Synthesis and purification of fatty acid ethyl ester by ultrafiltration

Membranski procesi su separacijski procesi kojima se pomoću membrane ulazna struja odvaja na retentat (dio ulazne struje koji se zadržao na membrani) i permeat (dio ulazne struje koji je prošao kroz membranu). Odvajanje je temeljeno na sposobnosti membrane da jednu komponentu iz ulazne smjese lakše transportira, u odnosu na druge komponente, što proizlazi iz fizikalnih i kemijskih svojstava membrane i komponente koju prožima. U ovome radu provedena je membranska ultrafiltracija smjese etilnih estera viših masnih kiselina, etanola, suncokretovog ulja i glicerola. Za razdvajanje korištene su 3 vrste polimernih membrana – PT membrane proizvedene od polietersulfona s graničnom molekulskom masom (MWCO) od 5000 Da te poliamidne membrane GK s MWCO od 3000 Da i GH s MWCO od 2000 Da. Esteri viših masnih kiselina (biodizel) proizvedeni su reakcijom transesterifikacije, a cilj je bio izravno iz reakcijske smjese izdvojiti samo etilne estere. Najučinkovitija membrana za uklanjanje glicerola pokazala se PT membrana pri radnom tlaku od 6 bara (6×105 Pa) koja je uklonila 38,3 % glicerola i 32,5 % etanola iz smjese. Za uklanjanje etanola iz smjese najučinkovitija je bila GK membrana također pri radnome tlaku od 6 bara koja je uklonila 57,8 % etanola iz smjese i 8,2 % glicerola.Membrane separation is a process in which the membrane separates the inlet stream on retentate (part of the inlet stream retained on the membrane) and the permeate (part of the inlet stream that passed through the membrane). Separation is based on the ability of the membrane to transport one component from the inlet stream more easily than other components based on the physical and chemical properties of the membrane and the permeating component. In this thesis a membrane ultrafiltration separation of fatty acid ethyl esters from mixture of ethanol, sunflower oil and glycerol, was conducted. Three types of polymer membranes were used: PT membrane produced by polyethersulfone with a molecular weight cut-off (MWCO) of 5000 Da and two polyamide membranes, GK with a MWCO of 3000 Da and GH with a MWCO of 2000 Da. Fatty acid ethyl ester (biodiesel) were produced by transesterification and the goal was to isolate them directly from the mixture after the reaction. The most efficient membrane for glycerol removal is PT membrane working at 6 bar (6×105 Pa). It reduced the concentration of glycerol by 38,3 % and ethanol by 32,5 % compared to starting mixture. The most efficient membrane for reducing the concentration of ethanol from the starting mixture is GK membrane under the same conditions (6 bar) and reduction of 57,8 % of ethanol and 8,2 % of glycerol, compared to concentration in starting mixture, was achieved

