Background Information on Hydrogen

This appendix provides general background information on hydrogen—what it is, how it is produced, and what its current and potential applications are. This appendix also describes some technological hurdles to the use of hydrogen as an energy source. 

Four appendixes are included. Appendix A contains standard materials selection used by many refiners and contractors in petroleum processing equipment. Appendix B contains a rules of thumb overview of refinery materials of construction. Appendix C contains background information on hydrogen diffusion through vessel walls, and Appendix D contains a standard specification for steel line pipe. 

However, the discussion on social impacts cannot only be limited on the propulsion system but must also include the production, transport, delivery and storage of hydrogen. (For more background information on the discussion of energy production and environmental impacts, see EEA, 2006b EPA, 2007 IAEA, 2007.) Important new impacts of hydrogen based on hydrogen production include ... 

This background information on mass transport and gas solubility can be made more relevant by discussion of some examples. A question about mass transfer already has been raised by Blackmond and co-workers with regard to the study of Landis and Halpem on the hydrogenation of methyl-Z-a-acetamidocinnamate by RhCdipamp) in methanol with a magnetically stirred reactor. This issue has been mentioned in Chapter 5. A preliminary analysis would suggest that mass transport should not have been a problem... 

If the isotope has no spin, then < b > = < b as < b> = b and there is no incoherent scattering for neutrons. Only coherent scattering contains information on the stmcture of the sample. The incoherent cross section contains no information on interference effects and forms an isotropic (flat) background which must be subtracted off in SANS stmctural investigations. While most of the atoms encountered in neutron scattering from polymers are mainly coherent scatterers (e.g., carbon, oxygen, deuterium), there is one important exception [8,22,23]. In the case of hydrogen (H )... 

The mechanistic background for such a comparison is illustrated in Figure 10 which represents in more detail the pathway of hydroisomerization and hydrocracking of two n-alkanes. Branched carbenium ions are formed via n-alkenes and linear carbenium ions. Then, either desorption or -scission may occur in parallel reactions. Desorption (followed by hydrogenation) of a given carbenium ion yields an iso-alkane with the same carbon skeleton. /S - scission, on the other hand, yields fragments of definite carbon numbers ( /3 -scissions which would yield or are excluded). Thus a comparison between relative concentrations of the iso-alkanes and relative probabilities of the cracking reactions may be informative since both sets of data are determinable independently from each other. 

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