Oil methanolysis over modified CaO catalysts was studied to assess the catalytic performance and ... more Oil methanolysis over modified CaO catalysts was studied to assess the catalytic performance and to define an appropriate kinetic model. CaO was modified by commercial glycerol and a deep eutectic solvent (DES), choline chloride : glycerol (ChCl : Gly), to obtain catalytically active complexes of CaO and glycerol. The main goal was to investigate the effect of the obtained complexes on the reaction rate and fatty acid methyl ester (FAME) content and to describe the variation of the triacylglycerol (TAG) conversion degree during the reaction time. Fourier transform infrared spectroscopy (FTIR) was applied to confirm the formation of CaO complexes with glycerol or the glycerol-based DES. Different catalyst loadings (0.5, 1, and 5 % of oil weight) and methanol-to-oil molar ratios (6 : 1 and 12 : 1) were applied for investigation of the sunflower oil methanolysis at 60 oC. Two kinetic models were employed yielding the kinetic parameters, which depended on the catalyst loading and the me...
Possibilities of using waste plum stones in biodiesel production were investigated. The plum kern... more Possibilities of using waste plum stones in biodiesel production were investigated. The plum kernels were used as a source to obtain oil by the Soxhlet extraction method, while the whole plum stones, the plum stone shells that remained after the crashing, and the plum kernel cake that remained after the oil extraction, were burned off to obtain ashes. The collected ashes were characterized by elemental composition, porosity, and base strength and tested for catalytic activity in transesterification of esterified plum kernel oil. Dominant elements were potassium, calcium, and magnesium at different contents in the three obtained ashes. The most active catalyst was the plum stone shell ash, so the effect of temperature (40, 50, and 60?C) on the reaction rate was investigated. The reaction rate constant increased with the reaction temperature with the activation energy value of 58.8 kJ mol-1. In addition, the plum stone shell ash can be reused as a catalyst after recalcination.
The Canadian Journal of Chemical Engineering, 2002
... Spaces M. AleksiC', VB Veljkovik2*, Ivana Bankovi&Ilik2 ML Lazik2, and DU Sk... more ... Spaces M. AleksiC', VB Veljkovik2*, Ivana Bankovi&Ilik2 ML Lazik2, and DU Skala3 I Higher School of Agriculture, Pokuplje, dirila i Metodija 1. Yugoslavia Faculty of Technology, University of Nis, 16 000 Leskovac. Bul. ... I t 1 I PC I I PT I W - I NV I . LIQUID OlJTLEl '- AIR . INLET ...
The effects of vibration intensity, superficial gas velocity and content of solid particles on th... more The effects of vibration intensity, superficial gas velocity and content of solid particles on the volumetric oxygen mass transfer coefficient (k1a) in a 16.6 cm i.d. multiphase reciprocating plate column were strudied. The k1a increased with increasing vibration intensity and superficial gas velocity, and decreased with increasing content of solid particles. The k1a was correlated with the specific time-averaged power consumtion, the superficial gas velocity, the column diameter and the content of solid particles.
The effects of operation conditions (the vibration intensity and gas flow rate) on the gas holdup... more The effects of operation conditions (the vibration intensity and gas flow rate) on the gas holdup in a 16.6 cm i.d. two-phase reciprocating plate column (RPC) were studied. Distilled water and aqueous solutions of carboxymethyl-cellulose of different concentration were used as the liquid phase and air as the gas phase in this investigation. The gas holdup was measured after the gas flow and the reciprocating action had been stopped. An empirical correlation which correlates the gas holdup with the specific power consumption and the superficial gas velocity showed that the aeration intensity had a greater influence on the gas holdup than the intensity of agitation. Because the gas holdup was approximately the same in RPC's of different diameters, an equation relating the gas holdup with the specific power consumption and the superficial gas velocity was derived. The correlation could be used in the scaling up of reciprocating plate columns.
Gas holdup was investigated in a gas-liquid and gas-liquid-solid reciprocating plate column (RPC)... more Gas holdup was investigated in a gas-liquid and gas-liquid-solid reciprocating plate column (RPC) under various operation conditions. Aqueous carboxymethyl cellulose (sodium salt, CMC) solutions were used as the liquid phase, the solid phase was spheres placed into interplate spaces, and the gas phase was air. The gas holdup in the RPC was influenced by: the vibration intensity, i.e., the power consumption, the superficial gas velocity, the solids content and the rheological properties of the liquid phase. The gas holdup increased with increasing vibration intensity and superficial gas velocity in both the two- and three-phase system. With increasing concentration of the CMC PP 50 solution (Newtonian fluid), the gas holdup decreased, because the coalescence of the bubbles was favored by the higher liquid viscosity. In the case of the CMC PP 200 solutions (non-Newtonian liquids), the gas holdup depends on the combined influence of the rheological properties of the liquid phase, the v...
