Efficient Simulation of Batch Distillation Processes by Using Orthogonal Collocation

Abstract

Orthogonal collocation on finite elements is applied to discretize the DAE system for the simulation of multiple-fraction batch distillation processes. A detailed dynamic tray-by-tray model is used to describe batch columns more accurately which, however, leads to a set of model equations composed of nonlinear DAEs with a fairly high dimension. In addition, batch distillation operation usually takes a long period of time and therefore it costs large computational expense to simulate such processes. The use of orthogonal collocation is demonstrated to obtain a stable and highly accurate algebraic representation of the differential equations so as to improve the computational efficiency significantly. Because of the orthogonality of the polynomials introduced to approximate the state variables within a time interval, large integration steps can be taken with the collocation approximation without reducing the computational accuracy. Through simulation of two real batch distillation processes it is found that with this discretization approach 50% CPU time can be saved in comparison to the implicit Euler method normally used.

Operational Optimization of Batch Distillation Systems

“…17 Rigorous models of batch rectifiers containing differential mass balance equations and differential or algebraic energy balance equations were used for simulation and optimization studies. 3,6,7,9,18,19 Kreul et al 20 presented a rate-based model for multicomponent batch rectifiers. Along with the conventional batch rectifier, nonconventional or novel batch distillation columns have also been modeled.…”

“…More rigorous models for multicomponent batch rectifiers based on stage-by-stage mass balance calculations were used by Noda et al, Farhat et al, Mayur and Jackson, Domenech and Enjalbert, Galindez and Fredenslund, and Bonny . Rigorous models of batch rectifiers containing differential mass balance equations and differential or algebraic energy balance equations were used for simulation and optimization studies. ,,,,, Kreul et al presented a rate-based model for multicomponent batch rectifiers.…”

Rotational molding of self‐hybrid composites based on linear low‐density polyethylene and maple fibers

“…For example, Panthapulakkal and Sain [10] reported that tensile strength and tensile modulus increased by 13% and 17% for hemp and glass fibers in polypropylene (PP) produced by injection molding. In another study [11], the authors reported that thermomechanical pulp fibers (40% wt.) with 10% wt.…”

Neural Network Control for a Batch Distillation Column

“…The choice of the type of operation of distillation, as batch or continuous depends on the feed amount and on the characteristics of the feed components. The batch distillation is more commonly used due to its convenience for low volume, fine chemicals and bio chemicals [2], and its advantages like "flexibility, high product purity and possibility of multiple fraction operation [3].…”