Distribution, hydrogen

The transition towards the so-called hydrogen economy requires the development of infrastructure plans. Currently, few limited networks for hydrogen utilization exist in the world, mostly concentrated in Europe (UK, Netherlands, Germany) and USA, and located close to refinery site for petrochemical or other industrial requirements. 

A future massive network can be realized according to two possible scenarios  

a centralized management of the worldwide hydrogen production and distribution, corresponding to the existent energy production strategies 

a distributed territorial production and utilization, for which H2 is produced onsite at small-medium-scale filling station. 

The analysis of the above strategies needs to include all the stages necessai y to produce and distribute the fuel for a widespread use, and should benefit from the following two options for hydrogen transport and distribution  

Once hydrogen is produced at a centralized facility, it must be delivered to the fueling station. Depending on the delivery method, there may be storage costs at both the production facility and fueling station. The delivery cost can be quite expensive, and may determine the overall viability of the hydrogen option. This section outlines the various options for distribution and how these options are included in HjSim. 

The storage and transportation cost results from Amos analysis are compared to the results from Simbeck and Chang s analysis in Table 7.1. This comparison assumes a production rate of 150000 kg/ day (enough to serve approximately 225 000 vehicles), storage time of 12 h, compression from 1 MPa (145 psi) to 21.5 MPa (3000 psi) and a transport distance of 150 km. A transport pressure of 3000 psi is lower than the expected 5000-10 000 psi range of pressures for use in vehicles. 

The SFA results are significantly higher than those presented by Amos, and highlight the huge degree of uncertainty associated with various transport options. For example, whereas Amos estimates hydrogen could be delivered for about 0.10 /kg by pipeline, the SFA study estimates costs of 2.94 /kg. They do follow a similar pattern, with 

This section outlines the equations used in the model to determine the costs associated with on-site hydrogen storage and transportation. While several of these equations are from the Amos study, others were derived by the modeling team or other sources, as indicated. When using Amos work, we included the cost of capital financing, which Amos did not. 

These variables are used to determine costs associated with hydrogen compression for both types of gaseous storage using a multistage compressor. The energy required (kW) for isothermal compression is a function of the production rate as well as the inlet and outlet pressures 

Michael Ball, Werner Weindorf and Ulrich Biinger 

An area-wide supply of hydrogen will, in the medium to long term, require the implementation of an extensive transport and distribution infrastructure. In addition, a dense network of refuelling stations will have to be put in place. This chapter first addresses the various options for hydrogen transport and their characteristics. Subsequently, different fuelling station concepts will be discussed. 

The Hydrogen Economy Opportunities and Challenges, ed. Michael Ball and Martin Wietschel. Published by Cambridge University Press. Cambridge University Press 2009. 

For this reason, electrolysers or steam reformers, which supply hydrogen at ambient pressure, would not be used. Compression costs have been calculated based on the assumption that hydrogen is available at a minimum pressure of 30 bar from any production technology and that the pipeline outlet pressure is also 30 bar. 

For transporting hydrogen by pipeline, three principal options exist  

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This stress-strain behavior is consistent with the optic metallographic data which evidenced partial redistribution of hydrogen over the powder particles when the compacting temperature was increased to 400°C and uniform hydrogen distribution on additional annealing or during plastic deformation at T > 500°C. 

The observed hydrogen distribution is consistent with mechanism (8.44AB). 

To overcome the shortcomings of interpreting the SIMS data on hydrogen distribution in anodic aluminas, Lanford et al214 have... 

The onboard hydrogen supplied from organic chemical hydrides will be utilized well in the ICE vehicles. Even for stationary use of hydrogen, distribution of organic chemical hydrides will play an important role at stations or sites, where waste heat at modest temperatures is dissipated in vain without chemical recuperation. 

Fig. 10. Hydrogen distribution in c-Si after annealing at the indicated temperature. The solid line indicates the initial (as implanted) distribution. [Courtesy of C.W. Magee and C.P. Wu]...

More complicated is the evolution of the hydrogen distribution in situations where the electrostatic potential distribution is affected not only by... 

Recent channeling studies have been interpreted to indicate H—B pairs with hydrogen distributed between both the BC and Si—AB sites, with a preference for the BC site at low temperatures. (Marwick et al., 1987, 1988 Bech Nielsen et al., 1988). The boron is estimated to be off the substitutional site by roughly 0.2-0.3 A. This is consistent with the PAC measurements of the similar H—In pair, where the Si—AB site is favored at higher temperatures (T > 150 K), but the BC site is favored at lower temperatures (Wichert et al., 1987, 1988 Wichert, 1988). Also from the PAC studies, the H—In defect is found to anneal with a dissociation barrier estimated to be about 1.3 eV (Wichert et al., 1987). 

Valves, the use of which may be necessary for the safe operation of a hydrogen distribution system, shall be checked and serviced, including lubrication where necessary, at sufficiently frequent intervals to assure their satisfactory operation. Examination shall include checking of alignment to permit use of a key or wrench and clearing from the valve box or vault any debris that would interfere with or delay the operation of the valve. Valves in hydrogen service shall be checked and serviced at least annually. 

Each operating company having a hydrogen distribution system shall set up, in its operating and maintenance plan, a provision for the making of periodic leakage surveys on the system. 

Chapter 12 discusses and analyses the different options for hydrogen distribution -pipelines and trailers (including liquefaction) - from a technical and economic point of view, in the same way as the hydrogen production technologies in Chapter 10. Further, different hydrogen refuelling station concepts are described and the necessity for the development of codes and standards addressed. 

Hydrogen distribution Table 12.2. Technoeconomic data of hydrogen liquefaction... 

Mintz, M., Molburg, J., Folga, S. and Gilette, J. (2002). Hydrogen Distribution Infrastructure. Research paper. Argonne Argonne National Laboratory, Transportation Technology R D Centre. 

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