TY  - JOUR
AU  - Bukur, Dragomir B.
AU  - Mandić, Miloš
AU  - Todić, Branislav
AU  - Nikačević, Nikola
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4452
AB  - In this study we investigate performance characteristics (catalyst effectiveness, CH4 selectivity, and hydrocarbon product distribution) of with a highly active Co/Re/Al(2)O(3 )catalyst particle for Fischer-Tropsch synthesis. In numerical simulations we utilize kinetic parameters for CO consumption rate, CH4 formation rate and hydrocarbon formation rates (C-2+ hydrocarbons) determined from experiments with this catalyst to study effects of catalyst activity, catalyst particle shape (sphere, slab, solid and hollow cylinder), size (i.e. diffusion length), catalyst distribution (uniform vs. eggshell type distribution for a spherical particle) and process conditions (temperature, pressure, syngas composition and conversion level) on the catalyst performance. With increase in Thiele modulus (i.e. particle size at a fixed set of process conditions) we observe increasing H-2/CO ratio profile towards the center of the particle resulting in increase of local and average CH4 selectivity. The goal is to find conditions which allow one to use sufficiently large particles to reduce pressure drop, while avoiding negative influence of diffusional limitations on selectivity and activity. For each catalyst particle shape we determined values of Thiele modulus, i.e. characteristic length of diffusion, corresponding to the upper limit of the kinetic region, and investigated how it changes with operating conditions. We found that simultaneous increase of pressure and the use of syngas with H-2/CO feed ratio of 1.4-1.7 is the best strategy for mitigating the negative impact of intraparticle diffusional limitations on CH4 selectivity. For a spherical particle of 1 mm in diameter, one can achieve CH4 selectivity of 5.6% with catalyst effectiveness factor of 1.07 at the reactor inlet by operating at 50 bar, 473 K and H-2/CO = 1.4.
PB  - Elsevier, Amsterdam
T2  - Catalysis Today
T1  - Pore diffusion effects on catalyst effectiveness and selectivity of cobalt based Fischer-Tropsch catalyst
EP  - 155
SP  - 146
VL  - 343
DO  - 10.1016/j.cattod.2018.10.069
ER  - 

@article{
author = "Bukur, Dragomir B. and Mandić, Miloš and Todić, Branislav and Nikačević, Nikola",
year = "2020",
abstract = "In this study we investigate performance characteristics (catalyst effectiveness, CH4 selectivity, and hydrocarbon product distribution) of with a highly active Co/Re/Al(2)O(3 )catalyst particle for Fischer-Tropsch synthesis. In numerical simulations we utilize kinetic parameters for CO consumption rate, CH4 formation rate and hydrocarbon formation rates (C-2+ hydrocarbons) determined from experiments with this catalyst to study effects of catalyst activity, catalyst particle shape (sphere, slab, solid and hollow cylinder), size (i.e. diffusion length), catalyst distribution (uniform vs. eggshell type distribution for a spherical particle) and process conditions (temperature, pressure, syngas composition and conversion level) on the catalyst performance. With increase in Thiele modulus (i.e. particle size at a fixed set of process conditions) we observe increasing H-2/CO ratio profile towards the center of the particle resulting in increase of local and average CH4 selectivity. The goal is to find conditions which allow one to use sufficiently large particles to reduce pressure drop, while avoiding negative influence of diffusional limitations on selectivity and activity. For each catalyst particle shape we determined values of Thiele modulus, i.e. characteristic length of diffusion, corresponding to the upper limit of the kinetic region, and investigated how it changes with operating conditions. We found that simultaneous increase of pressure and the use of syngas with H-2/CO feed ratio of 1.4-1.7 is the best strategy for mitigating the negative impact of intraparticle diffusional limitations on CH4 selectivity. For a spherical particle of 1 mm in diameter, one can achieve CH4 selectivity of 5.6% with catalyst effectiveness factor of 1.07 at the reactor inlet by operating at 50 bar, 473 K and H-2/CO = 1.4.",
publisher = "Elsevier, Amsterdam",
journal = "Catalysis Today",
title = "Pore diffusion effects on catalyst effectiveness and selectivity of cobalt based Fischer-Tropsch catalyst",
pages = "155-146",
volume = "343",
doi = "10.1016/j.cattod.2018.10.069"
}

