Large-scale Storage

Short-term storage in depleted gas fields is considerably cheaper than in aquifers, for the following reasons. The geology has already been established and the field surveyed. There is confidence that the gas will not leak from the store without the requirement for a detailed appraisal. Since the reservoir will already be full of gas at low pressure, there will be no need to provide an initial charge (so-called cushion gas ) so that most of the gas that is injected can be recovered. Finally, much of the necessary equipment and the transport pipeline are likely still to be in place. By contrast, aquifers provide none of these advantages and much work will be involved in their evaluation and inauguration as gas stores. 

Hydrogen is rather more difficult to contain than natural gas on account of the smaller size of its molecule and its higher diffusion coefficient, both of which are factors that would tend to facilitate escape from the store. Fortunately, the pores in the caprock are sufficiently fine that the water they retain is not readily displaced, provided that the gas pressure is not excessive. The high diffusion coefficient of hydrogen should even assist the filling and emptying of the reservoir. 

95% pure hydrogen at 50 MPa pressure in old salt mines at Teesside, UK. These were formed by the leaching of 20-30m thick layers of rock salt at a depth of 350—600 m. Salt caverns can be filled and emptied much faster than stores that rely on permeation through porous rock, a distinct operational advantage. On the other hand, they suffer from the same limitation as aquifers, namely, the initial charge of gas at atmospheric pressure (cushion gas) is irrecoverable. 

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Large-scale storage containers are usually of metal and equipped with pressure-relief systems. 

To estimate the large-scale storage capacity of 45 important coal basins during Enhanced Coal Bed Methane Recovery (ECBM) in China, Li et al. used an equation which can be modified to a simpler form without considering the different coal bed basins [63, 79]. 

Studies have indicated that large-scale storage could take place with gaseous hydrogen underground in aquifers, depleted petroleum or natural gas reservoirs or man made caverns from mining operations. One of... 

Was this youT answer Nuclear fission reactors generate large amounts of radioactive wastes that require permanent, large-scale storage facilities. 

Chemical Industry Association. 1975. Code of Practice for Large-Scale Storage of Fully Refrigerated Anhydrous Ammonia in the United Kingdom. London Chemical Industry Association. 

Davidson B etal., 2000, Large Scale Storage Solution Regenesys Regenerative Euel Cell. Renewable Energy World, Jan/Eeb. 

Safety Recommendations for Large Scale Storage of Ammonia... 

Liqmds that boil at relatively low temperatures are often stored as liquids under their vapor pressures, which at ambient temperature can be quite large. Thus, n-butane stored as a liquid/vapor system is at a pressure of 2.581 barfora temperature of 300 K. Large-scale storage (>50 m ) of tliis kind is sometimes done in spherical tanks. Suggest two reasons why. 

The process is appealing as H2 is excellent for fuel cells in both electricity generation and vehicles and overall energy conversion efficiencies are over 60%. The downside is that large-scale storage and transport of H2 is difficult although research is looking into how... 

Metal hydride alloys for distributed storage and transportation Development of hydrogen absorbing alloys for - automobiles - compact stationary storage tank - large-scale storage system Development of alloys for commercial use... 

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