Potential of Two-Stage Membrane System with Recycle Stream for CO₂Capture from Postcombustion Gas^†

Abstract

In order to restrict greenhouse gases emissions, CO 2 should be captured from the postcombustion gas for further treatment, for example, geosequestration. In this work, the separation performance of the twostage membrane system with a recycle stream was investigated using the cross-flow model. For larger CO 2 / N 2 selectivities that can be achieved in the lab, for example, selectivity of 52, the separation target of CO 2 purity >95% and CO 2 recovery >90% can be fulfilled by the two-stage system. The process cost of the two-stage membrane process was investigated. There is an optimum pressure ratio with which the capital cost and the energy cost can be balanced to minimize the total cost. Using the optimum pressure ratios and efficient membranes, the total cost of the two-stage system can be reduced to a range that is competitive with the process cost of the traditional chemical absorption method. For example, with feed compression applied, the total cost of the two-stage membrane system using the membrane with CO 2 /N 2 selectivity of 52 and CO 2 permeance of 3.12Â10 -3 m 3 (STP) m -2 s -1 MPa -1 is estimated to be $47.9/(ton CO 2 recovered).

High‐Performance Membranes with Multi‐permselectivity for CO2 Separation

“…This membrane shows promising application in CO 2 separation processes. It can be evaluated that by using the multi‐permselective membrane in the two‐stage membrane process,22 the high recovery and purity of the product can be achieved for the syngas and natural gas purification and the CO 2 capture from flue gas (Table S3 of the SI). In addition, the mixed‐gas selectivity decreases with increasing feed pressure as shown in Figure 2a, which is caused by the decrease in CO 2 permeance.…”

Improvement of CO2/N2 separation characteristics of polyvinylamine by modifying with ethylenediamine

“…Using the two-stage membrane system with a recycle stream, the minimum selectivity would decrease to 40 with the pressure ratio of 0.05 to fulfill the same separation target. Moreover, according to the analysis of the cost of the two-stage membrane system in our study [9], membranes with a relatively high CO 2 permeance and a moderate CO 2 /N 2 selectivity (e.g. CO 2 permeance of 410 GPU (1 GPU = 10 −6 cm 3 (STP)/cm 2 s cmHg) and CO 2 /N 2 selectivity of 52 or CO 2 permeance of 183 GPU and CO 2 /N 2 selectivity of 75) at the optimum pressure ratios can lower the total cost of membrane separation to compete with the chemical absorption method.…”

“…To define the feasible performance of polymer membrane that could meet the technoeconomical requirement of CO 2 capture, considerable research efforts have been made in recent years [4][5][6][7][8][9]. The simulation results in our study [9] showed that, to fulfill the separation target of CO 2 purity >95% and CO 2 recovery >90% from post-combustion gas (15% CO 2 in the gas), the minimum selectivity required for the single-stage membrane system is 300 under an extreme condition that the pressure ratio (the permeate pressure to the feed pressure) approaches 0. Using the two-stage membrane system with a recycle stream, the minimum selectivity would decrease to 40 with the pressure ratio of 0.05 to fulfill the same separation target.…”

Parametric analysis and potential prediction of membrane processes for hydrogen production and pre-combustion CO 2 capture

“…Models describing the spiral-wound membrane have been commonly used in previous studies, such as the cross-flow model, the cocurrent flow model and the countercurrent flow model. Comparing these results, the cross-flow model shows an intermediate result, and does not greatly differ from the results of the experiment in spiral-wound modules for flat membranes (Yang et al, 2009b). Consequently, the cross-flow model is reliably used as the mathematic module to compute the result for IGCC membrane systems.…”

“…Therefore, the membrane selectivity boundary has been dramatically extended, and the corresponding optimum operation conditions and potential usage for hydrogen purification should be calculated and evaluated. In previous studies, the CSM system membrane selectivity and permeance have often been analyzed independently (Yang et al, 2009b). Note that the product recovery is a function of product purity and membrane selectivity.…”