The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

Claus J H Jacobsen - One of the best experts on this subject based on the ideXlab platform.

Claus Madsen - One of the best experts on this subject based on the ideXlab platform.

J. A. Romagnoli - One of the best experts on this subject based on the ideXlab platform.

  • a generalized stochastic modelling approach for Crystal Size Distribution in antisolvent Crystallization operations
    Aiche Journal, 2017
    Co-Authors: R. Baratti, Stefania Tronci, J. A. Romagnoli
    Abstract:

    A generalized formulation for the development of stochastic models to predict the Crystal Size Distribution (CSD) in antisolvent Crystallization processes is proposed. Exploiting the result of the noise induced dynamic in stochastic processes, new results are provided to represent the CSD as function of the operational parameters. The generalized formulation enables the full description of the CSD using nonlinear drift term in conjunction with multiplicative noise, i.e., state dependent diffusion. For the first time a deterministic nonlinear differential equation to represent the mean and most probable Size (mode) time evolution as function of the model parameters is provided. Furthermore, the analytical solution of the asymptotic probability Distribution of the CSD can also be obtained. Finally, a global model formulation is finally presented by defining relationships between the model parameters and the operating conditions. Experimental results and validations are provided using the ternary system of NaCl, water, and ethanol. © 2016 American Institute of Chemical Engineers AIChE J, 63: 551–559, 2017

  • A Stochastic Formulation for the Description of the Crystal Size Distribution in Antisolvent Crystallization Processes
    Aiche Journal, 2009
    Co-Authors: M. Grosso, O. Galan, R. Baratti, J. A. Romagnoli
    Abstract:

    A stochastic approach to describe the Crystal Size Distribution dynamics in antisolvent based Crystal growth processes is here introduced. Fluctuations in the process dynamics are taken into account by embedding a deterministic model into a Fokker-Planck equation, which describes the evolution in time of the particle Size Distribution. The deterministic model used in this application is based on the logistic model, which shows to be adequate to suit the dynamics characteristic of the growth process. Validations against experimental data are presented for the NaCl–water–ethanol antisolvent Crystallization system in a bench-scale fed-batch Crystallization unit. © 2009 American Institute of Chemical Engineers AIChE J, 2010

  • A stochastic formulation for the description of the Crystal Size Distribution in antisolvent Crystallization processes
    AIChE Journal, 2009
    Co-Authors: M. Grosso, O. Galan, R. Baratti, J. A. Romagnoli
    Abstract:

    A stochastic approach to describe the Crystal Size Distribution dynamics in antisolvent based Crystal growth processes is here introduced. Fluctuations in the process dynamics are taken into account by embedding a deterministic model into a Fokker-Planck equation, which describes the evolution in time of the particle Size Distribution. The deterministic model used in this application is based on the logistic model, which shows to be adequate to suit the dynamics characteristic of the growth process. Validations against experimental data are presented for the NaCl-water-ethanol antisolvent Crystallization system in a bench-scale fed-batch Crystallization unit

Do Hyun Kim - One of the best experts on this subject based on the ideXlab platform.

  • control of Crystal Size Distribution using non isothermal taylor vortex flow
    Crystal Growth & Design, 2015
    Co-Authors: Seunghwan Seok, Do Hyun Kim
    Abstract:

    Using a Couette-Taylor (CT) Crystallizer, a non-isothermal technique was developed for effective control of the Crystal Size Distribution (CSD) of the suspension. The proposed technique is based on the internal heating–cooling cycle in a non-isothermal CT Crystallizer, consisting of a hot cylinder (Th) and cold cylinder (Tc). Thus, an internal loop of fines destruction of the suspension in the heating boundary layer of the hot cylinder and reCrystallization in the cooling boundary layer of the cold cylinder is formed by the periodic circulating flow of the Taylor vortex in the non-isothermal CT Crystallizer. The efficiency of the heating–cooling cycle for improving the CSD depends on the non-isothermal mode and non-isothermal parameters. When the inner cylinder temperature is hot and the outer cylinder temperature is cold (Mode-I), this is more efficient for improving the mean Crystal Size and dispersity of the CSD than when the cylinder temperatures are reversed (Mode-II). In addition, the efficiency of ...

