Carbon dioxide facilitated transport

Cadmium(II) transport, over Hg(II) and Zn(II). 102-104 Carbon dioxide facilitated transport, 111 separated from nitrogen in ILMs, 146,150 Carbon monoxide facilitated transport, 112 reversible binding, 30-32 Carboxylate ionophore antibiotics, metal ion transport, 86 Carrier molecule effect on solute flux, 4 function in facilitated transport, 124 Carrier-facilitated transport—... 

Amide-containing dibenzo-16-crown-5 compounds, transport of metal perchlorates, 161-165 Amine(s) as carriers, carbon dioxide facilitated transport through functional membranes prepared by plasma graft polymerization, 252-268 Amine solutions, carbon dioxide facilitated transport through supported liquid membranes, 239-250 Amino acid derivatives, use as heavy metal ion carriers, 175-179... 

Hematopoietic (blood) cells transport oxygen and carbon dioxide, contribute to host immunity, and facilitate blood clotting [1], A complex, interrelated, and multistep process, called hematopoiesis, controls the production as well as the development of specific marrow cells from immature precursor cells to functional mature blood cells. This well-regulated process also allows for replacement of cells lost through daily physiologic activities. The proliferation of precursor cells, the maturation of these into mature cells, and the survival of hematopoietic cells require the presence of specific growth factors. 

Transport. A wellknown transport protein is hemoglobin in the erythrocytes (bottom left). It is responsible for the transport of oxygen and carbon dioxide between the lungs and tissues (see p.282). The blood plasma also contains many other proteins with transport functions. Prealbumin (transthyretin middle), for example, transports the thyroid hormones thyroxin and triiodothyronine. Ion channels and other integral membrane proteins (see p.220) facilitate the transport of ions and metabolites across biological membranes. 

Figure 11.20 Flow schematics of (a) a steam sweep configuration used in the facilitated transport of carbon dioxide [25,26] and (b) a liquid hexane sweep used in the transport of propylene [27]...

From the late 1960s to the early 1980s, Ward and others at General Electric studied facilitated transport membranes, particularly for separation of the acid gases carbon dioxide and hydrogen sulfide from methane and hydrogen [23-26],... 

Figure 11.23 Facilitated transport of carbon dioxide through an immobilized carbonate/bicarbonate solution [25]. Reprinted with permission from S.G. Kimura, S.L. Matson and W.J. Ward HI, Industrial Applications of Facilitated Transport, in Recent Developments in Separation Science, N.N. Li, J.S. Dranoff, J.S. Schultz and P. Somasundaran (eds) (1979). Copyright CRC Press, Boca Raton, FL...

Concurrently with the work on carbon dioxide and hydrogen sulfide at General Electric, Steigelmann and Hughes [27] and others at Standard Oil were developing facilitated transport membranes for olefin separations. The principal target was the separation of ethylene/ethane and propylene/propane mixtures. Both separations are performed on a massive scale by distillation, but the relative volatilities of the olefins and paraffins are so small that large columns with up to 200 trays are required. In the facilitated transport process, concentrated aqueous silver salt solutions, held in microporous cellulose acetate flat sheets or hollow fibers, were used as the carrier. 

W.J. Ward III and W.L. Robb, Carbon Dioxide-Oxygen Separation Facilitated Transport of Carbon Dioxide Across a Liquid Film, Science 156, 1481 (1967). 

Ward, W.J.I. and Robb, W.L. (1967) Carbon dioxide-oxygen separation Facilitated transport of carbon dioxide across a liquid film. Science, 156, 1481. 

Quinn R, Appleby JB, and Fez GP. New facilitated transport membraness for the separation of carbon dioxide from hydrogen and methane. J. Membr. Sci. 1995 104 139-146. 

FIGURE 13.14 Schematic diagrams of facilitated transport of gas using capillary membrane module for removal and enrichment of carbon dioxide, (a) Experimental capillary membrane apparatus and (b) capillary membrane modules with permeation of carrier solution. (From Teramoto, M., Ohnishi, N., Takeuchi, N., et al., Sep. Purif TechnoL, 30, 215, 2003. With permission.)... 

One of the first applications of TSOSs was reported in 2002. Davis and his team have shown that an amine-derived imidazolium salt can capture carbon dioxide by forming a ammonium carbamate [28], Primary amine functionalized imidazolium salts have also been used for facilitating C02 transport through a supported liquid membrane showing high selectivity and high stability for CH4/C02 separation [50] (Fig. 18). 

Enzymes are proteins that act as catalysts for specific biochemical reactions in living systems. The reactants in enz)une-catalyzed reactions are called substrates. Thousands of vital processes in our bodies are catalyzed by many distinct enzymes. For instance, the enzyme carbonic anhydrase catalyzes the combination of CO2 and water (the substrates), facilitating most of the transport of carbon dioxide in the blood. This combination reaction, ordinarily uselessly slow, proceeds rapidly in the presence of carbonic anhydrase a single molecule of this enzyme can promote the conversion of more than 1 million molecules of carbon dioxide each second. Each enzyme is extremely specific, catalyzing only a few closely related reactions—or, in many cases, only one particular reaction—for only certain substrates. Modern theories of enzyme action attribute this to the requirement of very specific matching of shapes (molecular geometries) for a particular substrate to bind to a particular enzyme (Figure 16-19). 

The addition of ethanol to gasoline reduces harmful vehicle emissions and facilitates the reduction or removal of toxic air components, which are commonly found additives in gasoline. Emissions of carbon dioxide (CO2), the primary greenhouse gas contributing to global warming, have increased steadily, and the transportation sector alone accounts for 33% of total emissions. It is estimated that an 85% ethanol fuel would reduce greenhouse gas emissions between 15%i and Ethanol-blended fuels would reduce... 

Gallagher, P. M. Athayde, A. L. Ivory, C. F. "The Combined Flux Technique for Diffusion-Related Problems in Partial Equilibrium Application to the Facilitated Transport of Carbon Dioxide in Aqueous Bicarbonate Solutions" Chem. Eng. Sci., 1986b, 41(3), p. 567. 

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