PDF Publication Title:
Text from PDF Page: 065
(mixture of CO and H2) to aliphatic hydrocarbons. Typical mixtures of linear, branched and oxygenated hydrocarbons, linear paraffins and α-olefins are the main products [273]. As fuel, they are appropriate only as diesel, while for the use as synthetic gasoline, they must be further hydrocracked and isomerized to branched, light hydrocarbons. In industrial term, the direct production of i-paraffins from syngas is of great interest. Physical mixture of Fischer-Tropsch catalyst and zeolite catalyst providing active site for the two reactions was proposed in the literature for the direct synthesis of i-paraffins rich hydrocarbons [274–277]. The Fischer-Tropsch catalyst offers thereby the active sites for the conversion of syngas to linear hydrocarbons which then undergo hydrocracking and isomerization to the desired branched hydrocarbons on the acidic sites of zeolites. Even so, a major problem by applying catalyst mixtures is the random distribution of the active sites. The linear hydrocarbons formed on the active sites of the Fischer-Tropsch catalyst can leave the reaction zone without reaching the active sites of the zeolite for further reforming resulting in low selectivity. In order to improve the migration of the linear hydrocarbons to the active sites of the zeolite, catalysts with core-shell structure have been proposed as a more efficient alternative and extensively studied by the working group of Tsubaki. Accordingly, the selectivity could be significantly improved since the intermediate products are enforced to pass a zeolite membrane in order to desorb from the Fischer-Tropsch catalyst experiencing a higher possibility for further conversion so as to yield the desired product. In detail, the working group of Tsubaki [234,253,254] coated H-ZSM-5 membranes on preshaped Co/SiO2 pellets and evaluated their performances in i-paraffins synthesis from syngas. Thereby, syngas permeated through the membrane to the core catalyst and reacted to straight-chain hydrocarbons which were then hydrocracked and isomerized while passing the zeolite channels as show schematically in Figure 12. The formation of C10+ hydrocarbons was completely suppressed. Moreover, an indication was given that the size of the pellets affects the properties of the capsule catalyst since coating smaller pellets of Co/SiO2 resulted in a higher i-paraffin/n-paraffin ratio. However, the prepared core-shell catalysts showed higher methane selectivity compared to the mechanical mixture of Co/SiO2 and H-ZSM-5 due to the lower diffusion efficiency for CO caused by the different diffusion rates of CO and H2 in the zeolite pores. The same working group managed to coat H-beta membranes onto the surface of Co/Al2O3 pellets and observed excellent performance for the direct synthesis of i-paraffins [239]. Not only the formation of C12+ hydrocarbons was completely suppressed, but also lower methane selectivity was recorded due to the hydrophilicity provided by the zeolite coating. The presence of water favors higher CO concentrations passing the membrane leading to decreased H2/CO ratios in the catalyst core and thus to lower CH4 selectivity. 50PDF Image | Zeolite Catalysis
PDF Search Title:
Zeolite CatalysisOriginal File Name Searched:
Zeolite_Catalysis.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)