Influence of carbon nanotube addition on polymer conductivity

Polimerni nanokompoziti su novi pripadnici skupine kompozitnih materijala koji zbog svojih specifičnosti i još uvijek neistraženih mogućnosti privlače pozornost kako industrije, tako i znanosti. Nanopunila koja pokazuju najbolje karakteristike u kombinaciji s polimernim matricama su ugljikove nanocjevčice zbog iznimnih mehaničkih i električnih svojstava. U ovom završnom radu istraživan je utjecaj dodatka ugljikovih nanocjevčica na vodljivost polimera. Iz pregleda rezultata dosadašnjih istraživanja utvrđeno je da vodljivost u polimernim nanokompozitima s ugljikovim nanocjevčicama ovisi o brojnim čimbenicima, a najznačajniji od njih su udio, omjer dimenzija i modifikacija ugljikovih nanocjevčica, karakteristike matrice te dispergiranost i usmjerenost ugljikovih nanocjevčica u polimernoj matrici. Rezultati pregledanih istraživanja pokazuju da se vodljivost nanokompozita značajno povećava već pri vrlo niskim koncentracijama ugljikovih nanocjevčica, a s obzirom na način priprave, odnosno dispergiranosti ugljikovih nanocjevčica, može se zaključiti da se veća vodljivost postiže kod aglomeriranih uzoraka. U nekim sustavima modifikacija uzrokuje promjenu strukture nanocjevčica zbog koje dolazi do smanjenja vodljivosti nanocjevčica što nadvladava poboljšanu dispergiranost te neki sustavi s modificiranim nanocjevčicama imaju nižu vodljivost, dok u nekim sustavima modifikacija doprinosi povećanju vodljivosti boljim međudjelovanjima i raspodijeljenošću punila u matrici. Analizom mezopskog oblika ugljikovih nanocjevčica, odnosno u trodimenzionalnim sustavima omjera (lsp/d)^2, utvrđeno je da za isti udio nanocjevčica vodljivost linearno raste povećanjem omjera dimenzija MWCNT-a. S obzirom na usmjerenost ugljikovih nanocjevčica u polimernim nanokompozitima, utvrđeno je da je porastom izotropnosti (povećanje FWHM) učestaliji kontakt između SWCNT-a i pri kritičnoj vrijednosti FWHM stvara se vodljiva mreža te se ujedno povećava i vodljivost, ali samo do određene FWHM vrijednosti, iznad koje se počinje smanjivati vodljivost. Što se tiče karakteristika matrice, značajnije poboljšanje električnih svojstava postiže se s amorfnim nego kristaličnim matricama.Polymeric nanocomposites are the new members of composite materials group which, due to their specifics and still insufficiently researched possibilities, draw the attention of industry, as well as science. Nanofillers which show the best characteristics combined with polymer matrices are carbon nanotubes due to their exceptional mechanical and electrical properties. This Bachelor thesis is about the research of the influence of the addition of carbon nanotubes to the conductivity of polymers. By examining results of previous researches, it was determined that conductivity in polymeric nanocomposites with carbon nanotubes depends on a number of factors, the most significant of them being: content, dimension ratio and modification of carbon nanotubes, matrix characteristics and the dispersion and alignment of carbon nanotubes in a polymer matrix. The results from the researches show that the conductivity of polymeric nanocomposites increases significantly even at low concentrations of carbon nanotubes, and given the way of preparation, or dispersion of carbon nanotubes, it can be concluded that the higher conductivity is achieved with agglomerated samples. In some systems, modification causes a change of structure of the nanotubes that leads to decrease in conductivity of the nanotubes, which overcomes the improved dispersion, so some systems with modified nanotubes have lower conductivity, while in some systems, the modification contributes to the increase in conductivity through better interaction and distribution of fillers in the matrix. By analysing the mesopic shape of carbon nanotubes, that is, in three-dimensional systems with a ratio (lsp/d)^2, it was determined that for the same content of nanotubes, the conductivity increases linearly with the increase of the dimension ratio of MWCNTs. Considering the alignment of carbon nanotubes in polymeric nanocomposites, it was established that the contact between SWCNTs is more frequent with the increase of isotropy (increase of FWHM) and that, at critical value of FWHM, a conductive network is created and conductivity is increased as well, but only to a certain value of FWHM, above which the conductivity decreases. As far as matrix characteristics are concerned, a more significant improvement of electrical properties is achieved with amorphous than with crystal matrices