Bukur, D. B., Mandić, M., Todić, B.,& Nikačević, N.. (2020). Pore diffusion effects on catalyst effectiveness and selectivity of cobalt based Fischer-Tropsch catalyst. in Catalysis Today
Elsevier, Amsterdam., 343, 146-155.
https://doi.org/10.1016/j.cattod.2018.10.069

Bukur DB, Mandić M, Todić B, Nikačević N. Pore diffusion effects on catalyst effectiveness and selectivity of cobalt based Fischer-Tropsch catalyst. in Catalysis Today. 2020;343:146-155.
doi:10.1016/j.cattod.2018.10.069 .

Bukur, Dragomir B., Mandić, Miloš, Todić, Branislav, Nikačević, Nikola, "Pore diffusion effects on catalyst effectiveness and selectivity of cobalt based Fischer-Tropsch catalyst" in Catalysis Today, 343 (2020):146-155,
https://doi.org/10.1016/j.cattod.2018.10.069 . .

TY  - JOUR
AU  - Nikačević, Nikola
AU  - Todić, Branislav
AU  - Mandić, Miloš
AU  - Petkovska, Menka
AU  - Bukur, Dragomir B.
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4453
AB  - One-dimensional pseudo-homogenous dynamic reactor model, incorporating detailed Fischer-Tropsch kinetics, was applied in a theoretical analysis of forced periodic operations. A milli-scale fixed-bed reactor was analyzed, using design and operation parameters, obtained previously in a steady-state optimization. Dynamic optimization and NLP methods were utilized to obtain optimal values of amplitude(s), frequency and phase shift(s) of sine-wave variation of inputs, around the corresponding optimal steady-state values, which maximize the productivity of C5+ hydrocarbons. Inlet variables that were modulated are: coolant temperature, reactants molar ratio, mass flow rate and pressure. In addition to the single input forcing, simultaneous modulations of multiple inputs were also considered, with combinations of the listed inlet variables. Among the single input cases, periodic variation of the coolant temperature resulted in the highest relative improvement of C5+, productivity by 30%. Multiple inputs forcing showed additional potential for improvement, resulting in relative c(5+) productivity increase of 52% for synchronized modulation of the coolant temperature, reactants molar ratio and mass flow rate. However, the increase in C5+ productivity is accompanied with relative increase in methane selectivity of 22-33% (relative to the steady-state value). The results suggest that, in the case of multiple input variations with high amplitudes, modulation of the inlet reactants molar ratio mainly contributes to the increase of CO conversion (e.g. reaction rate), the coolant temperature forcing slightly increases selectivity towards the desirable higher hydrocarbons (C5+), while the variation of the inlet mass flow rate enables better reaction temperature control and prevents a thermal runway.
PB  - Elsevier, Amsterdam
T2  - Catalysis Today
T1  - Optimization of forced periodic operations in milli-scale fixed bed reactor for Fischer-Tropsch synthesis
EP  - 164
SP  - 156
VL  - 343
DO  - 10.1016/j.cattod.2018.12.032
ER  - 

