Ni–BaCe0.95Tb0.05O3−δ cermet membranes for hydrogen permeation

Perovskite Membranes: Advancements and Challenges in Gas Separation, Production, and Capture

Perovskite membranes have gained considerable attention in gas separation and production due to their unique properties such as high selectivity and permeability towards various gases. These membranes are composed of perovskite oxides, which have a crystalline structure that can be tailored to enhance gas separation performance. In oxygen enrichment, perovskite membranes are employed to separate oxygen from air, which is then utilized in a variety of applications such as combustion and medical devices. Moreover, perovskite membranes are investigated for carbon capture applications to reduce greenhouse gas emissions. Further, perovskite membranes are employed in hydrogen production, where they aid in the separation of hydrogen from other gases such as methane and carbon dioxide. This process is essential in the production of clean hydrogen fuel for various applications such as fuel cells and transportation. This paper provides a review on the utilization and role of perovskite membranes in various gas applications, including oxygen enrichment, carbon capture, and hydrogen production.

Dual-Phase Mixed Protonic-Electronic Conducting Hydrogen Separation Membranes: A Review

Owing to the excellent properties of high selectivity, high thermal stability, and low cost, in the past twenty years, mixed protonic-electronic conducting hydrogen separation membranes have received extensive attention. In particular, dual-phase mixed protonic-electronic conducting membranes with high ambipolar conductivity are more attractive because of the high hydrogen permeability. This paper aimed to present a review of research activities on the dual-phase membranes, in which the components, the characteristics, and the performances of different dual-phase membranes are introduced. The key issues that affect the membrane performance such as the elimination of the inter-phase reaction, the combination mode of the phases, the phase ratio, and the membrane configuration were discussed. The current problems and future trends were simply recommended.

Proton conducting membranes for hydrogen and ammonia production

Dense proton conducting membranes possess 100% hydrogen selectivity and excellent stability under practical conditions, and serve as promising technologies for hydrogen and ammonia production.

The opportunity of membrane technology for hydrogen purification in the power to hydrogen (P2H) roadmap: a review

The global energy market is in a transition towards low carbon fuel systems to ensure the sustainable development of our society and economy. This can be achieved by converting the surplus renewable energy into hydrogen gas. The injection of hydrogen (⩽10% v/v) in the existing natural gas pipelines is demonstrated to have negligible effects on the pipelines and is a promising solution for hydrogen transportation and storage if the end-user purification technologies for hydrogen recovery from hydrogen enriched natural gas (HENG) are in place. In this review, promising membrane technologies for hydrogen separation is revisited and presented. Dense metallic membranes are highlighted with the ability of producing 99.9999999% (v/v) purity hydrogen product. However, high operating temperature (⩾300 °C) incurs high energy penalty, thus, limits its application to hydrogen purification in the power to hydrogen roadmap. Polymeric membranes are a promising candidate for hydrogen separation with its commercial readiness. However, further investigation in the enhancement of H₂/CH₄ selectivity is crucial to improve the separation performance. The potential impacts of impurities in HENG on membrane performance are also discussed. The research and development outlook are presented, highlighting the essence of upscaling the membrane separation processes and the integration of membrane technology with pressure swing adsorption technology.

Catalytic mixed conducting ceramic membrane reactors for methane conversion

Schematic of catalytic mixed conducting ceramic membrane reactors for various reactions: (a) O₂ permeable ceramic membrane reactor; (b) H₂ permeable ceramic membrane reactor; (c) CO₂ permeable ceramic membrane reactor.

Asymmetric nickel hollow fibres as the catalytic membrane reactor for CO2 hydrogenation into syngas

Herein, we report the development of highly asymmetric Ni hollow fibres with a dense skin layer integrated on a porous substrate by a single-step spinning and sintering technique.

Recent Advances in Pd-Based Membranes for Membrane Reactors

Palladium-based membranes for hydrogen separation have been studied by several research groups during the last 40 years. Much effort has been dedicated to improving the hydrogen flux of these membranes employing different alloys, supports, deposition/production techniques, etc. High flux and cheap membranes, yet stable at different operating conditions are required for their exploitation at industrial scale. The integration of membranes in multifunctional reactors (membrane reactors) poses additional demands on the membranes as interactions at different levels between the catalyst and the membrane surface can occur. Particularly, when employing the membranes in fluidized bed reactors, the selective layer should be resistant to or protected against erosion. In this review we will also describe a novel kind of membranes, the pore-filled type membranes prepared by Pacheco Tanaka and coworkers that represent a possible solution to integrate thin selective membranes into membrane reactors while protecting the selective layer. This work is focused on recent advances on metallic supports, materials used as an intermetallic diffusion layer when metallic supports are used and the most recent advances on Pd-based composite membranes. Particular attention is paid to improvements on sulfur resistance of Pd based membranes, resistance to hydrogen embrittlement and stability at high temperature.

Hydrogen separation through tailored dual phase membranes with nominal composition BaCe0.8Eu0.2O3-δ:Ce0.8Y0.2O2-δ at intermediate temperatures

Hydrogen permeation membranes are a key element in improving the energy conversion efficiency and decreasing the greenhouse gas emissions from energy generation. The scientific community faces the challenge of identifying and optimizing stable and effective ceramic materials for H₂ separation membranes at elevated temperature (400-800 °C) for industrial separations and intensified catalytic reactors. As such, composite materials with nominal composition BaCe_0.8Eu_0.2O_3-δ:Ce_0.8Y_0.2O_2-δ revealed unprecedented H₂ permeation levels of 0.4 to 0.61 mL·min^-1·cm^-2 at 700 °C measured on 500 μm-thick-specimen. A detailed structural and phase study revealed single phase perovskite and fluorite starting materials synthesized via the conventional ceramic route. Strong tendency of Eu to migrate from the perovskite to the fluorite phase was observed at sintering temperature, leading to significant Eu depletion of the proton conducing BaCe_0.8Eu_0.2O_3-δ phase. Composite microstructure was examined prior and after a variety of functional tests, including electrical conductivity, H₂-permeation and stability in CO₂ containing atmospheres at elevated temperatures, revealing stable material without morphological and structural changes, with segregation-free interfaces and no further diffusive effects between the constituting phases. In this context, dual phase material based on BaCe_0.8Eu_0.2O_3-δ:Ce_0.8Y_0.2O_2-δ represents a very promising candidate for H₂ separating membrane in energy- and environmentally-related applications.

SrCe0.95Y0.05O3−δ–ZnO dual-phase membranes for hydrogen permeation

A hydrogen permeation membrane plays a key role in membrane reactor applications for hydrogen production.

Enhanced stability of Zr-doped Ba(CeTb)O3−δ-Ni cermet membrane for hydrogen separation

The Ni-BCTZ membrane can be steadily operated under both dry and humid conditions for hydrogen separation, which shows an extremely enhanced stability compared with Ni-BCT due to Zr-doping.