Implementation of CHAMEN by means of Passivity Concept on Methanol Solvent Process

This article mainly focuses on the application of the combined heat and mass exchanger network (CHAMEN) on Methanol solvent process. CHAMEN analyses heat exchanger network (HEN) and mass exchange network (MEN); simultaneously. HEN was designed by Aspen Energy Analyzer, while MEN was analyzed by GAMS. Then, optimal controllers were designed by the passivity concept to guarantee the general process stability. The dynamic model was generated for all variables of the unit in the state space domain. Subsequently, the state space model of CHAMEN was formulated investigated by the concept of passivity. Analyses by the passivity index can indicate the passivity of process. Also, this process with HEN and CHAMEN was investigated the performance of the system with and without controllers. Moreover, the responsibility of controllers was analyzed based on the concept of passivity and compared with auto tune method by Aspen Dynamic. Likewise, the passivity tune presented the better robust control over conservation method by auto tune. Finally, we explored future challenges in this field of apply to another process.Â

Interval Based MINLP Superstructure Synthesis of Multi-Period Mass Exchanger Networks

A new method for the synthesis of mass exchanger networks for multi-period operations is presented in this paper. The new technique which is called multi-period interval based MINLP superstructure (MIBMS) for mass exchange network synthesis (MENS) is adapted from the interval based MINLP superstructure for MENs presented by Isafiade and Fraser (2008). Process parameters such as supply and target compositions and flowrates of streams can vary over a specified range due to environmental or economic reasons. In this paper, the IBMS model for MENS is modified to handle variations in the aforementioned set of parameters by including the index ‘p' in the IBMS model and using the maximum area approach in the objective function as presented by Verheyen and Zhang (2006) for multi-period heat exchanger networks synthesis (HENS). The index ‘p' represents each period of operation which in this paper can be unequal. The maximum area approach ensures that each mass exchanger connecting the same pair of streams in more than one period is able to transfer mass in such streams for all the periods. It should be known that this technique applies to multi-period problems where the process parameters for each period of operation as well as the duration are specified. The method does not handle scenarios where the process parameters are uncertain. The new technique is applied to three examples.