TY  - JOUR
AU  - Pavlović, Marko
AU  - Lubura, Jelena
AU  - Pezo, Lato
AU  - Pezo, Milada
AU  - Bera, Oskar
AU  - Kojić, Predrag
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11220
AB  - The purpose of the study was to identify and predict the optimized parameters for phosphoric acid production. This involved modeling the crystal reactor, UCEGO filter (as a detailed model of the filter is not available in Aspen Plus or other simulation software), and acid separator using Sci-Lab to develop Cape-Open models. The simulation was conducted using Aspen Plus and involved analyzing 10 different phosphates with varying qualities and fractions of P2O5 and other minerals. After a successful simulation, a sensitivity analysis was conducted by varying parameters such as capacity, filter speed, vacuum, particle size, water temperature for washing the filtration cake, flow of recycled acid and strong acid from the separator below the filter, flow of slurry to reactor 1, temperature in reactors, and flow of H2SO4, resulting in nearly one million combinations. To create an algorithm for predicting process parameters and the maximal extent of recovering H3PO4 from slurry, ANN models were developed with a determination coefficient of 99%. Multi-objective optimization was then performed using a genetic algorithm to find the most suitable parameters that would lead to a higher reaction degree (96–97%) and quantity of separated H3PO4 and lower losses of gypsum. The results indicated that it is possible to predict the influence of process parameters on the quality of produced acid and minimize losses during production. The developed model was confirmed to be viable when compared to results found in the literature.
T2  - Processes
T1  - A Novel Hybrid Approach for Modeling and Optimisation of Phosphoric Acid Production through the Integration of AspenTech, SciLab Unit Operation, Artificial Neural Networks and Genetic Algorithm
VL  - 11
IS  - 6
SP  - 1753
DO  - 10.3390/pr11061753
ER  - 

@article{
author = "Pavlović, Marko and Lubura, Jelena and Pezo, Lato and Pezo, Milada and Bera, Oskar and Kojić, Predrag",
year = "2023",
abstract = "The purpose of the study was to identify and predict the optimized parameters for phosphoric acid production. This involved modeling the crystal reactor, UCEGO filter (as a detailed model of the filter is not available in Aspen Plus or other simulation software), and acid separator using Sci-Lab to develop Cape-Open models. The simulation was conducted using Aspen Plus and involved analyzing 10 different phosphates with varying qualities and fractions of P2O5 and other minerals. After a successful simulation, a sensitivity analysis was conducted by varying parameters such as capacity, filter speed, vacuum, particle size, water temperature for washing the filtration cake, flow of recycled acid and strong acid from the separator below the filter, flow of slurry to reactor 1, temperature in reactors, and flow of H2SO4, resulting in nearly one million combinations. To create an algorithm for predicting process parameters and the maximal extent of recovering H3PO4 from slurry, ANN models were developed with a determination coefficient of 99%. Multi-objective optimization was then performed using a genetic algorithm to find the most suitable parameters that would lead to a higher reaction degree (96–97%) and quantity of separated H3PO4 and lower losses of gypsum. The results indicated that it is possible to predict the influence of process parameters on the quality of produced acid and minimize losses during production. The developed model was confirmed to be viable when compared to results found in the literature.",
journal = "Processes",
title = "A Novel Hybrid Approach for Modeling and Optimisation of Phosphoric Acid Production through the Integration of AspenTech, SciLab Unit Operation, Artificial Neural Networks and Genetic Algorithm",
volume = "11",
number = "6",
pages = "1753",
doi = "10.3390/pr11061753"
}

Pavlović, M., Lubura, J., Pezo, L., Pezo, M., Bera, O.,& Kojić, P.. (2023). A Novel Hybrid Approach for Modeling and Optimisation of Phosphoric Acid Production through the Integration of AspenTech, SciLab Unit Operation, Artificial Neural Networks and Genetic Algorithm. in Processes, 11(6), 1753.
https://doi.org/10.3390/pr11061753

Pavlović M, Lubura J, Pezo L, Pezo M, Bera O, Kojić P. A Novel Hybrid Approach for Modeling and Optimisation of Phosphoric Acid Production through the Integration of AspenTech, SciLab Unit Operation, Artificial Neural Networks and Genetic Algorithm. in Processes. 2023;11(6):1753.
doi:10.3390/pr11061753 .

