Perspective on Gas Separation Membrane Materials from Process Economics Point of View

Abstract

Gas separation membranes are expected to play a significant role in green house reduction, renewable energy production, and energy savings for separations. However, newly developed membrane materials are constrained by the trade-off between selectivity and permeability and existing body of literature lacks the clear guidance on directions for the investigation. In this paper, we first systematically reviewed the effects of mixed gases and contaminants on membrane selectivities from gas transport mechanism. We then examined cascade membrane process design to achieve the desired product recovery and purity, utilizing two types of membranes and utilizing pressure ratio as the guidance to design the stages. From these examinations, we concluded that high membrane selectivity is critically needed, while high membrane permeability has limited impact for practical applications. Process design and economics for biogas purification was utilized as an example to demonstrate the need for high selectivity membranes. We further identified some gas separation applications that are critically in need of high membrane selectivities, such as CO2 capture from flue gases, and highlighted recent progress in membrane materials with high gas selectivities for these applications.

Advances in the Use of Nanocomposite Membranes for Carbon Capture Operations

“…e purity of the product and recuperation rate are two key necessities for pragmatic gas separation. Ding [51] concluded that high membrane penetrability has restricted effect for applications in practical scenarios, while the same report highlighted the basic requirement for high membrane selectivity. For gas separation sets, practically all information points are underneath the clear line called "upper limit" in majority of the penetrable gas selectivity and permeability log-log plots (Figure 3).…”

“…For a region with limited membrane selectivity, the process of membrane separation will significantly benefit from a high selectivity, while in the region of limited pressure ratio, the advantage of high membrane selectivity is limited [51].…”

Recent advances in simulating gas permeation through MOF membranes

“…Membrane-based gas separation has environmental and economic advantages due to its renewable and continuous operation, and low energy consumption. 1 2 The membrane selectivity and gas permeability (or permeance) are the key parameters to describe the performance of a membrane. Although the commercial market is currently dominated by polymeric membranes due to their scalability and low cost, 3 they possess a trade-off between selectivity and gas permeability.…”

“…Membrane-based gas separation has environmental and economic advantages due to its renewable and continuous operation, and low energy consumption. 1 Membranes today have several industrially important gas separation applications such as nitrogen separation from air (O 2 /N 2 ), natural gas purification (CO 2 /CH 4 , H 2 S/CH 4 , He/CH 4 ), hydrogen recovery (H 2 /N 2 , H 2 /CH 4 , H 2 /CO), and recovery of light olefins (C 3 H 6 /N 2 , C 2 H 4 /N 2 , C 2 H 4 /Ar, CH 4 /N 2 ). 2 The membrane selectivity and gas permeability (or permeance) are the key parameters to describe the performance of a membrane.…”

Influence of ionic liquid-like cationic pendants composition in cellulose based polyelectrolytes on membrane-based CO2 separation

“…The material and process optimisation yielded selectivities exceeding 100 with moderate permeances of approximately 10 GPU, surpassing the Robeson upper bound for C0 2 /N 2 . While excellent in lab-scale testing, these PE separation parameters can limit the industrial scale CO 2 separation, as higher gas fluxes are still required (Ding, 2020;Karaszova et al, 2020;Lee & Kim, 2020;Merkel, Lin, Wei, & Baker, 2010;Scholes, 2020).…”