Uncertainties in parameter estimation and optimal control in batch distillation

Ulas, Saadet; Diwekar, Urmila M.; Stadtherr, Mark A.

doi:10.1016/j.compchemeng.2005.03.002

Cited by 23 publications

(19 citation statements)

References 6 publications

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“…For example, Ulas et al [52] demonstrate how batch distillation optimal control profiles are affected by using the globally optimal parameter values predicted by IN/GB, versus the locally optimal parameters published in DECHEMA. Since batch distillation is a dynamic process, the uncertainties in model parameters are translated into time-dependent uncertainties.…”

Section: Resultsmentioning

confidence: 98%

Reliable Modeling and Optimization for Chemical Engineering Applications: Interval Analysis Approach

2006

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In many applications of interest in chemical engineering it is necessary to deal with nonlinear models of complex physical phenomena, on scales ranging from the macroscopic to the molecular. Frequently these are problems that require solving a nonlinear equation system and/or finding the global optimum of a nonconvex function. Thus, the reliability with which these computations can be done is often an important issue. Interval analysis provides tools with which these reliability issues can be addressed, allowing such problems to be solved with complete certainty. This paper will focus on three types of applications: 1) parameter estimation in the modeling of phase equilibrium, including the implications of using locally vs. globally optimal parameters in subsequent computations; 2) nonlinear dynamics, in particular the location of equilibrium states and bifurcations of equilibria in ecosystem models used to assess the risk associated with the introduction of new chemicals into the environment; 3) molecular modeling, with focus on transition state analysis of the diffusion of a sorbate molecule in a zeolite.

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Section: Resultsmentioning

confidence: 98%

Reliable Modeling and Optimization for Chemical Engineering Applications: Interval Analysis Approach

2006

Self Cite

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“…Previously, the work done in our group on uncertainty characterization and modeling has revealed that the Ito processes are quite efficient in capturing the time-dependent uncertainties in batch processes (Ulas et al, 2005;Benavides and Diwekar, 2012;Yenkie and Diwekar, 2013). Also, they were equally efficient in capturing the time-dependent variations in the blood glucose levels of insulin-dependent diabetes patients (Ulas and Diwekar, 2010).…”

Section: Introductionmentioning

confidence: 98%

Uncertainty in clinical data and stochastic model for in vitro fertilization

Yenkie

Diwekar

2015

Journal of Theoretical Biology

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“…Ulas et al 28 and Ulas and Diwekar 29 have concluded that a good dynamic behavior in distillation can only be obtained if the effects of thermodynamic uncertainties are minimized. The effect of uncertainties due to the usage of local methods during the parameter estimation step in VLE modeling propagated the dynamic response of the equipment.…”

Section: Control Properties Analysismentioning

confidence: 99%

“…The high nonlinearity of the problem of parameters estimation suggests that only global optimization techniques should be used; however, in most of the cases, the estimation is based on a least-squares or maximum likelihood analysis. 3 For instance, Gau et al 4 found that for some of the equilibrium data published in the Dechema Collection, the adjusted parameters are just local optima. This finding is very important, because design, simulation, optimization, and even control of the reactive and separation process rely on estimation of thermodynamic properties, especially the phase equilibrium.…”

Section: Introductionmentioning

confidence: 99%

“…In most of the cases, the objective function in nonlinear parameter estimation is nonconvex, and it may have multiple local optima. 3 Therefore, assuming that experimental equilibrium data are thermodynamically consistent, it is clear that the use of different methods to realize the nonlinear regression will affect the resulting adjusted parameters, and, as a consequence, the predicted phase equilibrium. The high nonlinearity of the problem of parameters estimation suggests that only global optimization techniques should be used; however, in most of the cases, the estimation is based on a least-squares or maximum likelihood analysis.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Using Adjusted Parameters, Local and Global Optimums, for Phase Equilibrium Prediction on the Synthesis of Azeotropic Distillation Columns

Gutiérrez‐Antonio

Ojeda-Gasca

Bonilla-Petriciolet

et al. 2014

Ind. Eng. Chem. Res.

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ABSTRACT:We analyze the effect of using adjusted parameters, corresponding to local and global optimums, in the NRTL thermodynamic model on the complete process synthesis (design, optimization and control) of homogeneous azeotropic distillation columns. The adjusted parameters that correspond to a global optimum were obtained with simulated annealing technique, while the adjusted parameters that correspond to a local optimum were taken from the Dechema Collection. Both sets of parameters were used to design a conventional sequence, a side-stream column, and a Petlyuk sequence. These designs were used as the initial solution to a multiobjective genetic algorithm with constraints handling, coupled to a processes simulator, where the number of stages and heat duty of each column were considered as objectives; as a result, a set of optimal designs, called the Pareto front, was obtained. Then, we chose some designs to analyze their theoretical control properties and the dynamic performance. Results show remarkable differences in structure, energy consumption, control properties, and dynamic performance of these schemes, depending on the use of adjusted parameters. The results show the importance of using the best adjusted parameters available, which in our case correspond to global optimums obtained with the simulated annealing technique.

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Uncertainties in parameter estimation and optimal control in batch distillation

Cited by 23 publications

References 6 publications

Reliable Modeling and Optimization for Chemical Engineering Applications: Interval Analysis Approach

Reliable Modeling and Optimization for Chemical Engineering Applications: Interval Analysis Approach

Uncertainty in clinical data and stochastic model for in vitro fertilization

Effect of Using Adjusted Parameters, Local and Global Optimums, for Phase Equilibrium Prediction on the Synthesis of Azeotropic Distillation Columns

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