Richard D. Braatz - One of the best experts on this subject based on the ideXlab platform.

  • multiscale modeling and simulation of macromixing micromixing and Crystal Size Distribution in radial mixers Crystallizers
    Industrial & Engineering Chemistry Research, 2018
    Co-Authors: Cezar A Da Rosa, Richard D. Braatz
    Abstract:

    Continuous-flow tubular Crystallization in which seed Crystals are continuously generated is of interest due to its enabling of tighter control of Crystal properties. This article is the most detailed simulation study on the design and operation of continuous-flow Crystallizers using radial mixers, which have potential for inducing rapid and intense turbulent mixing and having easy construction, high reliability, and low operating costs. A multiscale model is employed that couples computational fluid dynamics (CFD), micromixing modeling, energy balance, and population balance equation (PBE) using the open-source CFD package OpenFOAM. The approach is demonstrated for the methanol–water antisolvent Crystallization of lovastatin. A new Crystallizer design with multiple radial inlets is proposed and shown to deliver improved mixing compared to one radial inlet. The effects of varying operating conditions on micromixing and Crystal Size Distribution are analyzed. A systematic approach is provided for the desig...

  • effect of jet velocity on Crystal Size Distribution from antisolvent and cooling Crystallizations in a dual impinging jet mixer
    Chemical Engineering and Processing, 2015
    Co-Authors: Mo Jiang, Yaoen David Li, Hsienhsin Tung, Richard D. Braatz
    Abstract:

    Abstract In the pharmaceutical industry, good control of the Crystal Size Distribution (CSD) can improve process efficiency and formulation of the drug product. An effective method to continuously generate small Crystals of narrow Size Distribution for some drug/solvent systems is by using a dual-impinging jet (DIJ) mixer. This paper demonstrates the first use of a DIJ mixer combining cooling and antisolvent Crystallization to generate Crystals with a typical pharmaceutical solubility. In a confined Y-shaped DIJ mixer by this approach, product Crystals are obtained with smaller Sizes and aspect ratios than a conventional batch process. We also quantify the relationships between the particle Size, Distribution width, and Distribution modality on the inlet jet velocity. This combination of cooling and antisolvent Crystallization may widen the application of DIJ mixers for the generation of small uniform pharmaceutical Crystals.

  • precise tailoring of the Crystal Size Distribution by controlled growth and continuous seeding from impinging jet Crystallizers
    CrystEngComm, 2011
    Co-Authors: Richard D. Braatz
    Abstract:

    The desired bioavailability and the method of drug administration and delivery can require stringent control on the Crystal Size Distribution. Optimal control strategies are proposed to manufacture Crystals with a targeted Size Distribution by combining controlled seeding by impinging jet Crystallization with a batch Crystallizer operating at a controlled constant growth rate. The same strategies apply if the impinging jet Crystallization is replaced by any process equipment that can continuously provide Crystal seeds, typically through the application of high supersaturation, to the batch Crystallizer. Limitations to the achievable Crystal Size Distributions and sensitivity to process operations are analyzed. Simulation results indicate that one of the strategies has promise for manufacturing pharmaceutical Crystals of a desired Size Distribution.

  • Developing a Systematic Design Approach to Tailor Crystal Size Distribution for Mixing-Sensitive Crystallization Processes
    2006
    Co-Authors: Xing Yi Woo, Reginald B. H. Tan, Richard D. Braatz
    Abstract:

    The design of Crystallization processes becomes more complicated when mixing affects the final Crystal product quality (e.g., Crystal Size Distribution and polymorphic form). Such mixing effects are more apparent in antisolvent and reactive Crystallizations, which involve the blending of different fluids, and in large-scale Crystallizers, where homogeneity cannot be easily achieved. In this paper, we present the use of an integrated algorithm, which couples macromixing and micromixing models with the population balance equation, to model antisolvent Crystallization in a stirred vessel and impinging jet Crystallizers. The dependency of the Crystal Size Distribution on the mixing speed and scale for a stirred vessel and the effects of jet velocity on the Crystal Size Distribution and polymorphic form for an impinging jet Crystallizer are numerically investigated. Eventually, the development of such computational tools would enable us to understand the interactions between hydrodynamics and the kinetics of Crystallization in order to develop systematic design methodologies for Crystallization processes.