PDF Publication Title:
Text from PDF Page: 016
130 TAYLOR CARBONELL DESIMONE 3.2 Metal Extractions The interest in using CO2 for metal extractions has been to capitalize on enhanced diffusivity (mass transfer) and pressure tunability—characteristics that should allow for facile separations (16). The polymer-ligand-metal complexes that form can be readily precipitated from solution by altering the CO2 pressure. Most of the work in CO2 metal extractions has employed common extracting ligands, such as β-diketones, dithiocarbamates, and organophosphorus reagents (25a–h, 26–28). When fluorine-containing moieties are incorporated into the chelating ligands, the metal complexes show enhanced solubility in CO2 (25c,e,g; 27; 28g; 29). Yazdi and Beckman attached CO2-philic oligomer or polymer moieties—consisting of either highly fluorinated or polysiloxane groups—to ligands, improving both the solubility of the metal-ligand complex as well as the ligand extraction efficiency (30a–d). For example, perfluoropolyether-based extractants with dithiocarbamate, dithiol, and picolylamine head groups require only 1.5 eq of chelate for efficient CO2-extractions of mercury (57%–87%), lead (20%–75%), and arsenic (31%– 58%) in CO2 at 2000 psi and room temperature. Powell et al have taken a different approach to incorporate multiple ligand sites onto the backbone of a single CO2- soluble fluorinated acrylate polymer chain, allowing for up to 30 wt % polymer in CO2 (31) (see Figure 8, see color insert). Preliminary extraction efficiencies of 59% were obtained using ligand to metal ratios of 2.7 to 1. CO2-Swellable Supports Environmentally benign cleaning and extraction processes are in high demand, with the search focusing on a solvent and detergents capable of removing a broad range of contaminants from solid and liquid substrates. A combination of physico- chemical processes contributes to the overall contaminant removal rate, including adsorption and penetration of surfactants into the contaminant film, reduction in viscosity as a result of solvent penetration, shear, and secondary solubilization and diffusion into the bulk phase. The development of novel surfactants for CO2 has greatly increased the interest in this solvent for cleaning and extraction processes (52). Cross-linked fluoropolymer beads of 30 μm to 2 mm can be obtained during the controlled agitation of a well-designed suspension polymerization. Crette ́ & DeSimone have prepared beads of this type that swell more than 200% in CO2 (S Crette ́ & JMD DeSimone, unpublished results). Several potential applications for these beads exist, including separation of gas mixtures containing CO2. More specifically, CO2/methane separations can be performed through a high-pressure column filled with fluorinated beads. The gas mixture will be impoverished in carbon dioxide, which will plasticize the fluorinated part of the beads (Figure 13, see color insert). Transition metal and enzymatic catalysis are two other fields of application. Fluorinated copolymers are designed and synthesized either with ligand sites for metal coordination or enzyme attachment sites. 3.3PDF Image | OPPORTUNITIES FOR POLLUTION PREVENTION
PDF Search Title:
OPPORTUNITIES FOR POLLUTION PREVENTIONOriginal File Name Searched:
Ann._Review_Ener.Environ.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)