Pavlović, Marko, Lubura, Jelena, Pezo, Lato, Pezo, Milada, Bera, Oskar, Kojić, Predrag, "A Novel Hybrid Approach for Modeling and Optimisation of Phosphoric Acid Production through the Integration of AspenTech, SciLab Unit Operation, Artificial Neural Networks and Genetic Algorithm" in Processes, 11, no. 6 (2023):1753,
https://doi.org/10.3390/pr11061753 . .

TY  - JOUR
AU  - Kojić, Predrag
AU  - Kojić, Jovana
AU  - Pezo, Milada L.
AU  - Krulj, Jelena
AU  - Pezo, Lato
AU  - Mirkov, Nikola S.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10294
AB  - The objective of this study was to investigate the hydrodynamics and the gas-liquid mass transfer coefficient of an external-loop airlift reactor (ELAR). The ELAR was operated in three cases: different inlet velocities of fluids, different alcohols solutions (water, 0.5% methanol, 0.5% ethanol, 0.5% propanol and 0.5% butanol) and different concentration of methanol in solutions (0%, 0.5%, 1%, 2% and 5%). The influence of superficial gas velocity and various diluted alcohol solutions on hydrodynamics and the gas-liquid mass transfer coefficient of the ELAR was studied. Experimentally, the gas hold-up, liquid velocities and volumetric mass transfer coefficient values in the riser and the downcomer were obtained from the literature source. A computational fluid dynamics (CFD) model was developed, based on two-phase flow, investigating different liquids regarding surface tension, assuming the ideal gas flow, applying the finite volume method and Eulerian-Eulerian model. The volumetric mass transfer coefficient was determined using the CFD and artificial neural network model. The effects of liquid parameters and gas velocity on the characteristics of the gas-liquid mass transfer were simulated. These models were compared with the appropriate experimental results. The CFD model successfully simulates the influence of different alcohols regarding the number of C-atoms on hydrodynamics and mass transfer.
T2  - Chemical Industry and Chemical Engineering Quarterly / CICEQ
T1  - Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor
VL  - 28
IS  - 3
SP  - 225
EP  - 235
DO  - 10.2298/CICEQ210522034K
ER  - 

@article{
author = "Kojić, Predrag and Kojić, Jovana and Pezo, Milada L. and Krulj, Jelena and Pezo, Lato and Mirkov, Nikola S.",
year = "2022",
abstract = "The objective of this study was to investigate the hydrodynamics and the gas-liquid mass transfer coefficient of an external-loop airlift reactor (ELAR). The ELAR was operated in three cases: different inlet velocities of fluids, different alcohols solutions (water, 0.5% methanol, 0.5% ethanol, 0.5% propanol and 0.5% butanol) and different concentration of methanol in solutions (0%, 0.5%, 1%, 2% and 5%). The influence of superficial gas velocity and various diluted alcohol solutions on hydrodynamics and the gas-liquid mass transfer coefficient of the ELAR was studied. Experimentally, the gas hold-up, liquid velocities and volumetric mass transfer coefficient values in the riser and the downcomer were obtained from the literature source. A computational fluid dynamics (CFD) model was developed, based on two-phase flow, investigating different liquids regarding surface tension, assuming the ideal gas flow, applying the finite volume method and Eulerian-Eulerian model. The volumetric mass transfer coefficient was determined using the CFD and artificial neural network model. The effects of liquid parameters and gas velocity on the characteristics of the gas-liquid mass transfer were simulated. These models were compared with the appropriate experimental results. The CFD model successfully simulates the influence of different alcohols regarding the number of C-atoms on hydrodynamics and mass transfer.",
journal = "Chemical Industry and Chemical Engineering Quarterly / CICEQ",
title = "Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor",
volume = "28",
number = "3",
pages = "225-235",
doi = "10.2298/CICEQ210522034K"
}

Kojić, P., Kojić, J., Pezo, M. L., Krulj, J., Pezo, L.,& Mirkov, N. S.. (2022). Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor. in Chemical Industry and Chemical Engineering Quarterly / CICEQ, 28(3), 225-235.
https://doi.org/10.2298/CICEQ210522034K

Kojić P, Kojić J, Pezo ML, Krulj J, Pezo L, Mirkov NS. Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor. in Chemical Industry and Chemical Engineering Quarterly / CICEQ. 2022;28(3):225-235.
doi:10.2298/CICEQ210522034K .

