scholarly journals Solution Polymerization of Acrylic Acid Initiated by Redox Couple Na-PS/Na-MBS: Kinetic Model and Transition to Continuous Process

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 850
Author(s):  
Federico Florit ◽  
Paola Rodrigues Bassam ◽  
Alberto Cesana ◽  
Giuseppe Storti
Keyword(s):  
Kinetic Model ◽  
Acrylic Acid ◽  
Continuous Process ◽  
Scale Up ◽  
Tubular Reactor ◽  
Kinetic Scheme ◽  
Redox Couple ◽  
Polymerization Process ◽  
Proposed Model ◽  
Population Balances

This work aims at modeling in detail the polymerization of non-ionized acrylic acid in aqueous solution. The population balances required to evaluate the main average properties of molecular weight were solved by the method of moments. The polymerization process considered is initiated by a persulfate/metabisulfate redox couple and, in particular, the kinetic scheme considers the possible formation of mid-chain radicals and transfer reactions. The proposed model is validated using experimental data collected in a laboratory-scale discontinuous reactor. The developed kinetic model is then used to intensify the discontinuous process by shifting it to a continuous one based on a tubular reactor with intermediate feeds. One of the experimental runs is selected to show how the proposed model can be used to assess the transition from batch to continuous process and allow faster scale-up to industrial scale using a literature approach.

A machine-learning reduced kinetic model for H2S thermal conversion process

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anna Dell’Angelo ◽  
Ecem Muge Andoglu ◽  
Suleyman Kaytakoglu ◽  
Flavio Manenti
Keyword(s):  
Kinetic Model ◽  
Kinetic Scheme ◽  
Thermal Conversion ◽  
Operating Conditions ◽  
Thermal Processes ◽  
Proposed Model ◽  
Wide Range ◽  
Commercial Process ◽  
Detailed Kinetic Model

Abstract H2S is becoming more and more appealing as a source for hydrogen and syngas generation. Its hydrogen production potential is studied by several research groups by means of catalytic and thermal conversions. While the characterization of catalytic processes is strictly dependent on the catalyst adopted and difficult to be generalized, the characterization of thermal processes can be brought back to wide-range validity kinetic models thanks to their homogeneous reaction environments. The present paper is aimed at providing a reduced kinetic scheme for reliable thermal conversion of H2S molecule in pyrolysis and partial oxidation thermal processes. The proposed model consists of 10 reactions and 12 molecular species. Its validation is performed by numerical comparisons with a detailed kinetic model already validated by literature/industrial data at the operating conditions of interest. The validated reduced model could be easily adopted in commercial process simulators for the flow sheeting of H2S conversion processes.

Continuous Production of Biodiesel with Supercritical Methanol: a Simple Compressible Flow Model for Tubular Reactors

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Ruengwit Sawangkeaw ◽  
Witsanee Satayanon ◽  
Kunchana Bunyakiat ◽  
Séverine Camy ◽  
Jean-Stéphane Condoret ◽  
...  
Keyword(s):  
Compressible Flow ◽  
Thermodynamic Model ◽  
Flow Model ◽  
Continuous Production ◽  
Continuous Process ◽  
Tubular Reactor ◽  
Compressibility Factor ◽  
Batch Process ◽  
Supercritical Methanol ◽  
Proposed Model

From an industrial point of view, the continuous process for biodiesel production with supercritical methanol (SCM) is more appropriate than the batch process. However, lab-scale studies on the continuous process have shown that the maximum conversion always remains slightly lower than that obtained in the batch process. This work proposes a simple compressible flow model to predict the conversion of methanol and oils into methyl esters (ME) along the length of a tubular reactor and further demonstrates the effect of the development of the compressibility factor of the reaction mixture upon the conversion efficiency to ME. The governing equation was derived from a general molar balance in the tubular reactor using transesterification kinetics of refined-bleached-deodorized (RBD) palm oil in SCM coupled with a suitable thermodynamic model with adjusted binary interaction parameters. Vapor-liquid equilibrium data for triolein + methanol, methyl oleate + methanol and glycerol + methanol mixtures were obtained from the literature and then refitted with the thermodynamic model consisting of the Peng-Robinson equation of state and MHV2 mixing rules to find the set of adequate interaction parameters. In order to check the validity of the proposed model, the predicted ME contents were compared with observed values in a lab-scale continuous reactor at various operating temperatures, pressures and methanol to oil molar ratios. The proposed model proved to be adequate for predicting the final conversion to ME for operating temperatures below 320°C, when the thermal degradation reactions of unsaturated fatty acids did not interfere. Our results also illustrate the importance of taking into account the development of the compressibility factor with time and reactor length, since this was shown to be the cause of the lower transesterification reaction rate in the tubular SCM process. The findings in this work could be employed as a knowledgebase to further develop a better model for continuous production of biodiesel with SCM in a tubular reactor.

