PDF Publication Title:
Text from PDF Page: 051
Energies 2020, 13, 420 51 of 96 Furthermore, leak detection is challenging for hydrogen. Indeed, the flame is invisible, and odorants such as mercaptans that are typically used for natural gas odorization are not suitable for hydrogen as well as many gas sensors and analyzers [640]. The gas sensor that is generally employed by transmission system operators (TSOs) is the flame ionization detector (FID). The FID is designed for the detection of hydrocarbons but is not sensitive to hydrogen compounds [641,642]. Further, gas chromatography with a thermal conductivity detector and helium as a gas carrier are inadequate for hydrogen detection since their thermal conductivity is comparable and the response is non-linear. Therefore, argon or nitrogen gas carriers or alternative gas sensors have to be adopted [643]. New sensors are studied and developed to detect blends of hydrogen and natural gas. For example, detectors based on electrochemical cells [644], semiconductors [645], the combination of calorimeter and thermoelectric gas sensors [646] and selective membranes [647] are proposed. In conclusion, it is possible to establish that an admixture of hydrogen and natural gas with a hydrogen concentration up to 10% by volume can generally be injected into the natural gas grid with no significant problems of safety and efficiency [648,649]. 5.2. Gas Network Injection Synthetic natural gas grid injection does not involve specific issues apart from respecting the gas quality requirements. Therefore, synthetic natural gas upgrading is commonly necessary. Indeed, especially water and carbon dioxide have to be removed to match gas network specifications, and LPG has to be added to tune the heating value [650]. Instead, hydrogen injection into the gas network presents several critical issues. The natural gas network cannot be used for pure hydrogen transport without modification of network components since the physical and chemical properties of hydrogen and natural gas are different. Anyhow, in the current natural gas grid could be injected a blend of natural gas and hydrogen. The maximum concentration admissible depends on pipeline material, operating pressure and national legislation. The upper limit established according to pipeline resistance is in the range of 20%–30% [2]. However, the maximum hydrogen content by volume accepted in the natural gas transmission system ranges in the United States between 5% and 15%, and in Europe between 0.1% and 12% [640]. Hydrogen injection into the natural gas grid can impact on transport capacity and pipeline properties. The natural gas energy density is more than three times higher than that of hydrogen. The higher heating value is approximately 13 MJ/Nm3 for hydrogen and 40 MJ/Nm3 for natural gas. Therefore, a higher amount of hydrogen is needed to satisfy the same energy requirement [651]. However, this reduces the pipeline transport capacity since the maximum allowed pressure is imposed by safety constraints [652]. The linepack capacity is also reduced. Linepack is an essential aspect of the gas transmission network that consists of short-term storage into the pipeline of a volume of gas for peak demands coverage. The linepack capacity for hydrogen is approximately 65%–70% of natural gas linepack on a volume basis and nearly four times less on energy base [653]. Moreover, pipelines mechanical properties are affected by hydrogen embrittlement. The hydrogen diffuses easily through the pipeline material due to the low molecular radius and combines in submicroscopic voids of the carbon steel, leading to trapped molecules and subsurface fissuring [654]. The hydrogen embrittlement of steel facilitates the degradation of mechanical properties (fracture toughness, crack propagation and fatigue resistance and ductility) and promotes the crack growth in pipeline walls [655]. Indeed, the hydrogen diffusion through dislocation and accumulation in the metal lattice leads to an increase in internal pressure and crack initiation and propagation [656]. The metal embrittlement is enhanced by high hydrogen concentration, high operating pressure and temperature, cyclic loads and low steel resistance [657]. Therefore, the embrittlement depends on the composition of pipeline material as well as the pressure fluctuation. The higher the pressure fluctuation, the higher the hydrogen embrittlement and the material fatigue [658].PDF Image | Green Synthetic Fuels
PDF Search Title:
Green Synthetic FuelsOriginal File Name Searched:
energies-13-00420.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)