@article{
author = "Nikačević, Nikola and Todić, Branislav and Mandić, Miloš and Petkovska, Menka and Bukur, Dragomir B.",
year = "2020",
abstract = "One-dimensional pseudo-homogenous dynamic reactor model, incorporating detailed Fischer-Tropsch kinetics, was applied in a theoretical analysis of forced periodic operations. A milli-scale fixed-bed reactor was analyzed, using design and operation parameters, obtained previously in a steady-state optimization. Dynamic optimization and NLP methods were utilized to obtain optimal values of amplitude(s), frequency and phase shift(s) of sine-wave variation of inputs, around the corresponding optimal steady-state values, which maximize the productivity of C5+ hydrocarbons. Inlet variables that were modulated are: coolant temperature, reactants molar ratio, mass flow rate and pressure. In addition to the single input forcing, simultaneous modulations of multiple inputs were also considered, with combinations of the listed inlet variables. Among the single input cases, periodic variation of the coolant temperature resulted in the highest relative improvement of C5+, productivity by 30%. Multiple inputs forcing showed additional potential for improvement, resulting in relative c(5+) productivity increase of 52% for synchronized modulation of the coolant temperature, reactants molar ratio and mass flow rate. However, the increase in C5+ productivity is accompanied with relative increase in methane selectivity of 22-33% (relative to the steady-state value). The results suggest that, in the case of multiple input variations with high amplitudes, modulation of the inlet reactants molar ratio mainly contributes to the increase of CO conversion (e.g. reaction rate), the coolant temperature forcing slightly increases selectivity towards the desirable higher hydrocarbons (C5+), while the variation of the inlet mass flow rate enables better reaction temperature control and prevents a thermal runway.",
publisher = "Elsevier, Amsterdam",
journal = "Catalysis Today",
title = "Optimization of forced periodic operations in milli-scale fixed bed reactor for Fischer-Tropsch synthesis",
pages = "164-156",
volume = "343",
doi = "10.1016/j.cattod.2018.12.032"
}

Nikačević, N., Todić, B., Mandić, M., Petkovska, M.,& Bukur, D. B.. (2020). Optimization of forced periodic operations in milli-scale fixed bed reactor for Fischer-Tropsch synthesis. in Catalysis Today
Elsevier, Amsterdam., 343, 156-164.
https://doi.org/10.1016/j.cattod.2018.12.032

Nikačević N, Todić B, Mandić M, Petkovska M, Bukur DB. Optimization of forced periodic operations in milli-scale fixed bed reactor for Fischer-Tropsch synthesis. in Catalysis Today. 2020;343:156-164.
doi:10.1016/j.cattod.2018.12.032 .

Nikačević, Nikola, Todić, Branislav, Mandić, Miloš, Petkovska, Menka, Bukur, Dragomir B., "Optimization of forced periodic operations in milli-scale fixed bed reactor for Fischer-Tropsch synthesis" in Catalysis Today, 343 (2020):156-164,
https://doi.org/10.1016/j.cattod.2018.12.032 . .

TY  - JOUR
AU  - Bukur, Dragomir B.
AU  - Mandić, Miloš
AU  - Todić, Branislav
AU  - Nikačević, Nikola
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4132
PB  - Amer Chemical Soc, Washington
T2  - Abstracts of Papers of the American Chemical Society
T1  - Influence of intraparticle diffusion on effectiveness factor and methane selectivity of a cobalt based Fischer-Tropsch catalyst
VL  - 258
UR  - https://hdl.handle.net/21.15107/rcub_technorep_4132
ER  - 

@article{
author = "Bukur, Dragomir B. and Mandić, Miloš and Todić, Branislav and Nikačević, Nikola",
year = "2019",
publisher = "Amer Chemical Soc, Washington",
journal = "Abstracts of Papers of the American Chemical Society",
title = "Influence of intraparticle diffusion on effectiveness factor and methane selectivity of a cobalt based Fischer-Tropsch catalyst",
volume = "258",
url = "https://hdl.handle.net/21.15107/rcub_technorep_4132"
}

Bukur, D. B., Mandić, M., Todić, B.,& Nikačević, N.. (2019). Influence of intraparticle diffusion on effectiveness factor and methane selectivity of a cobalt based Fischer-Tropsch catalyst. in Abstracts of Papers of the American Chemical Society
Amer Chemical Soc, Washington., 258.
https://hdl.handle.net/21.15107/rcub_technorep_4132

Bukur DB, Mandić M, Todić B, Nikačević N. Influence of intraparticle diffusion on effectiveness factor and methane selectivity of a cobalt based Fischer-Tropsch catalyst. in Abstracts of Papers of the American Chemical Society. 2019;258.
https://hdl.handle.net/21.15107/rcub_technorep_4132 .

Bukur, Dragomir B., Mandić, Miloš, Todić, Branislav, Nikačević, Nikola, "Influence of intraparticle diffusion on effectiveness factor and methane selectivity of a cobalt based Fischer-Tropsch catalyst" in Abstracts of Papers of the American Chemical Society, 258 (2019),
https://hdl.handle.net/21.15107/rcub_technorep_4132 .