scholarly journals Effect of Aspect Ratio on the Mixing Performance in the Kenics Static Mixer

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 464
Author(s):  
Xingren Jiang ◽  
Ning Yang ◽  
Rijie Wang
Keyword(s):  
Pharmaceutical Industry ◽  
Aspect Ratio ◽  
Flow Reactor ◽  
Mixing Time ◽  
Continuous Process ◽  
Scale Up ◽  
Influence Factors ◽  
Continuous Manufacturing ◽  
Static Mixer ◽  
Mixing Performance

Continuous manufacturing has received increasing interest because of the advantages of intrinsic safety and enhanced mass transfer in the pharmaceutical industry. However, the difficulty for scale-up has limited the application of continuous manufacturing for a long time. Recently, the tubular flow reactor equipped with the Kenics static mixer appears to be a solution for the continuous process scale-up. Although many influence factors on the mixing performance in the Kenics static mixer have been investigated, little research has been carried out on the aspect ratio. In this study, we used the coefficient of variation as the mixing evaluation index to investigate the effect of the aspect ratio (0.2–2) on the Kenics static mixer’s mixing performance. The results indicate that a low aspect ratio helps obtain a shorter mixing time and mixer length. This study suggests that adjusting the aspect ratio of the Kenics static mixer can be a new strategy for the scale-up of a continuous process in the pharmaceutical industry.

scholarly journals Potential applications of halophilic microorganisms for biological treatment of industrial process brines contaminated with aromatics

2021 ◽  
Author(s):  
Thomas Mainka ◽  
David Weirathmüller ◽  
Christoph Herwig ◽  
Stefan Pflügl
Keyword(s):  
Wastewater Treatment ◽  
Process Monitoring ◽  
Industrial Wastewater ◽  
Continuous Process ◽  
Scale Up ◽  
Monitoring And Control ◽  
Saline Wastewater ◽  
Halophilic Microorganisms ◽  
Industrial Sectors ◽  
And Control

Abstract Saline wastewater contaminated with aromatic compounds can be frequently found in various industrial sectors. Those compounds need to be degraded before reuse of wastewater in other process steps or release to the environment. Halophiles have been reported to efficiently degrade aromatics, but their application to treat industrial wastewater is rare. Halophilic processes for industrial wastewater treatment need to satisfy certain requirements: a continuous process mode, low operational expenditures, suitable reactor systems and a monitoring and control strategy. The aim of this review is to provide an overview of halophilic microorganisms, principles of aromatic biodegradation, and sources of saline wastewater containing aromatics and other contaminants. Finally, process examples for halophilic wastewater treatment and potential process monitoring strategies are discussed. To further illustrate the significant potential of halophiles for saline wastewater treatment and to facilitate development of ready-to-implement processes, future research should focus on scale-up and innovative process monitoring and control strategies.

Assessment of the Efficiency of Aliquat 336+Rice Bran Oil for Separation of Acrylic Acid from Aqueous Solution Using Reactive Extraction

2018 ◽  
Vol 16 (9) ◽  
Author(s):  
Himangshu Mondal ◽  
Kanti Kumar Athankar ◽  
Kailas L. Wasewar
Keyword(s):  
Acrylic Acid ◽  
Rice Bran ◽  
Renewable Resources ◽  
Extraction Efficiency ◽  
Process Development ◽  
Rice Bran Oil ◽  
Reactive Extraction ◽  
Aliquat 336 ◽  
Proposed Model ◽  
Predicted Values

