MadSci Network: Engineering
Query:

Re: concrete holding hydrogen gas.

Date: Thu Nov 29 11:24:09 2001
Posted By: Leslie Allen, Staff, Laboratory Chemist, Valero Refining Company
Area of science: Engineering
ID: 1006229422.Eg
Message:

Your question was a little puzzling. Are your plans to build storage? 
Building storage for this material is best left to the experts. As far as 
concrete, there are many grades. Also, there are numerous techniques in 
designing storage devices. Hydrogen containment within concrete usually 
consists of steel walls which you haven't mentioned, nor the tank wall 
dimension.
Under these conditions, it is virtually impossible to provide KiSSGS data. 
So maybe a little background may help you with specifications on your 
theoretical tank design and compressor and refrigeration and ....
     Compressing hydrogen is similar to compressing natural gas, though as 
hydrogen is less dense the compressors need better seals. Hydrogen is 
normally compressed to between 200 and 250 bar for storage in cylindrical 
tanks of up to 50 litres. These tanks may be made from aluminium or 
carbon/graphite compounds. If the compressed hydrogen is to be used on a 
larger scale then pressures of 500-600 bar may be employed, though some of 
the largest compressed hydrogen tanks in the world (about 15,000 cu-m) use 
pressures of only 12-16 bar.
     In order to reduce the volume required to store a useful amount of 
hydrogen, liquefaction may be employed. Since hydrogen does not liquefy 
until it reaches -253C (20 degrees above absolute zero), the process is 
both long and energy intensive.
     Selection of the proper materials of construction for cryogenic 
service is one of the most important considerations. Of primary concern is 
how the material will perform at cryogenic temperatures. Fracture 
mechanics involving such properties as notch toughness, ductility, 
critical flaw sizes, specific heat, coefficients of thermal expansion and 
thermal conductivity at cryogenic temperatures, as well as the usual 
strength and elastic properties of the material, must be studied. 
The cryogenic industry recognized the need to study the subject of 
fracture mechanics as it applies to materials of construction for 
cryogenic service. CB&I, was one of the principal participants to study 
the properties of 9 percent nickel. Proper materials and techniques need 
be selected to meet requirements for cryogenic storage.

MATERIALS FOR LOW-TEMPERATURE TANKS (DOWN THROUGH -60F) 
ALLOWABLE STRESS (PSI)
Material.....Pressure
Designations.Storage
Number.......(ASME)
             psi(kg/cm2)

A516-55.......13,700 (963)
A16-60........15,000 (1055)
A516-65.......16,250 (1140)
A516-70.......17,500 (1230)
A537 Grade 1..17,500 (1230)
A537 Grade 2..20,000 (1405)
A737 Grade B..17,500 (1230)

Cryogenic Materials (THROUGH -450F) 
Stainless....18,750
Aluminum.....6,250 to 10,000
5%-9%Nickel....23,750












Current Queue | Current Queue for Engineering | Engineering archives

Try the links in the MadSci Library for more information on Engineering.



MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci


MadSci Network, webadmin@www.madsci.org
© 1995-2001. All rights reserved.