TY  - JOUR
AU  - Mandić, Miloš
AU  - Dikić, Vladimir
AU  - Petkovska, Menka
AU  - Todić, Branislav
AU  - Bukur, Dragomir B.
AU  - Nikačević, Nikola
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3846
AB  - Dynamic performance of a milli-scale fixed bed reactor for Fischer-Tropsch synthesis (FTS) was studied using a dynamic pseudo-homogeneous 1D reactor model. The model uses detailed kinetics to describe the rates of FTS product formation. Dynamic responses of the process variables and main performance indicators, including productivity of C-5(+) hydrocarbons and CH4 selectivity, to input step changes, were analyzed. Total of 7 inlet variables were used in step-change-response analysis, with different magnitudes of change and for two initial steady-state conditions. Reactor simulations show highly nonlinear behavior due to phenomena coupling and fast dynamics due to system small scale and intensified rates within. In addition, reactor model shows instability related to thermal runaway with certain magnitudes of step change of coolant temperature and feed flow rate. The analysis outlines the effects of potential process disturbances on operation of milli-scale fixed bed reactor for FTS and provides general guidelines for control systems.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Chemical Engineering Science
T1  - Dynamic analysis of millimetre-scale fixed bed reactors for Fischer-Tropsch synthesis
EP  - 447
SP  - 434
VL  - 192
DO  - 10.1016/j.ces.2018.07.052
ER  - 

@article{
author = "Mandić, Miloš and Dikić, Vladimir and Petkovska, Menka and Todić, Branislav and Bukur, Dragomir B. and Nikačević, Nikola",
year = "2018",
abstract = "Dynamic performance of a milli-scale fixed bed reactor for Fischer-Tropsch synthesis (FTS) was studied using a dynamic pseudo-homogeneous 1D reactor model. The model uses detailed kinetics to describe the rates of FTS product formation. Dynamic responses of the process variables and main performance indicators, including productivity of C-5(+) hydrocarbons and CH4 selectivity, to input step changes, were analyzed. Total of 7 inlet variables were used in step-change-response analysis, with different magnitudes of change and for two initial steady-state conditions. Reactor simulations show highly nonlinear behavior due to phenomena coupling and fast dynamics due to system small scale and intensified rates within. In addition, reactor model shows instability related to thermal runaway with certain magnitudes of step change of coolant temperature and feed flow rate. The analysis outlines the effects of potential process disturbances on operation of milli-scale fixed bed reactor for FTS and provides general guidelines for control systems.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Chemical Engineering Science",
title = "Dynamic analysis of millimetre-scale fixed bed reactors for Fischer-Tropsch synthesis",
pages = "447-434",
volume = "192",
doi = "10.1016/j.ces.2018.07.052"
}

Mandić, M., Dikić, V., Petkovska, M., Todić, B., Bukur, D. B.,& Nikačević, N.. (2018). Dynamic analysis of millimetre-scale fixed bed reactors for Fischer-Tropsch synthesis. in Chemical Engineering Science
Pergamon-Elsevier Science Ltd, Oxford., 192, 434-447.
https://doi.org/10.1016/j.ces.2018.07.052

Mandić M, Dikić V, Petkovska M, Todić B, Bukur DB, Nikačević N. Dynamic analysis of millimetre-scale fixed bed reactors for Fischer-Tropsch synthesis. in Chemical Engineering Science. 2018;192:434-447.
doi:10.1016/j.ces.2018.07.052 .

Mandić, Miloš, Dikić, Vladimir, Petkovska, Menka, Todić, Branislav, Bukur, Dragomir B., Nikačević, Nikola, "Dynamic analysis of millimetre-scale fixed bed reactors for Fischer-Tropsch synthesis" in Chemical Engineering Science, 192 (2018):434-447,
https://doi.org/10.1016/j.ces.2018.07.052 . .

