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1
Content available remote Symulacja i optymalizacja syntezy octanu metylu metodą katalitycznej destylacji reaktywnej w oprogramowaniu Aspen Plus
Xiaoxuan Wang, Ling Yu
Przemysł Chemiczny
|
2024
|
T. 103, nr 1
59--65
PL
Synteza octanu metylu metodą katalitycznej destylacji reaktywnej została zasymulowana przy użyciu oprogramowania Aspen Plus. Optymalne parametry to: liczba półek 43, podawanie kwasu octowego na 12. półkę, podawanie metanolu na 41. półkę, refluks 1,4, stosunek alkidów 1,1. Zastosowanie, w tych samych warunkach, jednowieżowego systemu destylacji reaktywnej umożliwiło znaczne zmniejszenie zużycia energii i inwestycji w sprzęt w porównaniu z systemem dwuwieżowym. Roczne średnie koszty produkcji były o 38,88% mniejsze niż w przypadku procesu dwuwieżowego
EN
Catalytic reactive distn. of AcOMe was simulated by using Aspen Plus software. The optimum theor. plate number was 43, the optimum AcOH feeding position was the 12thplate, the optimum MeOH feeding position was the 41st plate, the optimum reflux ratio was 1.4, and the optimum alkyd ratio was 1.1. Under basically the same conditions, use of the single-tower reactive distn. system can greatly reduce energy consumption and equipment investment when compared with the 2-tower system. The annual av. costs prodn. were by 38.88% lower than that of the 2-tower process.
2
Content available Design and simulation of high purity biodiesel reactive distillation process
Ali Syed Sadiq, Asif Mohammad, Basu Avijit
Polish Journal of Chemical Technology
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2019
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Vol. 21, nr 3
1--7
EN
Biodiesel is a promising energy substitute of fossil fuels since it is produced from renewable and biodegradable sources. In the present work, reactive distillation (RD) process is designed and simulated using Aspen Plus process simulator to produce biodiesel of high purity through esterification reaction. The simultaneous reaction and separation in same unit enhances the biodiesel yield and composition in RD process. Two flowsheets are proposed in present work. In the first flowsheet, the unreacted methanol is recycled back to reactive distillation column. Biodiesel with 99.5 mol% purity is obtained in product stream while the byproduct stream comprises 95.2 mol% water, which has to be treated further. In the second flowsheet, a part of methanol recycle is split and purged. In this case, the biodiesel composition in product stream is 99.7 mol% whereas water composition is 99.9 mol% in byproduct stream, which can be reused for other process without treatment.
3
Content available Dynamic modeling of the isoamyl acetate reactive distillation process
Ali S. S., Hossain SK. S., Asif M.
Polish Journal of Chemical Technology
|
2017
|
Vol. 19, nr 1
59--66
EN
The cost-effectiveness of reactive distillation (RD) processes makes them highly attractive for industrial applications. However, their preliminary design and subsequent scale-up and operation are challenging. Specifically, the response of RD system during fluctuations in process parameters is of paramount importance to ensure the stability of the whole process. As a result of carrying out simulations using Aspen Plus, it is shown that the RD process for isoamyl acetate production was much more economical than conventional reactor distillation configuration under optimized process conditions due to lower utilities consumption, higher conversion and smaller sizes of condenser and reboiler. Rigorous dynamic modeling of RD system was performed to evaluate its sensitivity to disturbances in critical process parameters; the product flow was quite sensitive to disturbances. Even more sensitive was product composition when the disturbance in heat duties of condenser or reboiler led to a temperature decrease. However, positive disturbance in alcohol feed is of particular concern, which clearly made the system unstable.
4
Content available Modified neural network based cascaded control for product composition of reactive distillation
Sakhre V., Jain S., Sapkal V. S., Agarwal D. P.
Polish Journal of Chemical Technology
|
2016
|
Vol. 18, nr 2
111--121
EN
In this research work, neural network based single loop and cascaded control strategies, based on Feed Forward Neural Network trained with Back Propagation (FBPNN) algorithm is carried out to control the product composition of reactive distillation. The FBPNN is modified using the steepest descent method. This modification is suggested for optimization of error function. The weights connecting the input and hidden layer, hidden and output layer is optimized using steepest descent method which causes minimization of mean square error and hence improves the response of the system. FBPNN, as the inferential soft sensor is used for composition estimation of reactive distillation using temperature as a secondary process variable. The optimized temperature profile of the reactive distillation is selected as input to the neural network. Reboiler heat duty is selected as a manipulating variable in case of single loop control strategy while the bottom stage temperature T9 is selected as a manipulating variable for cascaded control strategy. It has been observed that modified FBPNN gives minimum mean square error. It has also been observed from the results that cascaded control structure gives improved dynamic response as compared to the single loop control strategy.