ABSTRACT h i g h l i g h t s " KOH and CaO catalyze the sunflower oil methanolysis in th... more ABSTRACT h i g h l i g h t s " KOH and CaO catalyze the sunflower oil methanolysis in the presence of cosolvents. " Tetrahydrofuran favors the triacylglycerol mass transfer by reducing drop size. " The CaO-catalyzed methanolysis is not speeded up with the use of cosolvents. a b s t r a c t Homogeneously and heterogeneously base-catalyzed sunflower oil methanolysis was investigated with-out and with the presence of the cosolvents. In the former case, KOH and tetrahydrofuran (THF) were used as a catalyst and a cosolvent, respectively, and the reaction was performed at the reaction temper-ature of 10 °C and the methanol-to-oil molar ratio of 6:1. In the latter case, CaO and various organic sol-vents such as THF, n-hexane, dioxane, diethyl ether, triethanolamine, ethyl acetate and methyl ethyl ketone were employed as a solid catalyst and a cosolvent, respectively, and the reaction was carried out at the reaction temperature of 60 °C and the methanol-to-oil molar ratio of 6:1. The rate of KOH-catalyzed sunflower oil methanolysis increased with increasing the THF concentration up to 50% of the oil mass, which was due to the self-enhancement of the interfacial area as the result of decreasing the mean drop size. No effect of THF present at the concentration of 20% on the rate of CaO-catalyzed methanolysis was observed, but at higher THF concentrations, the reaction was delayed and the final fatty acid methyl esters (FAME) yield was decreased. Of all tested cosolvents, only n-hexane and THF slightly improved the methanolysis reaction in its initial period, triethanolamine and ethyl acetate had no effect, while diethyl ether, dioxane and methyl ethyl ketone negatively influenced the reaction rate and the FAME yield.
The pressure fluctuation at the column base is confirmed to be proportional to the vibration inte... more The pressure fluctuation at the column base is confirmed to be proportional to the vibration intensity on a power of 2 in non-gassed conditions and up to a critical vibration intensity, corresponding to the dispersion resonance frequency, in gassed conditions. The power consumption is successfully correlated with the vibration intensity and the liquid holdup. The gas holdup in both mixer-settter
The kinetics of Ca(OH)(2)-catalyzed methanolysis of sunflower oil was studied at a moderate tempe... more The kinetics of Ca(OH)(2)-catalyzed methanolysis of sunflower oil was studied at a moderate temperature (60 degrees C), a methanol-to-oil molar ratio (6:1) and different catalyst amounts (from 1% to 10% based on oil weight). The methanolysis process was shown to involve the initial triglyceride (TG) mass transfer controlled region, followed by the chemical reaction controlled region in the latter period. The TG mass transfer limitation was caused by the low available active specific catalyst surface due to the high adsorbed methanol concentration. Both the TG mass transfer and chemical reaction rates increased with increasing the catalyst amount.
Oblast tehnike na koju se pronalazak odnosi Pronalazak pripada oblasti hemijske tehnologije i odn... more Oblast tehnike na koju se pronalazak odnosi Pronalazak pripada oblasti hemijske tehnologije i odnosi se na izvođenje reakcije bazno katalizovane alkoholize biljnih ulja u dvostepenom reaktorskom sistemu sa dva protočna reaktora sa vibracionom mešalicom (RVM) sa kontinualnim radom. Prema Međunarodnoj klasifikaciji patenata oznaka je: C11C 3/10. Tehnički problem Estri masnih kiselina dobijaju se katalizovanom (bazno, kiselinski ili enzimski) reakcijom alkoholize biljnih ulja i životinjskih masti, koja se može prikazati sledećom sumarnom stehiometrijskom jednačinom: U industrijskoj proizvodnji, koriste se uglavnom biljna ulja i metanol, kao reaktanti, i kalijum ili natrijum hidroksid, kao katalizator, pa je glavni proizvod smeša metil estara masnih kiselina. Smeše metil estara masnih kiselina sa osobinama koje odgovaraju standardu (na primer, JUS EN 14214, EN 14214 i ASTMPS 121-99) poznate se pod imenom biodizel, koji je alternativa dizel gorivu. Relativno mali prinos estara masnih kis...
