Kemija u industriji : Časopis kemičara i kemijskih inženjera Hrvatske, Sep 7, 2009
S l i k a 1 -Shema umreÞavanja stirena i nezasiaeenog poliestera F i g. 1 -Curing scheme of styre... more S l i k a 1 -Shema umreÞavanja stirena i nezasiaeenog poliestera F i g. 1 -Curing scheme of styrene and unsaturated polyester
Chemical and Biochemical Engineering Quarterly, Sep 30, 2010
Adsorptive desulfurization of diesel fuel was investigated applying two Design of Experiments (DO... more Adsorptive desulfurization of diesel fuel was investigated applying two Design of Experiments (DOE) methods. The experiments were carried out in a batch adsorption system using Chemviron Carbon SOLCARB TM C3 activated carbon as adsorbent. The first DOE method employed was a full factorial with three factors on two levels and five center points, and the second was Box-Behneken design with the same three factors but on three levels. The effects of individual factors and their interactions on sulfur concentration and sorption capacity were determined, and statistical models of the process developed. The first-order models predict the behavior of the system rather well but significant curvature was detected. Subsequently developed second-order models were able to give reasonably well descriptions of the system. The lowest achieved output sulfur concentration was 7.6 mg kg-1 with relatively low sorption capacity of 0.0861 mg g-1 .
U ovom je radu opisana i eksperimentalno ispitana metoda smanjenja kolicine sumporovih spojeva u ... more U ovom je radu opisana i eksperimentalno ispitana metoda smanjenja kolicine sumporovih spojeva u FCC benzinu procesom kapljevinske ekstrakcije. Proces se provodio saržno, a odabranim eksperimentom ispitan je utjecaj procesnih parametara (omjer otapalo/sirovina, temperatura, vrijeme trajanja procesa i okretaji mijesala) na ucinkovitost uklanjanja sumporovih spojeva uz sulfolan kao ekstraktivno sredstvo. Za analizu eksperimentalno dobivenih podataka primijenila se statisticka metoda planiranja eksperimenata. Istražen je utjecaj 4 faktora, svaki na 2 nivoa. Opisani dizajn naziva se 2^4 faktorski plan, ukljucuje 16 kombinacija i sadrži 15 stupnjeva slobode. 4 stupnja slobode su povezana s glavnim faktorima, a 11 s međudjelovanjima.
Alternative processes for desulfurization of transportation fuels are receiving increasing attent... more Alternative processes for desulfurization of transportation fuels are receiving increasing attention due to increasingly stringent regulations and fuel specifications in many countries for environmental protection purposes. Adsorption technology has been proposed for the removal of sulfur compounds in fuels. Compared to the hydrodesulfurization process, the adsorptive removal of sulfur compounds seems very promising since adsorption can be accomplished at low temperature and pressure, and the sulfur in fuels can be removed to a very low level. Design of Experiments, DOE, is a powerful statistical tool for exploring new processes or gaining detailed comprehension of existing ones, and then optimizing those processes. In this work organic sulfur compounds were removed from diesel fuel by selective adsorption with different types of commercial activated carbons. Adsorption was carried out in batch adsorbers. The model of the process was developed by way of two-level fractional factorial experimental design with four process parameters. Total sulfur content was measured with wave dispersive x-ray fluorescent spectrometer. Activated carbon Chemviron Carbon SOLCARB™ C3 has given the best desulfurization results. The process is well described within the experimental region by the developed model which was statistically validated.
International Journal of Chemical Reactor Engineering, Nov 1, 2022
The aim of this study was to develop a new rotating photocatalytic reactor operating in recircula... more The aim of this study was to develop a new rotating photocatalytic reactor operating in recirculation mode with light sources placed outside the photoreactor vessel. The photoreactor with cylindrical geometry was equipped with four artificial lamps used to simulate solar irradiation (2.4% UVB and 12% UVA; 300–700 nm). The photocatalyst was immobilized on abrasive material used as a support and placed on the central (inner) photoreactor tube, which was connected to a power-driven shaft that allowed rotation at a desired speed. A suitable modification of the commercial TiO2 P25 photocatalyst was carried out to reduce its band gap energy and electron-hole recombination and to extend the visible light response range of TiO2. The main task of this research was to apply the basic principles of process intensification methodology, i.e. to explore the influence of rotational hydrodynamics, which allows good access of reactants to the photocatalyst surface, good irradiation of the photocatalytic surface and reduction of mass transfer resistance, leading to increased process efficiency. The homemade photoreactor was used for the photocatalytic degradation of one of the major types of neonicotinoid insecticides, acetamiprid. The influence of various working conditions, such as initial solution pH, rotation speed, recirculation flow rate and initial concentration of acetamiprid on the photocatalytic degradation process was investigated. The optimum degradation conditions were found at a recirculation flow rate of 200 cm3 min−1 and a rotation speed of 200 rpm, indicating that the mass transfer process strongly contributes to the photocatalytic degradation rate at the conditions used in this study. The results obtained during the photocatalytic degradation of acetamiprid in a rotating photoreactor were compared with those obtained under similar operating conditions in a flat-plate photoreactor, and the corresponding conclusions were drawn based on the performed kinetic analysis.