Kojić, Predrag, Kojić, Jovana, Pezo, Milada L., Krulj, Jelena, Pezo, Lato, Mirkov, Nikola S., "Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor" in Chemical Industry and Chemical Engineering Quarterly / CICEQ, 28, no. 3 (2022):225-235,
https://doi.org/10.2298/CICEQ210522034K . .

TY  - JOUR
AU  - Pezo, Lato
AU  - Pezo, Milada L.
AU  - Terzić, Anja
AU  - Jovanović, Aca P.
AU  - Lončar, Biljana
AU  - Govedarica, Dragan
AU  - Kojić, Predrag
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10037
AB  - The numerical model of the granular flow within an aggregate mixture, conducted in the vertical static and/or the conveyor blender, was explored using the discrete element method (DEM) approach. The blending quality of limestone fine aggregate fractions binary mixture for application in self-compacting concrete was studied. The potential of augmenting the conveyor mixer working efficiency by joining its operation to a Komax-type vertical static mixer, to increase the blending conduct was investigated. In addition the impact of the feed height on the flow field in the cone-shaped conveyor mixer was examined using the DEM simulation. Applying the numerical approach enabled a deeper insight into the quality of blending actions, while the relative standard deviation criteria ranked the uniformity of the mixture. The primary objective of this investigation was to examine the behavior of mixture for two types of blenders and to estimate the combined blending action of these two mixers, to explore the potential to augment the homogeneity of the aggregate fractions binary mixture, i.e., mixing quality, reduce the blending time and to abbreviate the energy-consuming.
T2  - Processes
T1  - Experimental and Discrete Element Model Investigation of Limestone Aggregate Blending Process in Vertical Static and/or Conveyor Mixer for Application in the Concrete Mixture
VL  - 9
IS  - 11
SP  - 1991
DO  - 10.3390/pr9111991
ER  - 

@article{
author = "Pezo, Lato and Pezo, Milada L. and Terzić, Anja and Jovanović, Aca P. and Lončar, Biljana and Govedarica, Dragan and Kojić, Predrag",
year = "2021",
abstract = "The numerical model of the granular flow within an aggregate mixture, conducted in the vertical static and/or the conveyor blender, was explored using the discrete element method (DEM) approach. The blending quality of limestone fine aggregate fractions binary mixture for application in self-compacting concrete was studied. The potential of augmenting the conveyor mixer working efficiency by joining its operation to a Komax-type vertical static mixer, to increase the blending conduct was investigated. In addition the impact of the feed height on the flow field in the cone-shaped conveyor mixer was examined using the DEM simulation. Applying the numerical approach enabled a deeper insight into the quality of blending actions, while the relative standard deviation criteria ranked the uniformity of the mixture. The primary objective of this investigation was to examine the behavior of mixture for two types of blenders and to estimate the combined blending action of these two mixers, to explore the potential to augment the homogeneity of the aggregate fractions binary mixture, i.e., mixing quality, reduce the blending time and to abbreviate the energy-consuming.",
journal = "Processes",
title = "Experimental and Discrete Element Model Investigation of Limestone Aggregate Blending Process in Vertical Static and/or Conveyor Mixer for Application in the Concrete Mixture",
volume = "9",
number = "11",
pages = "1991",
doi = "10.3390/pr9111991"
}

Pezo, L., Pezo, M. L., Terzić, A., Jovanović, A. P., Lončar, B., Govedarica, D.,& Kojić, P.. (2021). Experimental and Discrete Element Model Investigation of Limestone Aggregate Blending Process in Vertical Static and/or Conveyor Mixer for Application in the Concrete Mixture. in Processes, 9(11), 1991.
https://doi.org/10.3390/pr9111991

Pezo L, Pezo ML, Terzić A, Jovanović AP, Lončar B, Govedarica D, Kojić P. Experimental and Discrete Element Model Investigation of Limestone Aggregate Blending Process in Vertical Static and/or Conveyor Mixer for Application in the Concrete Mixture. in Processes. 2021;9(11):1991.
doi:10.3390/pr9111991 .