TY  - JOUR
AU  - Stamenić, Marko
AU  - Dikić, Vladimir
AU  - Mandić, Miloš
AU  - Todić, Branislav
AU  - Bukur, Dragomir B.
AU  - Nikačević, Nikola
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3964
AB  - Our previously developed mathematical model is used for parametric sensitivity and optimization study of conventional and milliscale fixed-bed reactors (FBRs) for Fischer-Tropsch synthesis (FTS). Five indicators are chosen to analyze the influence of eight parameters on the FBRs performance. The results show the scale of the effects caused by changing single parameter values and highlight the most important ones. Subsequently, the model is used to perform a rigorous multivariable optimization of the FBRs performance in the steady state. Three optimization functions are used, depicting different reactor costs. Four design parameters (tube length and diameter, particle diameter, and catalyst layer thickness) and five operating parameters (inlet and wall temperature, inlet pressure, H-2/CO ratio, velocity) are optimized simultaneously. The results indicate that optimal results, in terms of reactor design and operating parameters and FBR performance, highly depend on the selected objective function and values of constrained parameters (especially methane selectivity and the partial pressure of water).
PB  - Amer Chemical Soc, Washington
T2  - Industrial & Engineering Chemistry Research
T1  - Multiscale and Multiphase Model of Fixed-Bed Reactors for Fischer-Tropsch Synthesis: Optimization Study
EP  - 3162
IS  - 9
SP  - 3149
VL  - 57
DO  - 10.1021/acs.iecr.7b04914
ER  - 

@article{
author = "Stamenić, Marko and Dikić, Vladimir and Mandić, Miloš and Todić, Branislav and Bukur, Dragomir B. and Nikačević, Nikola",
year = "2018",
abstract = "Our previously developed mathematical model is used for parametric sensitivity and optimization study of conventional and milliscale fixed-bed reactors (FBRs) for Fischer-Tropsch synthesis (FTS). Five indicators are chosen to analyze the influence of eight parameters on the FBRs performance. The results show the scale of the effects caused by changing single parameter values and highlight the most important ones. Subsequently, the model is used to perform a rigorous multivariable optimization of the FBRs performance in the steady state. Three optimization functions are used, depicting different reactor costs. Four design parameters (tube length and diameter, particle diameter, and catalyst layer thickness) and five operating parameters (inlet and wall temperature, inlet pressure, H-2/CO ratio, velocity) are optimized simultaneously. The results indicate that optimal results, in terms of reactor design and operating parameters and FBR performance, highly depend on the selected objective function and values of constrained parameters (especially methane selectivity and the partial pressure of water).",
publisher = "Amer Chemical Soc, Washington",
journal = "Industrial & Engineering Chemistry Research",
title = "Multiscale and Multiphase Model of Fixed-Bed Reactors for Fischer-Tropsch Synthesis: Optimization Study",
pages = "3162-3149",
number = "9",
volume = "57",
doi = "10.1021/acs.iecr.7b04914"
}

Stamenić, M., Dikić, V., Mandić, M., Todić, B., Bukur, D. B.,& Nikačević, N.. (2018). Multiscale and Multiphase Model of Fixed-Bed Reactors for Fischer-Tropsch Synthesis: Optimization Study. in Industrial & Engineering Chemistry Research
Amer Chemical Soc, Washington., 57(9), 3149-3162.
https://doi.org/10.1021/acs.iecr.7b04914

Stamenić M, Dikić V, Mandić M, Todić B, Bukur DB, Nikačević N. Multiscale and Multiphase Model of Fixed-Bed Reactors for Fischer-Tropsch Synthesis: Optimization Study. in Industrial & Engineering Chemistry Research. 2018;57(9):3149-3162.
doi:10.1021/acs.iecr.7b04914 .

Stamenić, Marko, Dikić, Vladimir, Mandić, Miloš, Todić, Branislav, Bukur, Dragomir B., Nikačević, Nikola, "Multiscale and Multiphase Model of Fixed-Bed Reactors for Fischer-Tropsch Synthesis: Optimization Study" in Industrial & Engineering Chemistry Research, 57, no. 9 (2018):3149-3162,
https://doi.org/10.1021/acs.iecr.7b04914 . .

