Optimal operation of a continuous DTB crystallizer

Hasebe, Shinji; Hamamura, Takashi; Naito, Kazuki; Sotowa, Ken‐Ichiro; Kano, Manabu; Hashimoto, Iori; Betsuyaku, Hitoshi; Takeda, Hironobu

doi:10.1016/s0959-1524(00)00019-6

Cited by 9 publications

(6 citation statements)

References 10 publications

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“…In order to get more relevant and in-depth data on the development of crystallization processes in the presence of impurities, new sensing technologies are highly valuable because they can provide continuous in situ data on both the continuous and the dispersed phases. During the past decade, was obviously unavailable when the pioneering control works and the textbooks quoted above were published (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) .…”

Section: Impurities and Industrial Batch Cooling Crystallization Procmentioning

confidence: 99%

“…Starting from the basic kinetic framework defined by Eqs. (3)(4)(5) and PBEs (10)(11)(12), the possibility of obtaining multiple supersaturation bumps with varying kinetic parameters was evaluated for a wide range of values. The reference values of the parameters involved by eqs.…”

Section: Simulation Of Crystallizations In Pure Solvent Exhibiting Prmentioning

confidence: 99%

“…The dynamics presented in Figure a was neither irrefutably explained nor proved in the literature, and no convincing experimental results are actually published that would demonstrate the onset of repeated supersaturation bumps during uncontrolled cooling crystallization operations. In fact, to the best of our knowledge, concentration profiles like the one shown in Figure a were never reported in the case of batch operations, while the existence of MNBs leading to oscillatory behaviors of crystallizers was clearly established and thoroughly analyzed in the case of continuous processes. − It is suggested below that supersaturation oscillations are implausible when pure solvents are used, even when multiple nucleation events take place. A clear distinction will thus be made in the following between MNBs and supersaturation oscillations which, for the sake of clarity, will be referred below to as oscillatory supersaturation dynamics (OSD).…”

Section: Introductionmentioning

confidence: 96%

“…This is how the acquisition of supersaturation measurements during the present work provided new information about the existence of oscillatory concentration trajectories. Indeed, in-line refined experimental information was obviously unavailable when the pioneering control works and the textbooks quoted above were published. − …”

Section: Introductionmentioning

confidence: 99%

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On Multiple Nucleation Bursts During Solution Crystallization in Pure and Impure Solvent

Févotte

Gherras

2012

Crystal Growth & Design

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It is widely accepted that during batch cooling crystallization processes, uncontrolled cooling can produce multiple nucleation events which have a detrimental effects on the Crystal Sizes Distributions (CSD). Controlling the CSD therefore requires mastering nucleation during the whole batch development: this is the starting point of many studies devoted to temperature control during industrial crystallization operations. When nucleation phenomena take place throughout the batch process; the time allocated to every crystal to grow is widespread, which enlarges the width of final CSD. Successive nucleation phenomena are referred below to as "Multiple Nucleation Bursts (MNB)". Oscillatory Supersaturation Dynamics (OSD) are sometimes assumed to accompany the trend of multiple nucleation bursts and it is suggested in the following that MNBs should not be misread as oscillatory supersaturation profiles. Experimental results obtained during the crystallization of ammonium oxalate in the presence of impurities (NiSO 4) are presented to support and illustrate OSDs crystallizations which, even though they are often presented as a basic pattern of uncontrolled batch crystallization systems, were never observed before. A PBE simulation model based on Kubota-Mullin's pinning mechanism is developed to represent the observed oscillations of supersaturation. The latter are shown to be rather likely when inhibiting impurities are present in solution, but it is suggested that oscillations of supersaturation are unlikely in pure solvents. These latter two results shed some new light on the need of controlling temperature during batch cooling crystallization processes.

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Section: Impurities and Industrial Batch Cooling Crystallization Procmentioning

confidence: 99%

Section: Simulation Of Crystallizations In Pure Solvent Exhibiting Prmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On Multiple Nucleation Bursts During Solution Crystallization in Pure and Impure Solvent

Févotte

Gherras

2012

Crystal Growth & Design

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“…There is much research about calculation methods to solve the multidimensional PB model. One work concluded by some researchers as an appropriate method, in terms of accuracy and short computing time, is “method of characteristic”. , In this study, CIP method , was used. CIP method is a kind of “method of characteristic” and was originally developed to solve the advection equation that includes population balance equation.…”

Section: Calculation Methods and Conditionsmentioning

confidence: 99%

The Application of Two-Dimensional Population Balance Model To Study the Effect of Temperature Profile on the Crystal Size Distribution and Aspect Ratio

Shoji

Takiyama

2012

Crystal Growth & Design

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The effect of cooling profiles on the average crystal size and aspect ratio was studied as an example of the application of two-dimensional population balance model. The nonseeded cooling type batch crystallization system was chosen for this study. The simulation successfully provided the information about the crystal size distribution and the average aspect ratio of each crystal product obtained through different cooling profiles. In addition, using the proposed model, it was expected that the modulate cooling in which undersaturation is introduced during the cooling operation, that has already been reported in previous research as an effective method to improve crystal size distribution, is also applicable for the improvement of aspect ratio. However, it was also implied that the results were influenced by various factors such as nucleation rates, growth rates, and dissolution rates of length and width.

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