Catalytic decomposition of NO over Cu/ZSM-5 catalysts has been carried out in a tubular fixed-bed... more Catalytic decomposition of NO over Cu/ZSM-5 catalysts has been carried out in a tubular fixed-bed reactor at atmospheric pressure. The influence of the catalyst composition on its physical-chemical and catalytic properties has been investigated. An optimal content of copper at wich Cu/ZSM-5 catalyst demonstrated maximum activity has been established. ft has been found that catalyst activity increased with the increase in Si/Al ratio or with the decrease in aluminium content over zeolite. The addition of binders, such as MgO, ZnO, AlF 3 and Na- silicate changed physical properties of the catalyst and at the same time facilitated shaping of the catalyst during the preparation step.
ABSTRACT The intensity of the thermal oxidation has been followed through kinetic parameters. In ... more ABSTRACT The intensity of the thermal oxidation has been followed through kinetic parameters. In styrene/butadiene copolymers, soft polybutadiene phase (PB) and hard polystyrene phase (PS) have different sensibilities to thermal degradation. The thermal oxidative stability of high-impact polystyrene (PS-HI), styrene/butadiene/styrene block copolymers (SBS), and PS-HI + SBS blends were investigated by isothermal DSC analysis. The kinetic parameters of the thermal oxidative degradative process: the reaction rate constants, the reaction orders and the activation energies have been determined. The total area under the exothermic curve was used to calculate the isothermal heats of degradation. The conversion (α) and the rate of the thermal oxidative degradation (dα/dt) have been derivated. The experimental data have been tested with a kinetic model for autocatalytic reactions: dα/dt = k αm (1 − α)n. Activation energies have been determined from the Arrhenius equation and the order of the thermal oxidative stability evaluated. The extent of agreement of the experimental data with the autocatalytic model is discussed.
U ovome radu analiziran je prijenos topline i kinetika reakcije ocvrscivanja nezasicene poliester... more U ovome radu analiziran je prijenos topline i kinetika reakcije ocvrscivanja nezasicene poliesterske smole sa i bez punila grijanjem kalupa vrucim zrakom. Kinetika reakcije ocvrscivanja određena je diferencijalnom pretražnom kalorimetrijom (DSC), a prijenos topline kroz kalup plocastog oblika mjerenjem temperature u sredistu uzorka. Izveden je matematicki model reakcije ocvrscivanja koji se sastoji od sustava parcijalnih diferencijalnih jednadžbi, koje opisuju bilancu tvari i topline kao i reaktorski model za kotlasti reaktor i kineticki model autokataliticke reakcije. Prijenos topline sa zraka na stijenku klupa odigrava se konvekcijom, a kroz uzorak unutar kalupa vođenjem sto je definirano u modelu kroz rubne uvijete i bilancu topline. Dani model rijesen je uz definirane rubne uvjete numerickom metodom linija za rjesavanje sustava PDJ uz istovremenu procjenu parametara modela. Matematicki model dan je sljedecim jednadžbama: (1) (2) (3) Na temelju provedenih eksperimenata u kalupu i provedene matematicke analize dobivena je potpunija slika reakcije ocvrscivanja u modelnim kalupima, a stecene spoznaje mogu se primijeniti pri izradi konstrukcijskih materijala na bazi nezasicenih poliesterskih smola kao i pri modeliranju proizvodnih kalupa.
U elaboratu opisana je mogucnost zamjene postojeceg kloriranog platinskog katalizatora sa cirkoni... more U elaboratu opisana je mogucnost zamjene postojeceg kloriranog platinskog katalizatora sa cirkonij sulfat katalizatorom nove generacije, na postrojenju za niskotemperaturnu izomerizaciju u Rafineriji nafte Rijeka. Opisan je mehanizam djelovanja novog katalizatora, te je detaljno razrađeno i opisano pilot postrojenje koje ce se izgraditi u svrhu ispitivanja optimalnih radnih uvjeta procesa izomerizacije (tlak, temperatura, protok sirovine, omjer H2/HC) u skladu sa uputama vlasnika licence katalizatora.