TY  - JOUR
AU  - Todić, Branislav
AU  - Mandić, Miloš
AU  - Nikačević, Nikola
AU  - Bukur, Dragomir B.
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3996
AB  - A two-dimensional pseudo-homogeneous model of wall-cooled fixed bed Fischer-Tropsch synthesis (FTS) reactor with Co/Re/gamma-Al2O3 catalyst was developed to study the effect of process and design parameters on heat generation and removal characteristics. The influence of liquid-phase formation on heat transport was accounted for by using two-phase correlations. The effect of intraparticle diffusion on heat generation was considered. Detailed numerical simulations were performed to analyze the effect of process and design parameters on the reactor performance in terms of heat management. Results show that thermal behavior of FTS fixed bed reactors is very sensitive and any large disturbances can lead to temperature runaway. Large tube diameters are shown to be particularly unfavorable, with d (t)  gt  5 cm resulting in axial and radial gradients greater than 20 K and 13 K, respectively. The importance of detailed reactor modeling when designing and optimizing FTS fixed bed reactors is highlighted.
PB  - Korean Institute Chemical  Engineers, Seoul
T2  - Korean Journal of Chemical Engineering
T1  - Effects of process and design parameters on heat management in fixed bed Fischer-Tropsch synthesis reactor
EP  - 889
IS  - 4
SP  - 875
VL  - 35
DO  - 10.1007/s11814-017-0335-3
ER  - 

@article{
author = "Todić, Branislav and Mandić, Miloš and Nikačević, Nikola and Bukur, Dragomir B.",
year = "2018",
abstract = "A two-dimensional pseudo-homogeneous model of wall-cooled fixed bed Fischer-Tropsch synthesis (FTS) reactor with Co/Re/gamma-Al2O3 catalyst was developed to study the effect of process and design parameters on heat generation and removal characteristics. The influence of liquid-phase formation on heat transport was accounted for by using two-phase correlations. The effect of intraparticle diffusion on heat generation was considered. Detailed numerical simulations were performed to analyze the effect of process and design parameters on the reactor performance in terms of heat management. Results show that thermal behavior of FTS fixed bed reactors is very sensitive and any large disturbances can lead to temperature runaway. Large tube diameters are shown to be particularly unfavorable, with d (t)  gt  5 cm resulting in axial and radial gradients greater than 20 K and 13 K, respectively. The importance of detailed reactor modeling when designing and optimizing FTS fixed bed reactors is highlighted.",
publisher = "Korean Institute Chemical  Engineers, Seoul",
journal = "Korean Journal of Chemical Engineering",
title = "Effects of process and design parameters on heat management in fixed bed Fischer-Tropsch synthesis reactor",
pages = "889-875",
number = "4",
volume = "35",
doi = "10.1007/s11814-017-0335-3"
}

Todić, B., Mandić, M., Nikačević, N.,& Bukur, D. B.. (2018). Effects of process and design parameters on heat management in fixed bed Fischer-Tropsch synthesis reactor. in Korean Journal of Chemical Engineering
Korean Institute Chemical  Engineers, Seoul., 35(4), 875-889.
https://doi.org/10.1007/s11814-017-0335-3

Todić B, Mandić M, Nikačević N, Bukur DB. Effects of process and design parameters on heat management in fixed bed Fischer-Tropsch synthesis reactor. in Korean Journal of Chemical Engineering. 2018;35(4):875-889.
doi:10.1007/s11814-017-0335-3 .

Todić, Branislav, Mandić, Miloš, Nikačević, Nikola, Bukur, Dragomir B., "Effects of process and design parameters on heat management in fixed bed Fischer-Tropsch synthesis reactor" in Korean Journal of Chemical Engineering, 35, no. 4 (2018):875-889,
https://doi.org/10.1007/s11814-017-0335-3 . .

