Metal–Organic Frameworks for Separations

Kenji Sumida, David L. Rogow, Jarad A. Mason, Thomas M. McDonald, Eric D. Bloch, Zoey R. Herm, Tae-Hyun Bae, Jeffrey R. Long

Carbon Dioxide Capture in Metal–Organic Frameworks

Overview of membrane science and technology membrane transport theory membrane and modules concentration polarization reverse osmosis ultrafiltration microfiltration gas separation pervaporation ion exchange membrane processes - electrodialysis carrier facilitated transport medical applications of membranes other membranes processed.

Membrane Technology and Applications

A ceramic fuel cell in an all solid-state energy conversion device that produces electricity by electrochemically combining fuel and oxidant gases across an ionic conducting oxide. Current ceramic fuel cells use an oxygen-ion conductor or a proton conductor as the electrolyte and operate at high temperatures (>600°C). Ceramic fuel cells, commonly referred to as solid-oxide fuel cells (SOFCs), are presently under development for a variety of power generation applications. This paper reviews the science and technology of ceramic fuel cells and discusses the critical issues posed by the development of this type of fuel cell. The emphasis is given to the discussion of component materials (especially, ZrO2 electrolyte, nickel/ZrO2 cermet anode, LaMnO3 cathode, and LaCrO3 interconnect), gas reactions at the electrodes, stack designs, and processing techniques used in the fabrication of required ceramic structures.

Ceramic Fuel Cells

The escalating level of atmospheric carbon dioxide is one of the most pressing environmental concerns of our age. Carbon capture and storage (CCS) from large point sources such as power plants is one option for reducing anthropogenic CO(2) emissions; however, currently the capture alone will increase the energy requirements of a plant by 25-40%. This Review highlights the challenges for capture technologies which have the greatest likelihood of reducing CO(2) emissions to the atmosphere, namely postcombustion (predominantly CO(2)/N(2) separation), precombustion (CO(2)/H(2)) capture, and natural gas sweetening (CO(2)/CH(4)). The key factor which underlies significant advancements lies in improved materials that perform the separations. In this regard, the most recent developments and emerging concepts in CO(2) separations by solvent absorption, chemical and physical adsorption, and membranes, amongst others, will be discussed, with particular attention on progress in the burgeoning field of metal-organic frameworks.

Carbon Dioxide Capture: Prospects for New Materials

Ordered mesoporous silica fibers offer potential industrial application in several areas including polymerization catalysis and separation. Understanding the effects of synthesis conditions on these fibers prepared by the interfacial self-assembly growth method is important to their production and application. The focus of this work is to understand the effect of two previously unstudied factors: silica source height (tetrabutylorthosilicate, TBOS) and the humidity, on the formation of ordered mesoporous silica fibers by the interfacial self-assembly method. Here the TBOS content, interface area, height of source, and humidity of the environment were varied to study their effect on fiber growth. The results show that the TBOS content and interface area do not have a significant impact on results of ordered mesoporous silica fibers. Increasing silica source height or environmental humidity, which lowers the water evaporation rate, gives silica fibers with lower length, less ordered inner pore structure and macroscopic morphology, and smaller pore size. Attempts to mix the growth medium eliminate the fiber morphology and yield gyroidal shapes. A mechanism that combines evaporation of water resulting in local concentration and surfactant, self-assembly, and reaction and diffusion of silica source is proposed to describe the formation of ordered mesoporous silica fibers.

Ordered mesoporous silica fibers: effects of synthesis conditions on fiber morphology and length

Synthesis and Characterization of Ordered Meso-Macro-Porous Silica Membranes on a Porous Alumina Support*

A modified chemical vapour deposition (CVD) and electrochemical vapour deposition (EVD) technique is developed to prepared microporous or dense ceramic membranes by modifying ultrafiltration alumina membranes. Using this CVD/EVD technique, thin (2-5μm) or very thin (0.2-1μm) dense gastight yttria stabilized zirconia films which are oxygen semipermeable were grown on various types of porous substrates. The surface properties and pore size of the top layer of the alumina membranes were modified by depositing a zirconia/yttria solid solution on the internal pore surface of the membrane top layer in order to obtain gas separation properties of surface diffusion or microporous diffusion.

Microporous and dense ceramic membranes prepared by CVD and EVD

https://www.jstage.jst.go.jp/article/membrane/31/3/31_170/_pdf

Inorganic Membranes for Gas Separation and Purification

For the permeation of compressed and supercritical fluids through porous membranes, the investigation on major influence factors and process modeling is essential. The permeance of helium, nitrogen and carbon dioxide at various temperature, pressure and pressure difference was measured at first. A new model equation was developed by modifying the two-term dusty-gas model. The variation of viscosity with pressure, especially in the near-critical region where the possible abnormal change of viscosity with pressure may exist, was considered in the model development. The results of experimental measurement and theoretical analyses show that the permeation of helium in porous membrane agrees well with the two-term dusty-gas model due to its minor change of viscosity with pressure. Whereas, the influence of viscosity change on nitrogen permeation is not negligible in the pressure range of investigation. In the near-critical region, the permeation of carbon dioxide is obviously increased due to its phase transition in membrane pores. However, the modified model is in good agreement with the measured permeance of CO2 at both low-pressure and high-pressure regions.

Y.S. Lin

Papers

Ordered mesoporous silica fibers: effects of synthesis conditions on fiber morphology and length

Synthesis and Characterization of Ordered Meso-Macro-Porous Silica Membranes on a Porous Alumina Support*

Microporous and dense ceramic membranes prepared by CVD and EVD

Inorganic Membranes for Gas Separation and Purification

Permeation of compressed and supercritical fluids through porous membranes