Dynamics of semibatch polymerization reactors: II. Pilot‐plant study

Chylla, Richard W.; Campbell, J. D.; Teymour, Fouad

doi:10.1002/aic.690430118

Cited by 5 publications

(3 citation statements)

References 1 publication

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“…Ellis et al (1994) obtained good experimental results for the estimation of the molecular weight distribution (MWD) in a batch polymerization reactor by using online densitometer and online size exclusion chromatograph (SEC), and then controlled the polymer quality with a PID controller. The application of online measurement devices has also been reported in other research works (Echevarria et al, 1998;Chylla et al, 1997;Chang and Liao, 1999) and an excellent review on the online measurement techniques has been presented by Ohshima and Tanigaki (2000).…”

Section: Introductionmentioning

confidence: 94%

Online estimation and control of polymer quality in a copolymerization reactor

2002

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The validity of an online state estimator for a semi-batch IntroductionCopolymer has a variety of better properties than homopolymer, because two monomers having different characteristics are used to compose the structure of a polymer chain. However, the use of two monomers brings about a greater complexity and requires several factors to be determined for the production of copolymers with desired end-user properties. Hence, a great deal of research interest has been focused on the development of the operation technique for the control of these factors.Copolymer composition is one of the most important factors that affect the properties of copolymer. It is well known that copolymer composition drift occurs in a batch or semibatch free radical copolymerization reactor due to the different reactivities of two monomers. Choi and Butala (1989) proposed open-loop control policies for both molecular weight and copolymer composition by using an inverse feedback control method. On the other hand, Kozub and MacGregor (1992a) applied the optimal instantaneous property Correspondence concerning this article should be addressed to H.-K. Rhee. condition in such a way that the instantaneous polymer being produced at every instant of time might have the desired properties. This method, which has been used by many researchers in recent years (Saldivar and Ray, 1997; Sayer et al., 20001, suffers from several features such as the existence of disturbances appearing in most chemical reactors, or mismatches between the real system and the model used for the calculation of optimal trajectory.To overcome these difficulties, offline measurements or online measurements with time delay were used to update the optimal trajectory. A midcourse correction policy was employed by Yabuki and MacGregor (1997), who used online measurement of the reactor temperature and offline measurements of the residual monomer concentration by gas chromatography and the volume average particle sue by dynamic light scattering in order to make the midcourse adjustment. Gattu and Zafiriou (1999) used the temperature as the primary measurement and the average molecular weights and conversion as the secondary measurements.As reported by Congalidis and Richards (1998), polymerization reactors lack the online measurements of polymer properties and this has been the major obstacle in the appli-1013 AIChE Journal cation of control strategies to industrial reactors. To make an estimation for the state of a polymerization reactor, Dimitratos et al. (1989Dimitratos et al. ( , 1991 implemented the conventional extended Kalman filter (EKF) to the semicontinuous emulsion copolymerization reactor and developed a filter with parameter adaptation and noise adaptation algorithms. Kozub and MacGregor (1992b) augmented the EKF with a second EKF to improve the convergence, whereas Kazantzis et al. (2000) designed the model based nonlinear observer for process monitoring.Recently, the development of online measurement devices such as a densitometer, a calorimeter, and a viscomet...

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Section: Introductionmentioning

confidence: 94%

Online estimation and control of polymer quality in a copolymerization reactor

2002

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“…Olaj and Schnoll-Bitai 22) extended their work on penultimate schemes from copolymerization to terpolymerization, whereas Schoonbrood et al 23) argued on behalf of the penultimate effect for the terpolymerization of styrene/methyl methacrylate/methyl acrylate, studied via pulsed laser techniques. Finally, Chylla et al 24) looked at semi-batch flow scheduling strategies and related practical considerations for the terpolymerization of styrene/ a-methyl styrene/acrylic acid.…”

Section: Brief Background On Terpolymerizationmentioning

confidence: 99%

A comprehensive simulator/database package for bulk/solution free-radical terpolymerizations

Gao

Penlidis

2000

Macromol. Chem. Phys.

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Terpolymerizations in bulk/solution over the entire conversion range are investigated in detail via a general mathematical model and a comprehensive simulator/database package. The model and simulator are extensions to terpolymerizations (multicomponent polymerizations) of models described previously in Gao and Penlidis (cf. ref.1, 2)) for free‐radical homopolymerizations and copolymerizations in bulk/solution. Experimental data for terpolymerizations in bulk/solution over the full conversion range are very limited (if non‐existent) in the literature. Testing has been performed with the very challenging and commercially used system of butyl acrylate/methyl methacrylate/vinyl acetate in bulk and toluene solution.

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“…Contrary to block copolymers with analogous compositions, that can also stabilize latexes, the implementation in industrial processes is more straightforward, and common free radical polymerization techniques are suitable. Solution polymerization [ 18 ], bulk polymerization [ 19 , 20 ] and emulsion polymerization [ 21 , 22 ] can be chosen as alternatives to produce ASRs with different acid values (AVs), molecular weights and compositions. The last strategy, in particular, represents a very interesting option; the synthesis of the resin can be conducted in-situ in a stirred tank reactor through a conventional emulsion (semi) batch process.…”

Section: Introductionmentioning

confidence: 99%

One-Pot Synthesis of Waterborne Polymeric Dispersions Stabilized with Alkali-Soluble Resins

2018

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Alkali-soluble resins (ASRs) are a type of electrosteric emulsifiers of high interest because they can profitably improve the features of waterborne dispersions. In this work, they have been synthesized in-situ through a one-pot approach and they have been used as polymeric surfactants for a second emulsion polymerization step in the same reactor. This strategy provides some advantages compared to other polymerization techniques, like the intensification of the process and the absence of organic solvents. Their use can also further reduce the environmental impact of formulations for film-forming applications, since grafting reactions with the particles have been observed and quantified in relation with the synthetic parameters. These chemical linkages with the particles may reduce the leaching and the release of surfactants from polymeric films, for example in water-based coatings or adhesives. The systems have been also studied from the kinetics point of view, finding relevant differences with other electrosterically stabilized processes from the literature, as well as concerns the nucleation mechanism.

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Dynamics of semibatch polymerization reactors: II. Pilot‐plant study

Abstract: A semibatch flow scheduling strategy proposed by Teymour and Ray (1989, 1996)

Cited by 5 publications

References 1 publication

Online estimation and control of polymer quality in a copolymerization reactor

Online estimation and control of polymer quality in a copolymerization reactor

A comprehensive simulator/database package for bulk/solution free-radical terpolymerizations

One-Pot Synthesis of Waterborne Polymeric Dispersions Stabilized with Alkali-Soluble Resins

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