TY  - JOUR
AU  - Stamenić, Marko
AU  - Dikić, Vladimir
AU  - Mandić, Miloš
AU  - Todić, Branislav
AU  - Bukur, Dragomir B.
AU  - Nikačević, Nikola
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3542
AB  - A multiphase fixed-bed reactor (FBR) model for Fischer Tropsch Synthesis has been developed. A high level of details is considered for description of the phenomena on the reactor and particle scale. Detailed kinetics is used, with parameters estimated from experiments with a cobalt-based catalyst. Model robustness has been validated using literature data. Performance analysis was made for a conventional scale FBR with egg-shell distribution of catalyst and a millimeter-scale FBR with small particles and uniform distribution. In both cases, diffusion limitations are almost eliminated due to use of small diffusion lengths. For similar qualitative results, a milli-scaled design would result in a significantly lower reactor volume, but the capital costs could be high due to large wall area and a vast number of tubes. Heat removal is efficient in both cases, and pressure drop in the milli-scale reactor is low due to the use of a shorter bed and lower velocity.
PB  - Amer Chemical Soc, Washington
T2  - Industrial & Engineering Chemistry Research
T1  - Multiscale and Multiphase Model of Fixed Bed Reactors for Fischer-Tropsch Synthesis: Intensification Possibilities Study
EP  - 9979
IS  - 36
SP  - 9964
VL  - 56
DO  - 10.1021/acs.iecr.7b02467
ER  - 

@article{
author = "Stamenić, Marko and Dikić, Vladimir and Mandić, Miloš and Todić, Branislav and Bukur, Dragomir B. and Nikačević, Nikola",
year = "2017",
abstract = "A multiphase fixed-bed reactor (FBR) model for Fischer Tropsch Synthesis has been developed. A high level of details is considered for description of the phenomena on the reactor and particle scale. Detailed kinetics is used, with parameters estimated from experiments with a cobalt-based catalyst. Model robustness has been validated using literature data. Performance analysis was made for a conventional scale FBR with egg-shell distribution of catalyst and a millimeter-scale FBR with small particles and uniform distribution. In both cases, diffusion limitations are almost eliminated due to use of small diffusion lengths. For similar qualitative results, a milli-scaled design would result in a significantly lower reactor volume, but the capital costs could be high due to large wall area and a vast number of tubes. Heat removal is efficient in both cases, and pressure drop in the milli-scale reactor is low due to the use of a shorter bed and lower velocity.",
publisher = "Amer Chemical Soc, Washington",
journal = "Industrial & Engineering Chemistry Research",
title = "Multiscale and Multiphase Model of Fixed Bed Reactors for Fischer-Tropsch Synthesis: Intensification Possibilities Study",
pages = "9979-9964",
number = "36",
volume = "56",
doi = "10.1021/acs.iecr.7b02467"
}

Stamenić, M., Dikić, V., Mandić, M., Todić, B., Bukur, D. B.,& Nikačević, N.. (2017). Multiscale and Multiphase Model of Fixed Bed Reactors for Fischer-Tropsch Synthesis: Intensification Possibilities Study. in Industrial & Engineering Chemistry Research
Amer Chemical Soc, Washington., 56(36), 9964-9979.
https://doi.org/10.1021/acs.iecr.7b02467

Stamenić M, Dikić V, Mandić M, Todić B, Bukur DB, Nikačević N. Multiscale and Multiphase Model of Fixed Bed Reactors for Fischer-Tropsch Synthesis: Intensification Possibilities Study. in Industrial & Engineering Chemistry Research. 2017;56(36):9964-9979.
doi:10.1021/acs.iecr.7b02467 .

Stamenić, Marko, Dikić, Vladimir, Mandić, Miloš, Todić, Branislav, Bukur, Dragomir B., Nikačević, Nikola, "Multiscale and Multiphase Model of Fixed Bed Reactors for Fischer-Tropsch Synthesis: Intensification Possibilities Study" in Industrial & Engineering Chemistry Research, 56, no. 36 (2017):9964-9979,
https://doi.org/10.1021/acs.iecr.7b02467 . .