Oil methanolysis over modified CaO catalysts was studied to assess the catalytic performance and ... more Oil methanolysis over modified CaO catalysts was studied to assess the catalytic performance and to define an appropriate kinetic model. CaO was modified by commercial glycerol and a deep eutectic solvent (DES), choline chloride : glycerol (ChCl : Gly), to obtain catalytically active complexes of CaO and glycerol. The main goal was to investigate the effect of the obtained complexes on the reaction rate and fatty acid methyl ester (FAME) content and to describe the variation of the triacylglycerol (TAG) conversion degree during the reaction time. Fourier transform infrared spectroscopy (FTIR) was applied to confirm the formation of CaO complexes with glycerol or the glycerol-based DES. Different catalyst loadings (0.5, 1, and 5 % of oil weight) and methanol-to-oil molar ratios (6 : 1 and 12 : 1) were applied for investigation of the sunflower oil methanolysis at 60 oC. Two kinetic models were employed yielding the kinetic parameters, which depended on the catalyst loading and the me...
Possibilities of using waste plum stones in biodiesel production were investigated. The plum kern... more Possibilities of using waste plum stones in biodiesel production were investigated. The plum kernels were used as a source to obtain oil by the Soxhlet extraction method, while the whole plum stones, the plum stone shells that remained after the crashing, and the plum kernel cake that remained after the oil extraction, were burned off to obtain ashes. The collected ashes were characterized by elemental composition, porosity, and base strength and tested for catalytic activity in transesterification of esterified plum kernel oil. Dominant elements were potassium, calcium, and magnesium at different contents in the three obtained ashes. The most active catalyst was the plum stone shell ash, so the effect of temperature (40, 50, and 60?C) on the reaction rate was investigated. The reaction rate constant increased with the reaction temperature with the activation energy value of 58.8 kJ mol-1. In addition, the plum stone shell ash can be reused as a catalyst after recalcination.
The Canadian Journal of Chemical Engineering, 2002
... Spaces M. AleksiC', VB Veljkovik2*, Ivana Bankovi&Ilik2 ML Lazik2, and DU Sk... more ... Spaces M. AleksiC', VB Veljkovik2*, Ivana Bankovi&Ilik2 ML Lazik2, and DU Skala3 I Higher School of Agriculture, Pokuplje, dirila i Metodija 1. Yugoslavia Faculty of Technology, University of Nis, 16 000 Leskovac. Bul. ... I t 1 I PC I I PT I W - I NV I . LIQUID OlJTLEl '- AIR . INLET ...
The effects of vibration intensity, superficial gas velocity and content of solid particles on th... more The effects of vibration intensity, superficial gas velocity and content of solid particles on the volumetric oxygen mass transfer coefficient (k1a) in a 16.6 cm i.d. multiphase reciprocating plate column were strudied. The k1a increased with increasing vibration intensity and superficial gas velocity, and decreased with increasing content of solid particles. The k1a was correlated with the specific time-averaged power consumtion, the superficial gas velocity, the column diameter and the content of solid particles.
The effects of operation conditions (the vibration intensity and gas flow rate) on the gas holdup... more The effects of operation conditions (the vibration intensity and gas flow rate) on the gas holdup in a 16.6 cm i.d. two-phase reciprocating plate column (RPC) were studied. Distilled water and aqueous solutions of carboxymethyl-cellulose of different concentration were used as the liquid phase and air as the gas phase in this investigation. The gas holdup was measured after the gas flow and the reciprocating action had been stopped. An empirical correlation which correlates the gas holdup with the specific power consumption and the superficial gas velocity showed that the aeration intensity had a greater influence on the gas holdup than the intensity of agitation. Because the gas holdup was approximately the same in RPC's of different diameters, an equation relating the gas holdup with the specific power consumption and the superficial gas velocity was derived. The correlation could be used in the scaling up of reciprocating plate columns.
Gas holdup was investigated in a gas-liquid and gas-liquid-solid reciprocating plate column (RPC)... more Gas holdup was investigated in a gas-liquid and gas-liquid-solid reciprocating plate column (RPC) under various operation conditions. Aqueous carboxymethyl cellulose (sodium salt, CMC) solutions were used as the liquid phase, the solid phase was spheres placed into interplate spaces, and the gas phase was air. The gas holdup in the RPC was influenced by: the vibration intensity, i.e., the power consumption, the superficial gas velocity, the solids content and the rheological properties of the liquid phase. The gas holdup increased with increasing vibration intensity and superficial gas velocity in both the two- and three-phase system. With increasing concentration of the CMC PP 50 solution (Newtonian fluid), the gas holdup decreased, because the coalescence of the bubbles was favored by the higher liquid viscosity. In the case of the CMC PP 200 solutions (non-Newtonian liquids), the gas holdup depends on the combined influence of the rheological properties of the liquid phase, the v...