Abstract Biomass is an attractive target in process development for the emerging renewable resources based bio-refinery industry. Due to the ample range of application of acrylic acid, its production through bio-route received more awareness in scientific fraternity. In this view, an attempted was made to study the reactive extraction of acrylic acid with aliquat 336 in rice bran oil. Moreover, Box-Behnken matrix was employed to corroborate the effects of process variables viz. concentration of acrylic acid [CAA]aq, concentration of aliquat 336 [CR4N+Cl], and temperature on the extraction efficiency (η%). In physical extraction, average extraction efficiency was found in the order as: 43.55 > 35.36 > 29.14 at 303 K, 323 K, and 343 K respectively in rice bran oil. The correlation coefficient, R2 = 0.988 % indicates the appropriateness of proposed model to predict the extraction efficiency in terms of independent variables, and the predicted values were found in close agreement with that of experimental results. Further, R2(Pred) = 0.806 is in reasonable agreement with the R2(Adj) = 0.972. The optimum conditions for extraction of acrylic acid using aliquat 336 as an extractant in rice bran oil are [CAA]aq = 0.0.5 (mol/kg); [CR4N+Cl] = 1.98 (mol/kg); temperature = 323 K and the model predicted extraction efficiency 77.5 % was found to be an excellent fit with the experimental value 75 %. Further, number of theoretical stages was found to be 3 and S/F ratio 0.247.

Experimental and Kinetic Production of Ethanol Using Mucilage Juice Residues from Cocoa Processing

2018 ◽  
Vol 16 (11) ◽  
Author(s):  
Teresa Romero Cortes ◽  
Jaime A. Cuervo-Parra ◽  
Víctor José Robles-Olvera ◽  
Eduardo Rangel Cortes ◽  
Pablo A. López Pérez
Keyword(s):  
Ethanol Yield ◽  
Scale Up ◽  
Pilot Scale ◽  
Product Formation ◽  
Model Parameters ◽  
Pichia Kudriavzevii ◽  
Proposed Model ◽  
Analysis Of Results ◽  
Residual Plots ◽  
Kinetics Of

AbstractEthanol was produced using mucilage juice residues from processed cocoa with Pichia kudriavzevii in batch fermentation. Experimental results showed that maximum ethanol concentration was 13.8 g/L, ethanol yield was 0.50 g-ethanol/g glucose with a productivity of 0.25 g/L h. Likewise, a novel phenomenological model based on the mechanism of multiple parallel coupled reactions was used to describe the kinetics of substrate, enzyme, biomass and product formation. Model parameters were optimized by applying the Levenberg-Marquardt approach. Analysis of results was based on statistical metrics (such as confidence interval), sensitivity and by comparing calculated curves with the experimental data (residual plots). The efficacy of the proposed mathematical model was statistically evaluated using the dimensionless coefficient for efficiency. Results indicated that the proposed model can be applied as a way of augmenting bioethanol production from laboratory scale up to semi-pilot scale.

Intensification of the Production of 2-Ethyl-Hexyl Acrylate: Batch Kinetics and Reactive Distillation

2018 ◽  
Vol 16 (7) ◽  
Author(s):  
Vivek D. Talnikar ◽  
Onkar A. Deorukhkar ◽  
Amit Katariya ◽  
Yogesh S. Mahajan
Keyword(s):  
Kinetic Model ◽  
Acrylic Acid ◽  
Process Development ◽  
Reactive Distillation ◽  
Batch Reactor ◽  
Process Intensification ◽  
Complete Conversion ◽  
Reaction Conditions ◽  
Batch Mode ◽  
Batch Kinetics

Abstract The reaction of acrylic acid and 2-ethyl-1 hexanol was explored in this work with the intent of process intensification. In order to assess the effect of important parameters on the course of reaction, this work initially conducted batch reactor experiments. Reaction conditions in the batch reactor for a specific conversion (~ 30 %) were obtained. A kinetic model was then obtained through regression to arrive at a rate expression that is later used in process development. Experiments were performed in the reactive distillation (RD) environment in batch mode, which showed substantial increase in conversion (~ 80 %) indicating the applicability of RD. Further, this work performed simulation in the RD environment to assess process intensification. Simulations show that it is possible to obtain complete conversion of the acid.

Continuous Pilot-Scale Tubular Reactor for Acrylic Acid Polymerization in Solution Designed Using Lab-Scale Rheo-Raman data

2016 ◽  
Vol 10 (4) ◽  
pp. 354-363
Author(s):  
Marie-Claire Chevrel ◽  
Sandrine Hoppe ◽  
Dimitrios Meimaroglou ◽  
Laurent Falk ◽  
Alain Durand
Keyword(s):  
Acrylic Acid ◽  
Tubular Reactor ◽  
Pilot Scale
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