Synthesis and purification of fatty acid ethyl ester by ultrafiltration

Membranski procesi su separacijski procesi kojima se pomoću membrane ulazna struja odvaja na retentat (dio ulazne struje koji se zadržao na membrani) i permeat (dio ulazne struje koji je prošao kroz membranu). Odvajanje je temeljeno na sposobnosti membrane da jednu komponentu iz ulazne smjese lakše transportira, u odnosu na druge komponente, što proizlazi iz fizikalnih i kemijskih svojstava membrane i komponente koju prožima. U ovome radu provedena je membranska ultrafiltracija smjese etilnih estera viših masnih kiselina, etanola, suncokretovog ulja i glicerola. Za razdvajanje korištene su 3 vrste polimernih membrana – PT membrane proizvedene od polietersulfona s graničnom molekulskom masom (MWCO) od 5000 Da te poliamidne membrane GK s MWCO od 3000 Da i GH s MWCO od 2000 Da. Esteri viših masnih kiselina (biodizel) proizvedeni su reakcijom transesterifikacije, a cilj je bio izravno iz reakcijske smjese izdvojiti samo etilne estere. Najučinkovitija membrana za uklanjanje glicerola pokazala se PT membrana pri radnom tlaku od 6 bara (6×105 Pa) koja je uklonila 38,3 % glicerola i 32,5 % etanola iz smjese. Za uklanjanje etanola iz smjese najučinkovitija je bila GK membrana također pri radnome tlaku od 6 bara koja je uklonila 57,8 % etanola iz smjese i 8,2 % glicerola.Membrane separation is a process in which the membrane separates the inlet stream on retentate (part of the inlet stream retained on the membrane) and the permeate (part of the inlet stream that passed through the membrane). Separation is based on the ability of the membrane to transport one component from the inlet stream more easily than other components based on the physical and chemical properties of the membrane and the permeating component. In this thesis a membrane ultrafiltration separation of fatty acid ethyl esters from mixture of ethanol, sunflower oil and glycerol, was conducted. Three types of polymer membranes were used: PT membrane produced by polyethersulfone with a molecular weight cut-off (MWCO) of 5000 Da and two polyamide membranes, GK with a MWCO of 3000 Da and GH with a MWCO of 2000 Da. Fatty acid ethyl ester (biodiesel) were produced by transesterification and the goal was to isolate them directly from the mixture after the reaction. The most efficient membrane for glycerol removal is PT membrane working at 6 bar (6×105 Pa). It reduced the concentration of glycerol by 38,3 % and ethanol by 32,5 % compared to starting mixture. The most efficient membrane for reducing the concentration of ethanol from the starting mixture is GK membrane under the same conditions (6 bar) and reduction of 57,8 % of ethanol and 8,2 % of glycerol, compared to concentration in starting mixture, was achieved

