آنالیز حساسیت و بهینه سازی اقتصادی پیکربندی های چند مرحله ای غشایی برای جداسازی دی اکسید کربن از متان

Abstract

In this study, in order to perform a technical and economic comparative evaluation of membrane gas separation systems, six configurations consisting of single, two and three stages with permeate or waste return flow of membrane systems equipped with prefabricated membranes were simulated. These systems were designed for a case study of CO2 separation from CH4 in Aspen Plus environment and then the best configuration from an economic perspective was selected by short-cut economic calculations in the same software. This configuration was then transferred to MATLAB environment for more precise economic analyses. For this purpose, the permeability and selectivities of the prefabricated membranes used in the project were given as inputs to the MATLAB program and the output of the model, which was the purity of the exhaust gases and their recovery, was calculated. The global system performance index or IGP, which is simultaneously composed of the sum of the purity and the percentage of gas recovery, was calculated based on the process outputs. Using this index, the best membrane for the selected configuration was determined. Then, based on the physical and functional characteristics of the best sample, process economics calculations were performed and three key parameters Total costs, Capital costs and Operating costs were calculated. Based on the calculation of these parameters, it was determined that membranes with a lifespan of more than 2 years have lower replacement and maintenance costs and are more economically viable, due to the fact that the replacement costs are only a small part of the total system costs. Also, the optimal flow rate for membranes with a longer lifespan is about 1200 m3/h, due to the fact that at this flow rate, the total system cost is the lowest. As a result, using membranes with a long lifespan and adjusting the flow rate during this lifespan can improve the economic efficiency of the gas separation process.