Pezo, Lato, Pezo, Milada L., Terzić, Anja, Jovanović, Aca P., Lončar, Biljana, Govedarica, Dragan, Kojić, Predrag, "Experimental and Discrete Element Model Investigation of Limestone Aggregate Blending Process in Vertical Static and/or Conveyor Mixer for Application in the Concrete Mixture" in Processes, 9, no. 11 (2021):1991,
https://doi.org/10.3390/pr9111991 . .

TY  - JOUR
AU  - Pezo, Lato
AU  - Pezo, Milada L.
AU  - Banjac, Vojislav
AU  - Jovanović, Aca
AU  - Krulj, Jelena
AU  - Kojić, Jovana
AU  - Kojić, Predrag
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9118
AB  - The mixing quality of the pigeon diet mix was studied after the mixing in the Ross-type static mixer (pre-mixer) and the vertical feed mixer (final mixer in the line). Three different experiments were performed: firstly, the possibilities of static mixer were investigated, secondly the blending performance of the vertical feed mixer, and the combination of these approaches in the third experiment. The Discrete Element Method was used in numerical modelling of granular flow in the pre-mixer and the vertical feed mixer, to predict the inter-particle mixing quality, and the results of the mixing. The results of the model were compared with appropriate experiments. The main goal was to foresee the behaviour of mixture in two type of mixers and to evaluate the combined mixing action of these two mixers, in order to explore the possibilities to increase the mixing quality, shorten the mixing time and to reduce the energy consumption.
T2  - Powder Technology
T1  - Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach
VL  - 375
SP  - 20
EP  - 27
DO  - 10.1016/j.powtec.2020.07.104
ER  - 

@article{
author = "Pezo, Lato and Pezo, Milada L. and Banjac, Vojislav and Jovanović, Aca and Krulj, Jelena and Kojić, Jovana and Kojić, Predrag",
year = "2020",
abstract = "The mixing quality of the pigeon diet mix was studied after the mixing in the Ross-type static mixer (pre-mixer) and the vertical feed mixer (final mixer in the line). Three different experiments were performed: firstly, the possibilities of static mixer were investigated, secondly the blending performance of the vertical feed mixer, and the combination of these approaches in the third experiment. The Discrete Element Method was used in numerical modelling of granular flow in the pre-mixer and the vertical feed mixer, to predict the inter-particle mixing quality, and the results of the mixing. The results of the model were compared with appropriate experiments. The main goal was to foresee the behaviour of mixture in two type of mixers and to evaluate the combined mixing action of these two mixers, in order to explore the possibilities to increase the mixing quality, shorten the mixing time and to reduce the energy consumption.",
journal = "Powder Technology",
title = "Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach",
volume = "375",
pages = "20-27",
doi = "10.1016/j.powtec.2020.07.104"
}

Pezo, L., Pezo, M. L., Banjac, V., Jovanović, A., Krulj, J., Kojić, J.,& Kojić, P.. (2020). Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach. in Powder Technology, 375, 20-27.
https://doi.org/10.1016/j.powtec.2020.07.104

Pezo L, Pezo ML, Banjac V, Jovanović A, Krulj J, Kojić J, Kojić P. Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach. in Powder Technology. 2020;375:20-27.
doi:10.1016/j.powtec.2020.07.104 .

Pezo, Lato, Pezo, Milada L., Banjac, Vojislav, Jovanović, Aca, Krulj, Jelena, Kojić, Jovana, Kojić, Predrag, "Blending performance of the coupled Ross static mixer and vertical feed mixer - Discrete element model approach" in Powder Technology, 375 (2020):20-27,
https://doi.org/10.1016/j.powtec.2020.07.104 . .