ABSTRACT h i g h l i g h t s " KOH and CaO catalyze the sunflower oil methanolysis in th... more ABSTRACT h i g h l i g h t s " KOH and CaO catalyze the sunflower oil methanolysis in the presence of cosolvents. " Tetrahydrofuran favors the triacylglycerol mass transfer by reducing drop size. " The CaO-catalyzed methanolysis is not speeded up with the use of cosolvents. a b s t r a c t Homogeneously and heterogeneously base-catalyzed sunflower oil methanolysis was investigated with-out and with the presence of the cosolvents. In the former case, KOH and tetrahydrofuran (THF) were used as a catalyst and a cosolvent, respectively, and the reaction was performed at the reaction temper-ature of 10 °C and the methanol-to-oil molar ratio of 6:1. In the latter case, CaO and various organic sol-vents such as THF, n-hexane, dioxane, diethyl ether, triethanolamine, ethyl acetate and methyl ethyl ketone were employed as a solid catalyst and a cosolvent, respectively, and the reaction was carried out at the reaction temperature of 60 °C and the methanol-to-oil molar ratio of 6:1. The rate of KOH-catalyzed sunflower oil methanolysis increased with increasing the THF concentration up to 50% of the oil mass, which was due to the self-enhancement of the interfacial area as the result of decreasing the mean drop size. No effect of THF present at the concentration of 20% on the rate of CaO-catalyzed methanolysis was observed, but at higher THF concentrations, the reaction was delayed and the final fatty acid methyl esters (FAME) yield was decreased. Of all tested cosolvents, only n-hexane and THF slightly improved the methanolysis reaction in its initial period, triethanolamine and ethyl acetate had no effect, while diethyl ether, dioxane and methyl ethyl ketone negatively influenced the reaction rate and the FAME yield.
The pressure fluctuation at the column base is confirmed to be proportional to the vibration inte... more The pressure fluctuation at the column base is confirmed to be proportional to the vibration intensity on a power of 2 in non-gassed conditions and up to a critical vibration intensity, corresponding to the dispersion resonance frequency, in gassed conditions. The power consumption is successfully correlated with the vibration intensity and the liquid holdup. The gas holdup in both mixer-settter
The kinetics of Ca(OH)(2)-catalyzed methanolysis of sunflower oil was studied at a moderate tempe... more The kinetics of Ca(OH)(2)-catalyzed methanolysis of sunflower oil was studied at a moderate temperature (60 degrees C), a methanol-to-oil molar ratio (6:1) and different catalyst amounts (from 1% to 10% based on oil weight). The methanolysis process was shown to involve the initial triglyceride (TG) mass transfer controlled region, followed by the chemical reaction controlled region in the latter period. The TG mass transfer limitation was caused by the low available active specific catalyst surface due to the high adsorbed methanol concentration. Both the TG mass transfer and chemical reaction rates increased with increasing the catalyst amount.
Oblast tehnike na koju se pronalazak odnosi Pronalazak pripada oblasti hemijske tehnologije i odn... more Oblast tehnike na koju se pronalazak odnosi Pronalazak pripada oblasti hemijske tehnologije i odnosi se na izvođenje reakcije bazno katalizovane alkoholize biljnih ulja u dvostepenom reaktorskom sistemu sa dva protočna reaktora sa vibracionom mešalicom (RVM) sa kontinualnim radom. Prema Međunarodnoj klasifikaciji patenata oznaka je: C11C 3/10. Tehnički problem Estri masnih kiselina dobijaju se katalizovanom (bazno, kiselinski ili enzimski) reakcijom alkoholize biljnih ulja i životinjskih masti, koja se može prikazati sledećom sumarnom stehiometrijskom jednačinom: U industrijskoj proizvodnji, koriste se uglavnom biljna ulja i metanol, kao reaktanti, i kalijum ili natrijum hidroksid, kao katalizator, pa je glavni proizvod smeša metil estara masnih kiselina. Smeše metil estara masnih kiselina sa osobinama koje odgovaraju standardu (na primer, JUS EN 14214, EN 14214 i ASTMPS 121-99) poznate se pod imenom biodizel, koji je alternativa dizel gorivu. Relativno mali prinos estara masnih kis...
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