PVA/nanocellulose nanocomposite membranes for CO2 separation from flue gas

Abstract

In this paper, we explore the use of nanocelluloses as an additive to poly (vinyl alcohol) (PVA) nanocomposite membranes for CO 2 /N 2 mixed-gas separation. Our findings are that several types of nanocellulose can be used to improve membrane performance. PVA/cellulose nanocrystals (CNC) nanocomposite membranes have the most promising performance, with increased CO 2 permeance (127.8 ± 5.5 GPU) and increased CO 2 /N 2 separation factor (39 ± 0.4) compared to PVA composite membranes, with permeance 105.5 ± 1.9 GPU and separation factor 36 ± 0.5. The performance of PVA/CNC membranes is similar compared to PVA/carbon nanotubes (CNTs) membranes shown earlier. Thus, CNTs can be replaced by CNC that is biodegradable and non-toxic. Investigating several different nanocellulose types reveal that a high nanocellulose charge and small nano-cellulose particles are important nanocellulose traits that improve membrane performance.

Swelling Resistance and Mechanical Performance of Physical Crosslink‐Based Poly(Vinyl Alcohol) Hydrogel Film with Various Molecular Weight

“…Polyvinyl alcohol (PVA) is a biodegradable and environmentally friendly polymer material with good water solubility and membrane forming properties. Recently, PVA hydrogels with a three‐dimensional network built by crosslinked chain networks (physical or chemical one) have received much attention on its excellent biocompatibility and feasibility in many biomedical applications, such as agricultural application, biomedical applications, food packaging, separation and purification, catalytic chemistry, electrochemistry, adsorption chemistry, and so on. These numerous applications can be based on the specific hydrogen bonding between inter and intramolecular hydrogen bonds in PVA chains, whose strength has an influence of structure and mechanical properties of PVA gel .…”

A Brief Review of Nanocellulose Based Hybrid Membranes for CO2 Separation

“…The advantages of CNC include uniform size with nanometric dimensions in both length and width. In certain applications such as high pressure gas separations, CNF with a higher aspect ratio and tensile strength might be desirable [82]. As mentioned in Section 1.2, CNF is often produced in a two-step process starting with a chemical/ enzymatic pre-treatment step followed by a mechanical step.…”

“…As mentioned in Section 1.2, CNF is often produced in a two-step process starting with a chemical/ enzymatic pre-treatment step followed by a mechanical step. In addition to improve the processability as well as making the size distribution more uniform, the pre-treatment step can contribute to nanocelluloses with different properties tailored different gas separation applications (e.g., introduction of CO 2 reactive groups) [82].…”

“…Torstensen et al synthesized several different types of nanocellulose and used them for CO 2 capture from flue gas [82]. Three different in-house CNF's are compared to commercially CNC and the main focus of the publication was investigating which properties of nanocellulose are important for gas separation membranes.…”

“…However, when mixed with polymers based on solution-diffusion mechanism, the presence of nanocellulose does not resulted in a significant change in selectivity (e.g., PVA [62]). Conversely, adding different nanocellulose into non-facilitated transport polymeric matrix normally resulted in a high CO 2 permeability/permeance, while the selectivity of CO 2 over other gases are almost unchanged [62,82].…”