Influence of carbon nanotube addition on polymer conductivity

Polimerni nanokompoziti su novi pripadnici skupine kompozitnih materijala koji zbog svojih specifičnosti i još uvijek neistraženih mogućnosti privlače pozornost kako industrije, tako i znanosti. Nanopunila koja pokazuju najbolje karakteristike u kombinaciji s polimernim matricama su ugljikove nanocjevčice zbog iznimnih mehaničkih i električnih svojstava. U ovom završnom radu istraživan je utjecaj dodatka ugljikovih nanocjevčica na vodljivost polimera. Iz pregleda rezultata dosadašnjih istraživanja utvrđeno je da vodljivost u polimernim nanokompozitima s ugljikovim nanocjevčicama ovisi o brojnim čimbenicima, a najznačajniji od njih su udio, omjer dimenzija i modifikacija ugljikovih nanocjevčica, karakteristike matrice te dispergiranost i usmjerenost ugljikovih nanocjevčica u polimernoj matrici. Rezultati pregledanih istraživanja pokazuju da se vodljivost nanokompozita značajno povećava već pri vrlo niskim koncentracijama ugljikovih nanocjevčica, a s obzirom na način priprave, odnosno dispergiranosti ugljikovih nanocjevčica, može se zaključiti da se veća vodljivost postiže kod aglomeriranih uzoraka. U nekim sustavima modifikacija uzrokuje promjenu strukture nanocjevčica zbog koje dolazi do smanjenja vodljivosti nanocjevčica što nadvladava poboljšanu dispergiranost te neki sustavi s modificiranim nanocjevčicama imaju nižu vodljivost, dok u nekim sustavima modifikacija doprinosi povećanju vodljivosti boljim međudjelovanjima i raspodijeljenošću punila u matrici. Analizom mezopskog oblika ugljikovih nanocjevčica, odnosno u trodimenzionalnim sustavima omjera (lsp/d)^2, utvrđeno je da za isti udio nanocjevčica vodljivost linearno raste povećanjem omjera dimenzija MWCNT-a. S obzirom na usmjerenost ugljikovih nanocjevčica u polimernim nanokompozitima, utvrđeno je da je porastom izotropnosti (povećanje FWHM) učestaliji kontakt između SWCNT-a i pri kritičnoj vrijednosti FWHM stvara se vodljiva mreža te se ujedno povećava i vodljivost, ali samo do određene FWHM vrijednosti, iznad koje se počinje smanjivati vodljivost. Što se tiče karakteristika matrice, značajnije poboljšanje električnih svojstava postiže se s amorfnim nego kristaličnim matricama.Polymeric nanocomposites are the new members of composite materials group which, due to their specifics and still insufficiently researched possibilities, draw the attention of industry, as well as science. Nanofillers which show the best characteristics combined with polymer matrices are carbon nanotubes due to their exceptional mechanical and electrical properties. This Bachelor thesis is about the research of the influence of the addition of carbon nanotubes to the conductivity of polymers. By examining results of previous researches, it was determined that conductivity in polymeric nanocomposites with carbon nanotubes depends on a number of factors, the most significant of them being: content, dimension ratio and modification of carbon nanotubes, matrix characteristics and the dispersion and alignment of carbon nanotubes in a polymer matrix. The results from the researches show that the conductivity of polymeric nanocomposites increases significantly even at low concentrations of carbon nanotubes, and given the way of preparation, or dispersion of carbon nanotubes, it can be concluded that the higher conductivity is achieved with agglomerated samples. In some systems, modification causes a change of structure of the nanotubes that leads to decrease in conductivity of the nanotubes, which overcomes the improved dispersion, so some systems with modified nanotubes have lower conductivity, while in some systems, the modification contributes to the increase in conductivity through better interaction and distribution of fillers in the matrix. By analysing the mesopic shape of carbon nanotubes, that is, in three-dimensional systems with a ratio (lsp/d)^2, it was determined that for the same content of nanotubes, the conductivity increases linearly with the increase of the dimension ratio of MWCNTs. Considering the alignment of carbon nanotubes in polymeric nanocomposites, it was established that the contact between SWCNTs is more frequent with the increase of isotropy (increase of FWHM) and that, at critical value of FWHM, a conductive network is created and conductivity is increased as well, but only to a certain value of FWHM, above which the conductivity decreases. As far as matrix characteristics are concerned, a more significant improvement of electrical properties is achieved with amorphous than with crystal matrices

