scholarly journals Multi-Objective Optimisation of Biodiesel Synthesis in Simulated Moving Bed Reactor

Separations ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 127
Author(s):  
Nillohit Mitra Ray ◽  
Ajay K. Ray
Keyword(s):  
Design Stage ◽  
Simulated Moving Bed ◽  
Moving Bed ◽  
Multi Objective ◽  
Design Variables ◽  
Biodiesel Synthesis ◽  
Single Column ◽  
Set Up ◽  
Yield And Purity ◽  
Selection Of

In this work, multi-objective optimisation study was performed to determine the performance improvement in a simulated moving bed reactor (SMBR) for biodiesel synthesis. The selection of the operating parameters such as switching time, liquid flow rates in various sections, as well as the length and number of columns is not straightforward in an SMBR. In most cases, conflicting requirements and constraints influence the optimal selection of the decision (operating or design) variables. A mathematical model that predicts single-column experimental results well was modified and verified experimentally for multiple-column SMBR system. In this article, a few multi-objective optimisation problems were carried out for both existing set-up as well as at the design stage. A non-dominated sorting genetic algorithm (NSGA) was used as the optimisation tool for the optimisation study. Due to conflicting effect of process parameters, the multi-objective optimisation study resulted in non-dominated Pareto optimal solutions. It was shown that significant increase in yield and purity of biodiesel in SMBR was possible both for operating and at design stage.

Multi-Objective Design Problem of Tire Wear and Visualization of Its Pareto Solutions2

2006 ◽  
Vol 34 (3) ◽  
pp. 170-194 ◽  
Author(s):  
M. Koishi ◽  
Z. Shida
Keyword(s):  
Inverse Problems ◽  
Conceptual Design ◽  
Dimensional Space ◽  
Design Stage ◽  
Objective Functions ◽  
Pareto Solutions ◽  
Design Problems ◽  
Multi Objective ◽  
Design Engineers ◽  
Design Variables

Abstract Since tires carry out many functions and many of them have tradeoffs, it is important to find the combination of design variables that satisfy well-balanced performance in conceptual design stage. To find a good design of tires is to solve the multi-objective design problems, i.e., inverse problems. However, due to the lack of suitable solution techniques, such problems are converted into a single-objective optimization problem before being solved. Therefore, it is difficult to find the Pareto solutions of multi-objective design problems of tires. Recently, multi-objective evolutionary algorithms have become popular in many fields to find the Pareto solutions. In this paper, we propose a design procedure to solve multi-objective design problems as the comprehensive solver of inverse problems. At first, a multi-objective genetic algorithm (MOGA) is employed to find the Pareto solutions of tire performance, which are in multi-dimensional space of objective functions. Response surface method is also used to evaluate objective functions in the optimization process and can reduce CPU time dramatically. In addition, a self-organizing map (SOM) proposed by Kohonen is used to map Pareto solutions from high-dimensional objective space onto two-dimensional space. Using SOM, design engineers see easily the Pareto solutions of tire performance and can find suitable design plans. The SOM can be considered as an inverse function that defines the relation between Pareto solutions and design variables. To demonstrate the procedure, tire tread design is conducted. The objective of design is to improve uneven wear and wear life for both the front tire and the rear tire of a passenger car. Wear performance is evaluated by finite element analysis (FEA). Response surface is obtained by the design of experiments and FEA. Using both MOGA and SOM, we obtain a map of Pareto solutions. We can find suitable design plans that satisfy well-balanced performance on the map called “multi-performance map.” It helps tire design engineers to make their decision in conceptual design stage.

Single-column simulated-moving-bed process with recycle lag

AIChE Journal ◽  
2005 ◽  
Vol 51 (6) ◽  
pp. 1641-1653 ◽  
Author(s):  
José P. B. Mota ◽  
João M. M. Araújo
Keyword(s):  
Simulated Moving Bed ◽  
Moving Bed ◽  
Single Column

Robustness of Design Through Minimum Sensitivity

1992 ◽  
Vol 114 (2) ◽  
pp. 213-217 ◽  
Author(s):  
A. D. Belegundu ◽  
Shenghua Zhang
Keyword(s):  
Optimization Problem ◽  
Probability Distributions ◽  
Uncertain Variable ◽  
Design Stage ◽  
Cross Sectional ◽  
Uncertain Variables ◽  
Design Variables ◽  
Variable Reduction ◽  
Minimum Sensitivity ◽  
Selection Of

The problem of designing mechanical systems or components under uncertainty is considered. The basic idea is to ensure quality control at the design stage by minimizing sensitivity of the response to uncertain variables by proper selection of design variables. The formulation does not involve probability distributions. It is proved, however, that when the response is linear in the uncertain variable, reduction in sensitivity implies lesser probability of failure. The proof is generalized to the non-linear case under certain restrictions. In one example, the design of a three-bar truss is considered. The length of one of the bars is considered to be the uncertain variable while cross-sectional areas are the design variables. The sensitivity of the x-displacement is minimized. The constrained optimization problem is solved using a nonlinear programming code. A criterion which can help identify some of the problems where robustness in design is critical is discussed.

scholarly journals Single-Column Simulated Moving-Bed Process with Recycle Lag: Analysis and Applications

2007 ◽  
Vol 25 (9) ◽  
pp. 647-659 ◽  
Author(s):  
João M.M. Araújo ◽  
Rui C.R. Rodrigues ◽  
Ricardo J.S. Silva ◽  
José P.B. Mota
Keyword(s):  
Simulated Moving Bed ◽  
Moving Bed ◽  
Single Column

Inverse Stochastic Routine Combined to a Stepwise Modeling Approach in the Chromatographic Column Characterization Applied to Simulated Moving Bed-SMB Separation of Verapamil Enantiomers

2017 ◽  
Vol 372 ◽  
pp. 101-109
Author(s):  
Anderson Luis Jeske Bihain ◽  
Pedro Castro Menezes Xavier de Mello e Silva ◽  
Everton Mendes de Oliveira ◽  
Leandro Blass ◽  
Antônio José da Silva Neto ◽  
...  
Keyword(s):  
Separation Process ◽  
Chromatographic Behavior ◽  
Simulated Moving Bed ◽  
Residence Times ◽  
Moving Bed ◽  
Modeling Approach ◽  
Chromatographic Columns ◽  
Good Potential ◽  
Transfer Parameters ◽  
Set Up

Simulated Moving Bed (SMB) chromatographic processes for the enantiomers separation of the drug verapamil were evaluated through stepwise modeling approach. Predictions of the model were compared to the dispersive equilibrium model in the simulation of continuous separation process and validated with data taken for both compounds in a SMB experimental set-up. An inverse problem tool was associated to the chromatographic columns aiming at their characterization through the global mass transfer parameters using only the experimental residence times of each enantiomer. According to the study conducted, the proposed approach was shown to be a tool with a good potential to predict the chromatographic behavior of a sample in a test pulse, as well as the simulation of separation of a compound in SMB equipment despite minor discrepancies presented in the first work cycles of the SMB. Moreover, the approach can be easily implemented and applied in the analysis of the process.

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