PDF Publication Title:
Text from PDF Page: 006
major hurdle, namely the alcohol crossover, while maintaining highly efficient membrane with good proton conductivity. Silva, et.al.66 studied this type of membrane and via simulation reported that increasing the proton conductivity can reduce the Ohmic loss and obtaining a low permeability of methanol crossover. Meanwhile, other researchers investigated the membrane modification to increase its efficiency. Chalkova, et.al. used a Nafion-TiO2 composite membrane to obtain six times higher current density67, while Han, et.al.68 studied the zeolite composite membrane which more stable at high temperature that indirectly affects the permeability. The introduction of AEM at the first place was also in search of solutions of the same problem. Unlike the FC system with PEM at acidic condition, AEM was introduced in an alkaline system. The water was reduced to OH- which travels to the anode which further reacted with the alcohol. The AEM was reported to have a lower ethanol crossover while also improving the water management.65 Zakaria, et.al.65 summarized the materials which commonly used in DAFC membrane, which are the Nafion from Dupont, Sulfonated Poly ether ether ketone (SPEEK), and polyvinyl acetate (PVA). A lot of researchers 69-80 developed composites based on those materials to improve the efficiency of the DAFC. The development occurred in both PEM and AEM. The improvement varies from a higher current density, into better physical stabilities. FIGURE 3. Ilustration of Proton Exchange Membrane in DAFC ZEOLITE IN DIRECT ALCOHOL FUEL CELLS Beside those materials mentioned above, zeolite was also introduced as an alternative material for DAFC membrane. Just like other PEM materials, zeolite has good proton conductivity. Figure 4 shows the transport mechanism in a PEM. The zeolite itself has a similarity to other PEM materials which makes it suitable for a DAFC. The zeolite membrane may appear in the form of pure zeolite itself,68 as a composite with mentioned materials73, 75, 76, 81-83 or as a composite form with other new materials.84 Compared to the existing membrane materials, the zeolite composite membranes give improved performance in term of proton conductivity and alcohol crossover. Zeolites, as a class of crystalline aluminosilicates, have considerable proton conductivity, hygroscopic and stable at high temperature.68, 76, 82 Incorporation of zeolite into existing membranes will block the pores in membrane matrices81 thus increases the diffusion resistance and reduce the alcohol crossover. The alcohol crossover in a zeolite composite membrane is also affected by the hydrophobicity of zeolites.84 This may follow two possible mechanisms. A hydrophobic zeolite will have a low affinity to water giving high permeability to the alcohol while a hydrophilic one works the opposite way.81, 84 Meanwhile, a zeolite may have a different interaction with the base modified materials regarding to its hydrophobicity. The final performance of a zeolite composite membrane may vary depends on the base material and the type of zeolite used in term of hydrophobicity and pore size. Several types of zeolite have been used in form of composite membrane. Mordenite, chabazite and clinoptilotite76 were reported to be able to increase the power density of Nafion PEM and worked at 140°C. Another researcher84 studied various zeolites (3A, 4A, 5A, 13X, modernite and HZSM-5) in chitosan based membrane and found that the membrane performance is highly dependent to the zeolite pore size and hydrophobicity. The hydrophilic zeolites (type A and 13-X) increase the methanol permeability in chitosan composite membranes while the hydrophobic ones (modernite and HZSM-5) give the opposite. Comparison of FC performance using various membranes is shown in Table 1. 020030-5PDF Image | Zeolite modification for direct alcohol fuel cells DAFCs
PDF Search Title:
Zeolite modification for direct alcohol fuel cells DAFCsOriginal File Name Searched:
zeolite-modification-dafc.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 | RSS | AMP |