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Pezo, Lato
AU  - Jovanović, Aca
AU  - Terzić, Anja
AU  - Andrić, Ljubiša
AU  - Lončar, Biljana
AU  - Kojić, Predrag
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0032591018304480
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7719
AB  - In this paper, five types of horizontal single-pitch screw conveyors with modified geometry, with three different lengths (400, 600 and 800 mm) were investigated for transport and auxiliary mixing action of two materials: natural zeolite and quartz aggregate (sand) with particle sizes 3, 4 and 5 mm. The geometry of the screw transporter is changed by welding three additional helices oriented in the same or the opposite direction from screw cutting edges, enabling the premixing of materials, during the transport. The proper mixing of the observed materials provides an adequate disposition of zeolite particles within the composite and prevents agglomeration and interference with cement hydration. Zeolite application as a binder in a building material is a possible solution to environmental pollution problems caused by cement production. The influences of screw length, particle diameter, the studied geometry variations of screw design, on the mixing performances of the screw conveyor-mixer during material transport were explored. All investigations were performed experimentally and numerically, by using Discrete Element Method (DEM). The experimental results and the results of the DEM investigation were used for the development of mathematical models for the prediction of mixing quality, which are presented in the form of second order polynomial and artificial neural network model.
T2  - Powder Technology
T1  - Discrete element model of particle transport and premixing action in modified screw conveyors
VL  - 336
SP  - 255
EP  - 264
DO  - 10.1016/j.powtec.2018.06.009
ER  - 

@article{
author = "Pezo, Milada L. and Pezo, Lato and Jovanović, Aca and Terzić, Anja and Andrić, Ljubiša and Lončar, Biljana and Kojić, Predrag",
year = "2018",
abstract = "In this paper, five types of horizontal single-pitch screw conveyors with modified geometry, with three different lengths (400, 600 and 800 mm) were investigated for transport and auxiliary mixing action of two materials: natural zeolite and quartz aggregate (sand) with particle sizes 3, 4 and 5 mm. The geometry of the screw transporter is changed by welding three additional helices oriented in the same or the opposite direction from screw cutting edges, enabling the premixing of materials, during the transport. The proper mixing of the observed materials provides an adequate disposition of zeolite particles within the composite and prevents agglomeration and interference with cement hydration. Zeolite application as a binder in a building material is a possible solution to environmental pollution problems caused by cement production. The influences of screw length, particle diameter, the studied geometry variations of screw design, on the mixing performances of the screw conveyor-mixer during material transport were explored. All investigations were performed experimentally and numerically, by using Discrete Element Method (DEM). The experimental results and the results of the DEM investigation were used for the development of mathematical models for the prediction of mixing quality, which are presented in the form of second order polynomial and artificial neural network model.",
journal = "Powder Technology",
title = "Discrete element model of particle transport and premixing action in modified screw conveyors",
volume = "336",
pages = "255-264",
doi = "10.1016/j.powtec.2018.06.009"
}

Pezo, M. L., Pezo, L., Jovanović, A., Terzić, A., Andrić, L., Lončar, B.,& Kojić, P.. (2018). Discrete element model of particle transport and premixing action in modified screw conveyors. in Powder Technology, 336, 255-264.
https://doi.org/10.1016/j.powtec.2018.06.009

Pezo ML, Pezo L, Jovanović A, Terzić A, Andrić L, Lončar B, Kojić P. Discrete element model of particle transport and premixing action in modified screw conveyors. in Powder Technology. 2018;336:255-264.
doi:10.1016/j.powtec.2018.06.009 .

Pezo, Milada L., Pezo, Lato, Jovanović, Aca, Terzić, Anja, Andrić, Ljubiša, Lončar, Biljana, Kojić, Predrag, "Discrete element model of particle transport and premixing action in modified screw conveyors" in Powder Technology, 336 (2018):255-264,
https://doi.org/10.1016/j.powtec.2018.06.009 . .