An official website of the United States government
Abstract Polymers are unarguably the most broadly used membrane materials for molecular separations and beyond. Motivated by the commercial success of membrane‐based desalination and permanent gas separations, glassy polymer membranes are increasingly being studied for hydrocarbon separations. They represent a class of challenging yet economically impactful bulk separations extensively practiced in the refining and petrochemical industry. This review discusses recent developments in membrane‐based hydrocarbon separations using glassy polymer membranes relying on the sorption‐diffusion mechanism. Hydrocarbon separations by both diffusion‐selective and sorption‐selective glassy polymer membranes are considered. Opinions on the likelihoods of large‐scale implementation are provided for selected hydrocarbon pairs. Finally, a discussion of the challenges and outlook of glassy polymer membrane‐based hydrocarbon separations is presented.
more »
« less
Fluorine-rich poly(arylene amine) membranes for the separation of liquid aliphatic compounds
We explored the potential for membrane materials to reduce energy and carbon requirements for the separation of aliphatic hydrocarbon feedstocks and products. We developed a series of fluorine-rich poly(arylene amine) polymer membranes that feature rigid polymer backbones with segregated perfluoroalkyl side chains. This combination imbues the polymers with resistance to dilation induced by hydrocarbon immersion without the loss of solution-based membrane fabrication techniques. These materials exhibit good separation of liquid-phase alkane isomers at ambient temperatures. The integration of these polymeric membranes into fuel and chemical feedstock separation processes was investigated in a series of experiments. Technoeconomic analyses based on these experiments indicate that the best-performing membrane materials can substantially reduce the energy costs and associated carbon emissions of hydrocarbon separations (two to 10 times, depending on product specifications).
more »
« less
- Award ID(s):
- 1921873
- PAR ID:
- 10653321
- Publisher / Repository:
- AAAS
- Date Published:
- Journal Name:
- Science
- Volume:
- 387
- Issue:
- 6730
- ISSN:
- 0036-8075
- Page Range / eLocation ID:
- 208 to 214
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
This study addresses the challenge of generalizable fabrication of metal‐organic framework (particularly zeolitic imidazolate frameworks (ZIF)) hollow fiber membranes that can allow a broader range of separations including hydrocarbon (“petrochemical”) as well as organics/water (“biorefining”) separations. We report a novel strategy that combines fluidic membrane processing with chemically inert carbon hollow fibers to produce robust ZIF membranes. Macroporous carbon hollow fibers are successfully fabricated by pyrolytic conversion of cross‐linked polymer hollow fibers. This step allows the use of a wide range of relatively aggressive fluidic processing solvents and conditions. Using these inert fiber supports, the fabrication of ZIF‐90 membranes is demonstrated and their butane isomer separations are investigated for the first time. Furthermore, ZIF membranes on carbon hollow fibers can be used in the separation of water/organic mixtures without the issue of fiber swelling or dissolution as seen in ZIF/polymer hollow fiber membranes. ZIF‐8/carbon membranes show stable operation spanning several days for dehydration of furfural and ethanol, with high water permeances and separation factors. In all cases, the ZIF membranes are prepared without any seeding, support modification, or postsynthesis procedures, thereby simplifying the fabrication process and increasing the potential for larger‐scale membrane fabrication.more » « less
-
Polymeric membranes have become essential for energy-efficient gas separations such as natural gas sweetening, hydrogen separation, and carbon dioxide capture. Polymeric membranes face challenges like permeability-selectivity tradeoffs, plasticization, and physical aging, limiting their broader applicability. Machine learning (ML) techniques are increasingly used to address these challenges. This review covers current ML applications in polymeric gas separation membrane design, focusing on three key components: polymer data, representation methods, and ML algorithms. Exploring diverse polymer datasets related to gas separation, encompassing experimental, computational, and synthetic data, forms the foundation of ML applications. Various polymer representation methods are discussed, ranging from traditional descriptors and fingerprints to deep learning-based embeddings. Furthermore, we examine diverse ML algorithms applied to gas separation polymers. It provides insights into fundamental concepts such as supervised and unsupervised learning, emphasizing their applications in the context of polymer membranes. The review also extends to advanced ML techniques, including data-centric and model-centric methods, aimed at addressing challenges unique to polymer membranes, focusing on accurate screening and inverse design.more » « less
-
Membrane technology has become a promising solution for a wide range of separation processes, including wastewater treatment, solvent recovery, and oil–water separation, due to its low energy consumption, cost-effectiveness, and minimal space needs. However, membrane damage caused by suspended pollutants or improper handling remains a challenge, often leading to decreased filtration capability and the need for replacement of membrane modules. Self-repairing membranes have emerged as a new solution, with various materials demonstrating autonomous healing properties through dynamic bonds such as hydrogen bonds or boronic ester bonds. However, many of these self-repairing membranes suffer from excessive swelling in water, compromising their mechanical stability. Herein, we report a self-repairing and low-swelling polymer network based on dopamine acrylamide (DA) and n-butyl acrylate (BA), crosslinked with p-phenylenediboronic acid (PDBA). The boronic ester bond formation between catechol and boronic acid groups confers self-healing properties to the polymer, while the hydrophobic nature of BA minimizes swelling in water. The polymer exhibits a low swelling ratio of 2.1% after 7 days of submersion in water. A cellulose-based filter paper coated with the polymer demonstrated that it can recover its water flux up to 91% after repairing damage. Lastly, an ultrafiltration polyethersulfone (PES)-based filter coated with the polymer demonstrated that it recovers its solute rejection capability after repairing damage.more » « less
-
The implementation of synthetic polymer membranes in gas separations, ranging from natural gas sweetening, hydrogen separation, helium recovery, carbon capture, oxygen/nitrogen enrichment, etc. , has stimulated the vigorous development of high-performance membrane materials. However, size-sieving types of synthetic polymer membranes are frequently subject to a trade-off between permeability and selectivity, primarily due to the lack of ability to boost fractional free volume while simultaneously controlling the micropore size distribution. Herein, we review recent research progress on microporosity manipulation in high-free-volume polymeric gas separation membranes and their gas separation performance, with an emphasis on membranes with hourglass-shaped or bimodally distributed microcavities. State-of-the-art strategies to construct tailorable and hierarchically microporous structures, microporosity characterization, and microcavity architecture that govern gas separation performance are systematically summarized.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1126/science.adp2619