Influence of carbon nanotube addition on polymer conductivity

Polimerni nanokompoziti su novi pripadnici skupine kompozitnih materijala koji zbog svojih specifičnosti i još uvijek neistraženih mogućnosti privlače pozornost kako industrije, tako i znanosti. Nanopunila koja pokazuju najbolje karakteristike u kombinaciji s polimernim matricama su ugljikove nanocjevčice zbog iznimnih mehaničkih i električnih svojstava. U ovom završnom radu istraživan je utjecaj dodatka ugljikovih nanocjevčica na vodljivost polimera. Iz pregleda rezultata dosadašnjih istraživanja utvrđeno je da vodljivost u polimernim nanokompozitima s ugljikovim nanocjevčicama ovisi o brojnim čimbenicima, a najznačajniji od njih su udio, omjer dimenzija i modifikacija ugljikovih nanocjevčica, karakteristike matrice te dispergiranost i usmjerenost ugljikovih nanocjevčica u polimernoj matrici. Rezultati pregledanih istraživanja pokazuju da se vodljivost nanokompozita značajno povećava već pri vrlo niskim koncentracijama ugljikovih nanocjevčica, a s obzirom na način priprave, odnosno dispergiranosti ugljikovih nanocjevčica, može se zaključiti da se veća vodljivost postiže kod aglomeriranih uzoraka. U nekim sustavima modifikacija uzrokuje promjenu strukture nanocjevčica zbog koje dolazi do smanjenja vodljivosti nanocjevčica što nadvladava poboljšanu dispergiranost te neki sustavi s modificiranim nanocjevčicama imaju nižu vodljivost, dok u nekim sustavima modifikacija doprinosi povećanju vodljivosti boljim međudjelovanjima i raspodijeljenošću punila u matrici. Analizom mezopskog oblika ugljikovih nanocjevčica, odnosno u trodimenzionalnim sustavima omjera (lsp/d)^2, utvrđeno je da za isti udio nanocjevčica vodljivost linearno raste povećanjem omjera dimenzija MWCNT-a. S obzirom na usmjerenost ugljikovih nanocjevčica u polimernim nanokompozitima, utvrđeno je da je porastom izotropnosti (povećanje FWHM) učestaliji kontakt između SWCNT-a i pri kritičnoj vrijednosti FWHM stvara se vodljiva mreža te se ujedno povećava i vodljivost, ali samo do određene FWHM vrijednosti, iznad koje se počinje smanjivati vodljivost. Što se tiče karakteristika matrice, značajnije poboljšanje električnih svojstava postiže se s amorfnim nego kristaličnim matricama.Polymeric nanocomposites are the new members of composite materials group which, due to their specifics and still insufficiently researched possibilities, draw the attention of industry, as well as science. Nanofillers which show the best characteristics combined with polymer matrices are carbon nanotubes due to their exceptional mechanical and electrical properties. This Bachelor thesis is about the research of the influence of the addition of carbon nanotubes to the conductivity of polymers. By examining results of previous researches, it was determined that conductivity in polymeric nanocomposites with carbon nanotubes depends on a number of factors, the most significant of them being: content, dimension ratio and modification of carbon nanotubes, matrix characteristics and the dispersion and alignment of carbon nanotubes in a polymer matrix. The results from the researches show that the conductivity of polymeric nanocomposites increases significantly even at low concentrations of carbon nanotubes, and given the way of preparation, or dispersion of carbon nanotubes, it can be concluded that the higher conductivity is achieved with agglomerated samples. In some systems, modification causes a change of structure of the nanotubes that leads to decrease in conductivity of the nanotubes, which overcomes the improved dispersion, so some systems with modified nanotubes have lower conductivity, while in some systems, the modification contributes to the increase in conductivity through better interaction and distribution of fillers in the matrix. By analysing the mesopic shape of carbon nanotubes, that is, in three-dimensional systems with a ratio (lsp/d)^2, it was determined that for the same content of nanotubes, the conductivity increases linearly with the increase of the dimension ratio of MWCNTs. Considering the alignment of carbon nanotubes in polymeric nanocomposites, it was established that the contact between SWCNTs is more frequent with the increase of isotropy (increase of FWHM) and that, at critical value of FWHM, a conductive network is created and conductivity is increased as well, but only to a certain value of FWHM, above which the conductivity decreases. As far as matrix characteristics are concerned, a more significant improvement of electrical properties is achieved with amorphous than with crystal matrices