Kemija u industriji : Časopis kemičara i kemijskih inženjera Hrvatske, Sep 7, 2009
S l i k a 1 -Shema umreÞavanja stirena i nezasiaeenog poliestera F i g. 1 -Curing scheme of styre... more S l i k a 1 -Shema umreÞavanja stirena i nezasiaeenog poliestera F i g. 1 -Curing scheme of styrene and unsaturated polyester
Chemical and Biochemical Engineering Quarterly, Sep 30, 2010
Adsorptive desulfurization of diesel fuel was investigated applying two Design of Experiments (DO... more Adsorptive desulfurization of diesel fuel was investigated applying two Design of Experiments (DOE) methods. The experiments were carried out in a batch adsorption system using Chemviron Carbon SOLCARB TM C3 activated carbon as adsorbent. The first DOE method employed was a full factorial with three factors on two levels and five center points, and the second was Box-Behneken design with the same three factors but on three levels. The effects of individual factors and their interactions on sulfur concentration and sorption capacity were determined, and statistical models of the process developed. The first-order models predict the behavior of the system rather well but significant curvature was detected. Subsequently developed second-order models were able to give reasonably well descriptions of the system. The lowest achieved output sulfur concentration was 7.6 mg kg-1 with relatively low sorption capacity of 0.0861 mg g-1 .
U ovom je radu opisana i eksperimentalno ispitana metoda smanjenja kolicine sumporovih spojeva u ... more U ovom je radu opisana i eksperimentalno ispitana metoda smanjenja kolicine sumporovih spojeva u FCC benzinu procesom kapljevinske ekstrakcije. Proces se provodio saržno, a odabranim eksperimentom ispitan je utjecaj procesnih parametara (omjer otapalo/sirovina, temperatura, vrijeme trajanja procesa i okretaji mijesala) na ucinkovitost uklanjanja sumporovih spojeva uz sulfolan kao ekstraktivno sredstvo. Za analizu eksperimentalno dobivenih podataka primijenila se statisticka metoda planiranja eksperimenata. Istražen je utjecaj 4 faktora, svaki na 2 nivoa. Opisani dizajn naziva se 2^4 faktorski plan, ukljucuje 16 kombinacija i sadrži 15 stupnjeva slobode. 4 stupnja slobode su povezana s glavnim faktorima, a 11 s međudjelovanjima.
Alternative processes for desulfurization of transportation fuels are receiving increasing attent... more Alternative processes for desulfurization of transportation fuels are receiving increasing attention due to increasingly stringent regulations and fuel specifications in many countries for environmental protection purposes. Adsorption technology has been proposed for the removal of sulfur compounds in fuels. Compared to the hydrodesulfurization process, the adsorptive removal of sulfur compounds seems very promising since adsorption can be accomplished at low temperature and pressure, and the sulfur in fuels can be removed to a very low level. Design of Experiments, DOE, is a powerful statistical tool for exploring new processes or gaining detailed comprehension of existing ones, and then optimizing those processes. In this work organic sulfur compounds were removed from diesel fuel by selective adsorption with different types of commercial activated carbons. Adsorption was carried out in batch adsorbers. The model of the process was developed by way of two-level fractional factorial experimental design with four process parameters. Total sulfur content was measured with wave dispersive x-ray fluorescent spectrometer. Activated carbon Chemviron Carbon SOLCARB™ C3 has given the best desulfurization results. The process is well described within the experimental region by the developed model which was statistically validated.
International Journal of Chemical Reactor Engineering, Nov 1, 2022
The aim of this study was to develop a new rotating photocatalytic reactor operating in recircula... more The aim of this study was to develop a new rotating photocatalytic reactor operating in recirculation mode with light sources placed outside the photoreactor vessel. The photoreactor with cylindrical geometry was equipped with four artificial lamps used to simulate solar irradiation (2.4% UVB and 12% UVA; 300–700 nm). The photocatalyst was immobilized on abrasive material used as a support and placed on the central (inner) photoreactor tube, which was connected to a power-driven shaft that allowed rotation at a desired speed. A suitable modification of the commercial TiO2 P25 photocatalyst was carried out to reduce its band gap energy and electron-hole recombination and to extend the visible light response range of TiO2. The main task of this research was to apply the basic principles of process intensification methodology, i.e. to explore the influence of rotational hydrodynamics, which allows good access of reactants to the photocatalyst surface, good irradiation of the photocatalytic surface and reduction of mass transfer resistance, leading to increased process efficiency. The homemade photoreactor was used for the photocatalytic degradation of one of the major types of neonicotinoid insecticides, acetamiprid. The influence of various working conditions, such as initial solution pH, rotation speed, recirculation flow rate and initial concentration of acetamiprid on the photocatalytic degradation process was investigated. The optimum degradation conditions were found at a recirculation flow rate of 200 cm3 min−1 and a rotation speed of 200 rpm, indicating that the mass transfer process strongly contributes to the photocatalytic degradation rate at the conditions used in this study. The results obtained during the photocatalytic degradation of acetamiprid in a rotating photoreactor were compared with those obtained under similar operating conditions in a flat-plate photoreactor, and the corresponding conclusions were drawn based on the performed kinetic analysis.