TY  - JOUR
AU  - Mandić, Miloš
AU  - Todić, Branislav
AU  - Zivanić, Ljiljana
AU  - Nikačević, Nikola
AU  - Bukur, Dragomir B.
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3688
AB  - We investigate effects of catalyst activity, catalyst particle shape (sphere, slab, and hollow cylinder), size (i.e., diffusion length), catalyst distribution (uniform vs eggshell type distribution for a spherical particle), and process conditions (temperature, pressure, syngas composition, and conversion level) on catalyst effectiveness factor and methane selectivity inside the catalyst pellet. In numerical simulations we utilize kinetic parameters for CO consumption rate and CH4 formation rate determined from experiments with a highly active Co/Re/gamma-Al2O3 catalyst. It is found that the use of small spherical particles (0.2-0.5 mm) or eggshell distribution for larger spherical particles with catalyst layer thickness less than approximately 0.13 mm is needed to avoid negative impact of diffusional limitations on CH4 selectivity under typical Fischer Tropsch synthesis operating conditions. For monolith reactors with wash-coated catalyst, diffusional limitations can be avoided by using a catalyst layer thickness less than 0.11 nun at base case conditions (473 K, 25 bar, and H-2/CO molar ratio of 2).
PB  - Amer Chemical Soc, Washington
T2  - Industrial & Engineering Chemistry Research
T1  - Effects of Catalyst Activity, Particle Size and Shape, and Process Conditions on Catalyst Effectiveness and Methane Selectivity for Fischer-Tropsch Reaction: A Modeling Study
EP  - 2745
IS  - 10
SP  - 2733
VL  - 56
DO  - 10.1021/acs.iecr.7b00053
ER  - 

@article{
author = "Mandić, Miloš and Todić, Branislav and Zivanić, Ljiljana and Nikačević, Nikola and Bukur, Dragomir B.",
year = "2017",
abstract = "We investigate effects of catalyst activity, catalyst particle shape (sphere, slab, and hollow cylinder), size (i.e., diffusion length), catalyst distribution (uniform vs eggshell type distribution for a spherical particle), and process conditions (temperature, pressure, syngas composition, and conversion level) on catalyst effectiveness factor and methane selectivity inside the catalyst pellet. In numerical simulations we utilize kinetic parameters for CO consumption rate and CH4 formation rate determined from experiments with a highly active Co/Re/gamma-Al2O3 catalyst. It is found that the use of small spherical particles (0.2-0.5 mm) or eggshell distribution for larger spherical particles with catalyst layer thickness less than approximately 0.13 mm is needed to avoid negative impact of diffusional limitations on CH4 selectivity under typical Fischer Tropsch synthesis operating conditions. For monolith reactors with wash-coated catalyst, diffusional limitations can be avoided by using a catalyst layer thickness less than 0.11 nun at base case conditions (473 K, 25 bar, and H-2/CO molar ratio of 2).",
publisher = "Amer Chemical Soc, Washington",
journal = "Industrial & Engineering Chemistry Research",
title = "Effects of Catalyst Activity, Particle Size and Shape, and Process Conditions on Catalyst Effectiveness and Methane Selectivity for Fischer-Tropsch Reaction: A Modeling Study",
pages = "2745-2733",
number = "10",
volume = "56",
doi = "10.1021/acs.iecr.7b00053"
}

Mandić, M., Todić, B., Zivanić, L., Nikačević, N.,& Bukur, D. B.. (2017). Effects of Catalyst Activity, Particle Size and Shape, and Process Conditions on Catalyst Effectiveness and Methane Selectivity for Fischer-Tropsch Reaction: A Modeling Study. in Industrial & Engineering Chemistry Research
Amer Chemical Soc, Washington., 56(10), 2733-2745.
https://doi.org/10.1021/acs.iecr.7b00053

Mandić M, Todić B, Zivanić L, Nikačević N, Bukur DB. Effects of Catalyst Activity, Particle Size and Shape, and Process Conditions on Catalyst Effectiveness and Methane Selectivity for Fischer-Tropsch Reaction: A Modeling Study. in Industrial & Engineering Chemistry Research. 2017;56(10):2733-2745.
doi:10.1021/acs.iecr.7b00053 .

Mandić, Miloš, Todić, Branislav, Zivanić, Ljiljana, Nikačević, Nikola, Bukur, Dragomir B., "Effects of Catalyst Activity, Particle Size and Shape, and Process Conditions on Catalyst Effectiveness and Methane Selectivity for Fischer-Tropsch Reaction: A Modeling Study" in Industrial & Engineering Chemistry Research, 56, no. 10 (2017):2733-2745,
https://doi.org/10.1021/acs.iecr.7b00053 . .