5
Content available A multiscale methodology for CFD simulation of catalytic distillation bale packings
Ding H., Xiang W., Liu Ch.
Polish Journal of Chemical Technology
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2016
|
Vol. 18, nr 1
24--32
EN
A multiscale model for simulating the hydrodynamic behavior of catalytic bale packings has been proposed. This model combines computational fluid dynamics (CFD) and macroscopic calculation. At small scale calculation, the CFD model includes 3-D volume-of-fluid (VOF) simulation within representative elementary unit (REU) under unsteady-state conditions. The REU constitutes gauze and catalyst domain, and porous media model is applied. At large scale calculation, a new mechanistic model deduced from the unit network model is employed. Based on liquid split proportion from small scale calculation, liquid distribution of the entire bale packing can be predicted. To evaluate different packing design, three common bale arrangements, i.e. one-bale, nine-bales and seven-bales, are compared. The area-weighted Christiansen uniformity coefficient is introduced to assess the distribution performance. A comparison between simulation and experimental results is made to validate the multiscale model. The present methodology is proved to be effective to analysis and design of catalytic distillation columns.
6
Content available Simulation and sensitivity analysis for biodiesel production in a reactive distillation column
Agarwal M., Singh K., Chaurasia S. P.
Polish Journal of Chemical Technology
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2012
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Vol. 14, nr 3
59-65
EN
The conventional process for biodiesel production by transesterification is still expensive due to a need of high excess of alcohol required and its recovery by distillation. The use of a reactive distillation process can reduce the amount of alcohol in the feed stream as it works on a simultaneous reaction and separation. In the present study, a mathematical model has been developed for biodiesel production from triglycerides in a reactive distillation column, which has been validated with the reported data and CHEMCAD results. The effects of process parameters such as methanol to oil feed ratio, feed temperature, and reaction time have been investigated. The sensitivity analysis shows that yield of ester increases with methanol to oil ratio and number of stages, however, it decreases with fl ow rate. The MATLAB simulated results show that methanol to oil molar ratio of 5:1 produces 90% (by wt.) of methyl ester in a residence time of 4.7 minutes.
7
Content available Oczyszczanie ścieków technologicznych z kwasu octowego metodą destylacji reaktywnej - modelowanie kinetyki reakcji estryfikacji
Hehlmann J., Sobecki M., Gądek M.
Rocznik Ochrona Środowiska
|
2011
|
Tom 13
859-874
PL
Zainteresowanie ochroną środowiska leży u podstaw zrównoważonej gospodarki światowej. Koncepcja wytrzymałości światowego systemu ekologicznego opiera się na dwóch podstawowych pojęciach: potrzeby i ograniczenia. W myśl tej tezy prowadzone są poszukiwania nowych "ekologicznych" technologii oraz metod modernizacji już istniejących. Destylacja reaktywna jest jednym z tych innowacyjnych trendów. Pomimo faktu, że w przemyśle chemicznym idea tworzenia procesów hybrydowych nie stanowi novum, to jednak dopiero na przestrzeni ostatnich lat, wskutek wzrostu popytu na dodatki do benzyn bezołowiowych, proces destylacji reaktywnej zaczął cieszyć się zainteresowaniem. W roku 1984 koncern Eastman Kodak Chemicals wykorzystując destylację reaktywną rozpoczął produkcję MTBE na skalę przemysłową. Kombinację dziewięciu kolumn destylacyjnych i reaktora zastąpiono jedną kolumną reaktywną [1, 2].
