Catalytic ceramic oxygen ionic conducting membrane reactors for ethylene production

ABSTRACTMethane conversion to synthesis gas in membrane reactors that use dense mixed electronic-ionic conducting membranes for oxygen separation has received much recent attention. The oxygen flux achievable in these reactors depends on a combination of the bulk diffusion rate for oxygen transport and the surface reaction rate for oxygen activation and either recombination or reaction with methane. Here we compare recent oxygen permeation data for tubular membranes of La0.5Sr0.5Fe0.8Ga0.2O3-δ with our previous results for SrCO0.8Fe0.2O3-δ, SrFeCO0.5O3.25-δ. The pressure dependence of the oxygen permeation flux has been measured at different temperatures and used to determine the relative importance of bulk and surface kinetics for these oxides.

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Indo-U.S. collaborative studies on biocatalytic generation of novel molecular architectures

Pure and Applied Chemistry ◽

10.1351/pac200577010201 ◽

2005 ◽

Vol 77 (1) ◽

pp. 201-208 ◽

Cited By ~ 10

Author(s):

Arthur C. Watterson ◽

Virinder S. Parmar ◽

Rajesh Kumar ◽

Sunil K. Sharma ◽

Najam A. Shakil ◽

...

Keyword(s):

Drug Delivery ◽

Flame Retardant ◽

Chemical Reactions ◽

Value Added ◽

Polymeric Materials ◽

Enzymatic Polymerization ◽

Molecular Architecture ◽

Collaborative Studies ◽

Molecular Architectures

Biocatalytic polymerization reactions on a variety of substrates leading to value-added polymers have been summarized. The main focus of this review is on the control of molecular architecture during enzymatic polymerization reactions. Combined with chemical reactions, several extremely flexible chemo-enzymatic synthetic procedures are described to produce families of new polymeric materials with novel properties. The properties of the synthesized polymers and their applications in various fields, such as drug delivery and flame retardant materials, have also been studied and discussed.

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Electrochemical CO2 conversion into High Value Added Chemicals Using Solid Oxide Proton Conducting Membrane Reactors

ECS Meeting Abstracts ◽

10.1149/ma2019-02/40/1877 ◽

2019 ◽

Keyword(s):

Value Added ◽

Solid Oxide ◽

Membrane Reactors ◽

Co2 Conversion ◽

Proton Conducting ◽

Proton Conducting Membrane

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Valorization of crude glycerol from biodiesel production

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq160303019k ◽

2016 ◽

Vol 22 (4) ◽

pp. 461-489 ◽

Cited By ~ 14

Author(s):

Sandra Konstantinovic ◽

Bojana Danilovic ◽

Jovan Ciric ◽

Slavica Ilic ◽

Dragisa Savic ◽

...

Keyword(s):

Chemical Reactions ◽

Crude Glycerol ◽

Animal Feed ◽

Value Added ◽

Alternative Fuel ◽

Raw Material ◽

Biodiesel Production ◽

Green Solvent ◽

Effective Utilization ◽

Simultaneous Growth

The increased production of biodiesel as an alternative fuel involves the simultaneous growth in production of crude glycerol as its main by-product. Therefore, the feasibility and sustainability of biodiesel production requires the effective utilization of crude glycerol. This review describes various uses of crude glycerol as a potential green solvent for chemical reactions, a starting raw material for chemical and biochemical conversions into value-added chemicals, a substrate or co-substrate in microbial fermentations for synthesis of valuable chemicals and production of biogas and biohydrogen as well as a feedstuff for animal feed. A special attention is paid to various uses of crude glycerol in biodiesel production.

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Surface reactions observed by photoemission electron microscopy (PEEM)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121831 ◽

1992 ◽

Vol 50 (1) ◽

pp. 286-287

Author(s):

H.H. Rotermund

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Work Function ◽

Chemical Reactions ◽

Reaction Diffusion ◽

Dynamic Processes ◽

Clean Surface ◽

Crystal Surfaces ◽

Single Crystal Surfaces ◽

Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

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Microwaves: Application in Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158248 ◽

1990 ◽

Vol 48 (3) ◽

pp. 140-141

Author(s):

Anthony S-Y Leong ◽

David W Gove

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Chemical Reactions ◽

Electromagnetic Waves ◽

Tissue Fixation ◽

Primary Method ◽

Dipolar Molecules ◽

Wide Range ◽

Time Required ◽

Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

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Fine structure and properties of defects in naturally occurring silicates and oxides

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100175430 ◽

1990 ◽

Vol 48 (4) ◽

pp. 460-461

Author(s):

David R. Veblen

Keyword(s):

Chemical Reactions ◽

High Resolution Electron Microscopy ◽

Extended Defects ◽

Single Chain ◽

Naturally Occurring ◽

Resolution Electron ◽

Fine Structures ◽

Image Simulations ◽

Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

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