HR: 13:55h
AN: A23E-02    [Abstracts]
TI: Assessing Leaks in a Global Hydrogen Infrastructure: Can it Perturb the Natural Hydrogen Cycle?
AU: * Padro, C G
EM: padro@lanl.gov
AF: Los Alamos National Laboratory, MS D429, LANL, Los Alamos, NM 87545 United States
AU: Dubey, M K
EM: dubey@lanl.gov
AF: Los Alamos National Laboratory, MS D429, LANL, Los Alamos, NM 87545 United States
AU: Rahn, T A
EM: trahn@lanl.gov
AF: Los Alamos National Laboratory, MS D429, LANL, Los Alamos, NM 87545 United States
AB: The potential of hydrogen leaks from implementation of a global hydrogen economy and the impacts related to depletion of stratospheric ozone have been recently discussed in the scientific literature. However, the leak rates by technologies to be used in the hydrogen economy remain ill constrained. Very little data are available regarding hydrogen leak rates during the transfer operations, or at interfaces, and what data are available may not be particularly useful for consumer applications. For example, observed boil-off and venting rates (upwards of 50 percent in some cases) for the liquid hydrogen filling operations for NASA's Space Shuttle launches would not be acceptable for consumer operations, both from a safety and a cost perspective. On the other hand, we know that natural gas production and distribution systems have current leak rates of 1 to 5 percent, which could be reduced somewhat with technology and process improvements. The properties of hydrogen, particularly its high molecular diffusivity and small size, make achieving "zero emissions" of hydrogen improbable. Furthermore, lowering leak rates below a certain threshold will not be cost effective. Understanding the potential impacts of hydrogen on atmospheric chemistry (stratospheric ozone, global oxidative capacity, and air quality) will require an understanding of the possible leak points during production, transportation, storage, delivery, and use of hydrogen. This paper will examine several hydrogen infrastructure scenarios to identify and quantify, to the extent possible, the likely hydrogen emissions in a hydrogen economy. This will be used to make plausible assessments of the effect of a global hydrogen economy on the natural hydrogen cycle and atmospheric chemistry.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0322 Constituent sources and sinks
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting