วรัญญา เห็นวัฒนะ. Development of a Mass Exchange Networks (MENs) Module for Aspen Plus . Master's Degree(Chemical Engineering). King Mongkut's University of Technology Thonburi. : King Mongkut's University of Technology Thonburi, 2006.
Development of a Mass Exchange Networks (MENs) Module for Aspen Plus
การพัฒนาโปรแกรมการออกแบบเครือข่ายแลกเปลี่ยนมวลสำหรับโปรแกรม Aspen Plus
Abstract:
The optimum water usage network leads to a minimum freshwater consumption resulting in a minimum of consequently
generated wastewater. This work is to develop of a mass exchange networks (MENs) module for minimum freshwater
usage target. This module was developed as an interface to retrieve supplemental data of a chemical process from Aspen
Plus and to communicate to the genetic algorithm optimizer based on Detchasits work [11]. In this work, reuse system
and regeneration recycle system with only single contaminant are considered as approaches for freshwater minimization
and formulated as a mixed integer nonlinear programming (MINLP). In this model, all of variables are divided into 2 groups;
independent and dependent variables. The values of independent variables come from randomization whereas the values of
dependent variables come from simultaneous solutions of a set of equality constraints after assigning the values of independent
variables. This method is applied to the steps of Initialization, Crossover and Mutation. The MENs module is tested with two
chemical processes; 1) a tricresyl phosphate process that contains five unit operations in which water is used to remove a fixed
content of cresol, and 2) an ethyl chloride process that contains two unit operations in which water is used to remove a fixed
content of chloroethanol. From the result, the module gives the reliable solution for freshwater minimization. The solution from
the module can satisfy mass balance and constraints. The results also agree with the theory that the reuse and the regeneration
recycle can reduce the freshwater consumption including wastewater generated but reuse cannot decrease the mass load of
contaminant while regeneration recycle can. Regenerator can save the freshwater more than reuse but a company has to consider
effect investment cost. Moreover, the module is general for any chemical processes and it can decrease time consuming and give
convenience to calculate the input for freshwater minimization.