Comparative Study of Membrane and Absorption Processes Performance and their Economic Evaluation for CO2 Capturing from Flue Gas

Document Type: Original Article

Authors

1 chemical engineering department, urmia university of technology, urmia, iran

2 Department of Chemical Engineering, University of Tehran, Tehran, Iran

3 chemical engineering fcalutly, zanjan university, Zanjan, Iran

4 ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, 87036 Rende (CS), Italy

Abstract

As main aim of this study, simulation and economic assessment of membrane technologies in comparison absorption process for CO2 capturing from a specified flue gas were conducted. For this purpose, the PRO/II v.10 software and Aspen Process Economic Analyzer v.10 were used. In this simulation, the flue gas flow rate is 8162 kmole/h and concentration of CO2 in flue gas is 8-22% mole. The objective function in simulation of CO2 capturing is to remove 85% of CO2 from the flue gas stream. The amount of required solvent and membrane surface as well as various costs such as equipment costs, installed costs, total capital cost, total utilities cost and total operating cost for different concentrations of CO2 in flue gas (8-22% mol.) was assessed for both membrane-based and absorption-based units. For CO2 selectivity and permeability values of 28 and 1097 barrer, respectively, the total capital cost in membrane-based process is very higher than absorption process. So that, the total capital cost of membrane unit was about 2.3 times higher than total capital cost of absorption process. In low concentration of CO2, the total utilities cost and total operating cost of membrane-based process was about 2.2 times higher than absorption process. However, by increasing the CO2 concentration the difference of these costs in two processes decreased. By analyzing the selectivity effects on the total capital costs, it is obtained that with selectivity value of 280 and the same permeability the costs of membrane-based process became comparable to the costs of absorption process.

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