Synthesis and purification of fatty acid ethyl ester by ultrafiltration

Membranski procesi su separacijski procesi kojima se pomoću membrane ulazna struja odvaja na retentat (dio ulazne struje koji se zadržao na membrani) i permeat (dio ulazne struje koji je prošao kroz membranu). Odvajanje je temeljeno na sposobnosti membrane da jednu komponentu iz ulazne smjese lakše transportira, u odnosu na druge komponente, što proizlazi iz fizikalnih i kemijskih svojstava membrane i komponente koju prožima. U ovome radu provedena je membranska ultrafiltracija smjese etilnih estera viših masnih kiselina, etanola, suncokretovog ulja i glicerola. Za razdvajanje korištene su 3 vrste polimernih membrana – PT membrane proizvedene od polietersulfona s graničnom molekulskom masom (MWCO) od 5000 Da te poliamidne membrane GK s MWCO od 3000 Da i GH s MWCO od 2000 Da. Esteri viših masnih kiselina (biodizel) proizvedeni su reakcijom transesterifikacije, a cilj je bio izravno iz reakcijske smjese izdvojiti samo etilne estere. Najučinkovitija membrana za uklanjanje glicerola pokazala se PT membrana pri radnom tlaku od 6 bara (6×105 Pa) koja je uklonila 38,3 % glicerola i 32,5 % etanola iz smjese. Za uklanjanje etanola iz smjese najučinkovitija je bila GK membrana također pri radnome tlaku od 6 bara koja je uklonila 57,8 % etanola iz smjese i 8,2 % glicerola.Membrane separation is a process in which the membrane separates the inlet stream on retentate (part of the inlet stream retained on the membrane) and the permeate (part of the inlet stream that passed through the membrane). Separation is based on the ability of the membrane to transport one component from the inlet stream more easily than other components based on the physical and chemical properties of the membrane and the permeating component. In this thesis a membrane ultrafiltration separation of fatty acid ethyl esters from mixture of ethanol, sunflower oil and glycerol, was conducted. Three types of polymer membranes were used: PT membrane produced by polyethersulfone with a molecular weight cut-off (MWCO) of 5000 Da and two polyamide membranes, GK with a MWCO of 3000 Da and GH with a MWCO of 2000 Da. Fatty acid ethyl ester (biodiesel) were produced by transesterification and the goal was to isolate them directly from the mixture after the reaction. The most efficient membrane for glycerol removal is PT membrane working at 6 bar (6×105 Pa). It reduced the concentration of glycerol by 38,3 % and ethanol by 32,5 % compared to starting mixture. The most efficient membrane for reducing the concentration of ethanol from the starting mixture is GK membrane under the same conditions (6 bar) and reduction of 57,8 % of ethanol and 8,2 % of glycerol, compared to concentration in starting mixture, was achieved

Plan upravljanja istraživačkim podacima

Razrađen plan upravljanja istraživačkim podacima na projektu Hrvatske zaklade za znanost "Razvoj funkcionalnih biogoriva i (bio)aditiva te ispitivanje primjenskih svojstava mješavina s mineralnim gorivima"

Plan upravljanja istraživačkim podacima

Razrađen plan upravljanja istraživačkim podacima na projektu Hrvatske zaklade za znanost "Razvoj funkcionalnih biogoriva i (bio)aditiva te ispitivanje primjenskih svojstava mješavina s mineralnim gorivima"

Biodiesel Produced from Propanol and Longer Chain Alcohols—Synthesis and Properties

Biodiesel has established itself as a renewable fuel that is used in transportation worldwide and is partially or in some cases completely replacing conventional fuels. Chemically, biodiesel is a fatty acid monoalkyl ester (FAAE). Generally, the term biodiesel refers to the fatty acid methyl or ethyl esters (FAME or FAEE). Herein, an overview of the research on the synthesis of FAAE in which the alkyl moiety is a C3+ alkyl chain (branched/unbranched) is given. In addition, a comparison of the properties of the aforementioned FAAE with each other, with FAME and FAEE, and with fuel standards is given. The length of the alkyl chain has a major influence on viscosity, while pour point temperatures are generally lower when branched alcohols are used, but the fatty acid part of the molecule also has a major influence. The development of new pathways for the synthesis of higher alcohols from biomass opens a future perspective for the production of long chain FAAE as biofuels, fuel additives, or biolubricants. Due to their properties, FAAEs produced from C3–C5 alcohols have the potential to be used as fuels, while all C3+ FAAEs can be used as valuable bioadditives, and C8+ FAAEs can be used as biolubricants and viscosity improvers

Me, the Self and I. Multiple Approaches to the Unity of the Self

International audienc