Catalytic decomposition of NO over Cu/ZSM-5 catalysts has been carried out in a tubular fixed-bed... more Catalytic decomposition of NO over Cu/ZSM-5 catalysts has been carried out in a tubular fixed-bed reactor at atmospheric pressure. The influence of the catalyst composition on its physical-chemical and catalytic properties has been investigated. An optimal content of copper at wich Cu/ZSM-5 catalyst demonstrated maximum activity has been established. ft has been found that catalyst activity increased with the increase in Si/Al ratio or with the decrease in aluminium content over zeolite. The addition of binders, such as MgO, ZnO, AlF 3 and Na- silicate changed physical properties of the catalyst and at the same time facilitated shaping of the catalyst during the preparation step.
ABSTRACT The intensity of the thermal oxidation has been followed through kinetic parameters. In ... more ABSTRACT The intensity of the thermal oxidation has been followed through kinetic parameters. In styrene/butadiene copolymers, soft polybutadiene phase (PB) and hard polystyrene phase (PS) have different sensibilities to thermal degradation. The thermal oxidative stability of high-impact polystyrene (PS-HI), styrene/butadiene/styrene block copolymers (SBS), and PS-HI + SBS blends were investigated by isothermal DSC analysis. The kinetic parameters of the thermal oxidative degradative process: the reaction rate constants, the reaction orders and the activation energies have been determined. The total area under the exothermic curve was used to calculate the isothermal heats of degradation. The conversion (α) and the rate of the thermal oxidative degradation (dα/dt) have been derivated. The experimental data have been tested with a kinetic model for autocatalytic reactions: dα/dt = k αm (1 − α)n. Activation energies have been determined from the Arrhenius equation and the order of the thermal oxidative stability evaluated. The extent of agreement of the experimental data with the autocatalytic model is discussed.
U ovome radu analiziran je prijenos topline i kinetika reakcije ocvrscivanja nezasicene poliester... more U ovome radu analiziran je prijenos topline i kinetika reakcije ocvrscivanja nezasicene poliesterske smole sa i bez punila grijanjem kalupa vrucim zrakom. Kinetika reakcije ocvrscivanja određena je diferencijalnom pretražnom kalorimetrijom (DSC), a prijenos topline kroz kalup plocastog oblika mjerenjem temperature u sredistu uzorka. Izveden je matematicki model reakcije ocvrscivanja koji se sastoji od sustava parcijalnih diferencijalnih jednadžbi, koje opisuju bilancu tvari i topline kao i reaktorski model za kotlasti reaktor i kineticki model autokataliticke reakcije. Prijenos topline sa zraka na stijenku klupa odigrava se konvekcijom, a kroz uzorak unutar kalupa vođenjem sto je definirano u modelu kroz rubne uvijete i bilancu topline. Dani model rijesen je uz definirane rubne uvjete numerickom metodom linija za rjesavanje sustava PDJ uz istovremenu procjenu parametara modela. Matematicki model dan je sljedecim jednadžbama: (1) (2) (3) Na temelju provedenih eksperimenata u kalupu i provedene matematicke analize dobivena je potpunija slika reakcije ocvrscivanja u modelnim kalupima, a stecene spoznaje mogu se primijeniti pri izradi konstrukcijskih materijala na bazi nezasicenih poliesterskih smola kao i pri modeliranju proizvodnih kalupa.
U elaboratu opisana je mogucnost zamjene postojeceg kloriranog platinskog katalizatora sa cirkoni... more U elaboratu opisana je mogucnost zamjene postojeceg kloriranog platinskog katalizatora sa cirkonij sulfat katalizatorom nove generacije, na postrojenju za niskotemperaturnu izomerizaciju u Rafineriji nafte Rijeka. Opisan je mehanizam djelovanja novog katalizatora, te je detaljno razrađeno i opisano pilot postrojenje koje ce se izgraditi u svrhu ispitivanja optimalnih radnih uvjeta procesa izomerizacije (tlak, temperatura, protok sirovine, omjer H2/HC) u skladu sa uputama vlasnika licence katalizatora.
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