide (SFE) extraction of Dalmatian sage (Salvia officinalis L) was investigated and compared to extraction performed by Soxhlet ethanol-water (70:30) mixture extraction (SE) and hydrodistillation (HD). The supercritical extraction allowed isolation of wide spectrum of phytochemicals, while other applied methods were limited to either volatiles (HD) or high molecular compounds isolation (SE). The kinetics of the supercritical extraction and fractionation within the pressure range of 10-30 MPa at 50 degrees C were also analyzed as well as the chemical compositions of total extract and partial or differential fractions isolated at different CO2. consumption. Volatile fraction could be isolated at low pressure and low CO2 consumption, whereby the pressures between 10 and 15 MPa followed by increased CO2 consumption were favourable for obtaining desired selectivity of diterpenes which contain compounds with expressed antioxidative characteristics.

The analysis of phase equilibrium between methanol and glycerides during methyl esters of fatty acids (FAME or biodiesel) synthesis at high pressure and temperature is very important for describing the kinetic and process design. It was studied at pressure between 1.1 and 28.0 MPa and temperature from 150 to 270 degrees C. The transition of phases and composition of identified phases was calculated using RK-Aspen EOS and obtained values were also compared to experimentally determined data at subcritical condition (1.1-4.5 MPa and 150-210 degrees C). Results of experimental investigation, as well as performed simulation of some specified composition of reaction mixture, showed that system of triglycerides and methanol, at the beginning of reaction (at all analysed conditions except for supercritical state of mixture) is in equilibrium between two liquid phases. During the methanolysis of triglycerides, the phase's distribution was changed accordingly and it highly depends on actual composition of reaction mixture, temperature and pressure. Calculated and measured values indicated that distribution of methanol between the oil phase, the methyl esters, and the glycerol rich phase exists and depends of working condition. As a consequence of fact, that the methanolysis of triglycerides (oil) is mainly realized in the oil-rich phase, at the end of reaction, after all triglycerides are converted into FAME and glycerol, the oil phase disappears. Furthermore, according to the results of phase composition calculation, it was shown that from the beginning to the end of reaction one phase only exists, for methanolysis performed at 270 degrees C and 20.0 MPa.

U ovom radu proučavani su višekomponentni katalitički sistemi u kojima su aktivna komponenta (metalniNi) i pogodni metali (Mg, Ag i Cu) naneseni na pripremljeni nosač (aktivirani dijatomit), kao i njihovaprimena u svojstvu katalizatora u procesu parcijalne hidrogenizacije jestivih biljnih ulja.Polazni materijal korišćen za sintezu nosača katalizatora predstavljao je sirovi dijatomit domaćeg porekla(ležište dijatomita Baroševac, istočni deo Kolubarskog ugljenog basena). Modifikacijom svojstava sirovogdijatomita hemijskom i termičkom obradom dobijen je nosač katalizatora sa visokim sadržajem silicijumdioksida. Ispitivanja teksturalnih svojstava i granulometrijskog sastava su pokazala da dijatomitni nosač imamakroporoznu strukturu i povoljan granulometrijski sastav, odgovarajući za dobijanje nikl katalizatora kojise koriste u procesima parcijalne hidrogenizacije biljnih ulja.Izvršena je sinteza nekoliko uzoraka katalizatora precipitacijom jedinjenja nikla i odgovarajućih metala izvodenih rastvora njihovih nitratnih soli na pripremljeni dijatomitni nosač korišćenjem natrijum karbonata(PDI katalizatori) i uree (DPU katalizatori) u svojstvu precipitanta.Obavljeni su obimni eksperimenti koji su obuhvatili ispitivanja uticaja uslova sinteze prekursora PDI- i DPUNi/D katalizatora na stepen redukcije. Proučavanjem uticaja SiO2/Ni molskog odnosa i brzine zagrevanjana stepen redukcije prekursora PDI-Ni/D katalizatora utvrđeno je da manji SiO2/Ni m.o. i manje brzinezagrevanja povećavaju stepen redukcije. Ispitivanja uticaja DP vremena na stepen redukcije prekursoraDPU-Ni/D katalizatora su pokazala da kraća DP vremena omogućavaju veći stepen redukcije.Fizičko-hemijska svojstva prekursora PDI- i DPU-Ni/D katalizatora okarakterisana su primenom sledećihmetoda: (1) standardna kvantitativna hemijska analiza; (2) rendgenostrukturna (XRD) i infracrvena (IR)spektroskopija; (3) Hg-porozimetrija i N2-fizisorpcija; (4) temperaturno-programirana redukcija (TPR); (5)H2-hemisorpcija; (6) sken, Multicomponent catalytic systems consisting of active component (metallic Ni) and appropriate metals (Mg,Ag, Cu) deposited onto a prepared support (activated diatomite) were investigated, as well as theirapplication as catalysts in the process of partial hydrogenation of edible oils.Starting material used for the synthesis of the catalyst support was raw diatomite from domestic sources(Baroševac diatomite deposit, eastern zone of the Kolubara coal basin). Raw diatomite properties weremodified through chemical and thermal treatment resulting in a catalyst support with high silicon oxidecontent. Investigation of the textural properties and granulometric composition showed that the obtainedcatalyst support has macroporous structure and convenient granulometric composition appropriate for theobtention of Ni containing catalysts for the partial hydrogenation of vegetable oils.Synthesis of several catalyst samples was performed by the precipitation of Ni compounds and appropriatemetals from aqueous solutions of their nitrate salts onto the prepared diatomite support, using sodiumcarbonate (PDI catalysts) and urea (DPU catalysts) as precipitants.Thorough experiments were carried out in order to investigate the influence of the PDI- and DPU-Ni/Dcatalyst precursor synthesis conditions on the degree of reduction. Investigation of the influence of theSiO2/Ni molar ratio and heating rate on the degree of reduction of the PDI-Ni/D catalyst precursor showedthat lower SiO2/Ni molar ratio and lower heating rate increase the reduction degree. Investigation of thedependence of the degree of reduction on the DP time indicated that shorter DP times enable higherreduction degree.Physico - chemical characterization of the PDI- and DPU-Ni/D catalyst precursors was performed using thefollowing methods: (1) standard quantitative chemical analysis; (2) X-ray diffraction (XRD) and infrared (IR)spectroscopy; (3) Hg-porosimetry and N2-physisorption (4) temperature-programmed reduction (TPR); (5