EN
The paper presents possibilities of reactive distillation column application in recovery of acetic acid from waste water and industrial streams. Reaction zone of RD column is equipped with hybrid structural plate. This is new apparatus solution for reactive separation process. There was investigated kinetics of esterification in diluted water solution. Experimental conversion was compared with modeling in process simulator using pseudo homogenous and heterogenous kinetics equation. Hybrid structural plate (Fig. 1b) is a solution that allows to perform the esterification reaction of acetic acid using methanol. The study aimed at mapping the process conditions used in the plate column used in RD column. Satisfying (ca. 50%) conversion rate of 99.5% acetic acid was obtained. The reaction in aqueous solution runs slower, due to the diluted streams of reagents, shift of the equilibrium of reaction and limited use of catalyst accumulated in the perforated container. Presented construction solution, with some modifications, is the subject of the patent application being developed [15]. Esterification of concentrated solutions of acetic acid in plate devices can be described with a heterogeneous model, and diluted with pseudohomogenic model. Mass transport, assuming ideal mixing in the heterogeneous system is very complicated and seems to have a slightly different mechanism for three-phase system (vapour/liquid/solid) in the reactive column with plates working on the idea barbotage than catalytic structural fills. Application of kinetic equations from pseudohomogenic or heterogeneous models is correct for the RD column equipped with only the dumped or structural fill of KATAPAK type [14], working under the streamlined regime.
8
Content available Destylacja reaktywna : stosowane modele procesowe i rozwiązania aparaturowe
Hehlmann J., Gądek M.
Inżynieria i Aparatura Chemiczna
|
2009
|
Nr 3
138-145
PL
W artykule podjęto próbę zwięzłego przybliżenia tematyki destylacji reaktywnej. Umieszczono w nim krótką charakterystykę podstaw termodynamicznych, rozwiązań konstrukcyjnych oraz modeli matematycznych opisujących proces. Artykuł przedstawia również rosnące zainteresowanie destylacją reaktywną ze wskazaniem na nowe obszary aplikacji.
EN
An attempt of concise presentation of reactive distillation is undertaken in the paper. Short characteristic of thermodynamic bases, constructional designs and mathematical models describing the process are discussed. The paper presents also an increasing interest of reactive distillation nowadays indicating new areas of application.
9
Content available Consider reactive separations
Kołodziej A., Jaroszyński M., Janus B., Kleszcz T.
Ars Separatoria Acta
|
2009/2010
|
No. 7
11-20
EN
Reactive separation (RS) is the combination of a chemical (catalytic) reaction and a separation technique. For reactive distillation (RD), the reaction is combined with distillation. Rapid development of RS is the result of growing environmental demands and increasing energy costs. Several processes are performed using RD, such as esterification, etherification (fuel antiknocks), and hydrodesulphurisation. Other RS techniques also develop rapidly. However, the success has not come without some serious problems. The heterogeneous proton catalysts still do not meet the requirements of many processes. The column internals with a built-in catalyst are rather sparse and expensive and their characteristics are not studied well enough. Therefore intensive studies are still being performed. This study presents a brief summary of the processes realisable with the usage of reactive distillation, catalysts, and column internals. Some interesting research results and application examples are also quoted.
10
Content available remote Zastosowanie destylacji reaktywnej szansą na poprawę efektywności procesów chemicznych
Kijeński J., Kędziora A.
Przemysł Chemiczny
|
2006
|
T. 85, nr 10
1431-1439
PL
W ostatnich latach, wskutek wzrostu popytu na dodatki do benzyn bezołowiowych, proces destylacji reaktywnej (RD) zaczął cieszyć się wyjątkowo dużym zainteresowaniem. Zaprezentowano główne zalety płynące z zastosowania RD w procesach przemysłowych. Przedstawiono kilka najciekawszych aktualnych aplikacji oraz dokonano identyfikacji obszarów, dla których zastosowanie RD, może być szczególnie interesującym rozwiązaniem. Przybliżono również termodynamikę, sposób projektowania oraz modele wykorzystywane w procesie destylacji reaktywnej.
EN
A review with 27 refs. covering RD thermodynamics, RD design, selection of hardware for homo and heterogeneous RD, the side reactor concept, column scale-up, RD modelling, and processes for making Me acetate, fuel ethers, and for hydrolysis of esters.
11
Zastosowanie destylacji reaktywnej do syntezy akrylanu metylu
Witczak M., Gumuła T., Grzesik M., Skrzypek J.
Inżynieria i Aparatura Chemiczna
|
2004
|
Nr 3s
174-175
EN
The results of the modeling of methyl acrylate synthesis in the reactive distillation column have been presented. Examined in detail was the influence of important operating and design factors (reactant ratio HBO/HAO, number of stages n, number of the input streams k, reflux ratio R and distillate ratio D) on the final degree of conversion a and product distribution between distillate and bottoms cp.
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