Title: Superconductivity in hydrogenbased energy applications
1Superconductivity in hydrogen-based energy
applications
P. Mikheenko, W. Cui and J. S. Abell
Metallurgy and Materials, School of Engineering,
University of Birmingham, Edgbaston, Birmingham
B15 2TT, UK
2Reasons for a hydrogen-based economy
? Limited fossil fuels - need of alternative
fuel. The supply of oil will start decreasing in
2010. At current rates of use, proven reserves
of coal will last for 160 years, natural gas for
70 years and oil for 40 years. ? Global
warming - need of clean fuel, necessity of
reforming natural gas, including sea-floor and
permafrost deposits of methane that otherwise
will contribute to global warming. ? Methane is
increasingly escaping from ocean floors and is 21
times more capable of trapping heat in the
atmosphere than carbon dioxide. ? Slight
increase of the temperature can lead to a
substantial increase of methanogenic activity of
micro-organisms in arctic permafrost.
3Development of a hydrogen-based economy
? Hydrogen production reforming of natural gas,
gasification of coal and biomass electrolysis of
water photo-electrolysis biological production
high temperature decomposition of carbohydrates ?
Storage of hydrogen compressed gas liquid
hydrogen solid state storage (metal hydrates,
high surface area materials) liquid storage
(NaBH4, organic liquids) ? Building global
infrastructure, incorporating current electrical
energy system ? Liquid hydrogen and
superconductivity
4Superconducting pipelines transport of liquid
hydrogen and electrical energy, levitating train
Magnetic field 1 Tesla
5Superconducting materials for a hydrogen-based
economy
? High temperature superconductors (1986), Tc gt90
K, thin films ? MgB2 (2001), Tc 39 K, bulk ?
Fullerenes, C60 (1991) Tc up to 40 K for Cs3C60
and between 60 K and 70 K for C60 doped with the
inter-halogen compound ICl (1993) ? Fe-based
superconductors (2008), LaO1- xFxFeAs, in F-doped
Pr compound Tc is 52 K ? Not yet discovered
superconductors
6Combined transport of liquid hydrogen and
electricity in MgB2 pipelines
106 A/cm2, 20 K, 230 V one pipeline with
inner diameter (D) of 18 cm and outer D of 20 cm
power 13.7 GW, about 1/30 of the average
power consumed in UK
H I/(pD), B ?0H, ?0 4p 10-7 (T m/A)
B (T) 410-7I(A)/D(m)
Current 6 107 A - magnetic induction B 120 T
30 times reduction in current - magnetic
induction 4 T, able to transport 460 MW the
power of an average power station.
7Methods for preparation of MgB2 Hot Isostatic
Pressing (HIP) and Resistive Sintering (RS)
Typical RS sample size 5 mm ? x 2 mm
Typical HIP sample size 13 -25 mm ? x 4 cm
8Advantages of MgB2
High critical temperature (40 K, twice above
boiling temperature of liquid hydrogen, 20.3
K) High critical current in bulk ( 106 A/cm2
at 20 K) Low mass density ( 2.62 g/cm3)
9Additional energy applications of MgB2
? The liquid hydrogen can be moved along the
pipes by the energy efficient superconducting
MgB2 motors ? The control of the flow can be
made by the superconducting MgB2 electronics ?
Temporary the energy can be stored in MgB2-based
superconducting magnetic energy storage systems
(SMES) or flying MgB2 wheels ? MgB2 fault
current limiters will protect the system from
overload
10MgB2 joining technique
MgB2 joining technique is based on the tolerance
of MgB2 to misorientations of grains. Moreover,
the higher the misorientations, the larger is the
critical current in MgB2. Special temperature and
pressure conditions are necessary to form a
superconducting joint
11Properties of superconducting MgB2 joint
MgB2 joint has a large cross-section, is strong
mechanically and shows only a small reduction of
critical current density through the area of the
joint
12Use of high temperature superconductors in
hydrogen energy applications
LaAlO3
HTS must be strongly aligned. Highly textured
substrate materials are required for coating.
Chemical fluorine-free routes are preferable
13Properties of dip-coated HTS covers
Dip-coated samples show narrow superconducting
transition at T above 90 K and their critical
current density is approaching that of pulsed
laser deposited films
14Conclusions
The development of a hydrogen economy with a
focus on transportation and storage of hydrogen
in liquid form gives a unique opportunity to
introduce superconductivity on the global scale
into virtually every area of human activity,
transport and households. It will make energy
economy cleaner, safer, more reliable and
efficient First global application of
superconductors is expected to be in pipeline
infrastructure for simultaneous transport of
electrical energy and liquid hydrogen.
Superconducting cars, planes and submarines can
be developed in a few years from now HTS and
MgB2 are most likely to be the most widespread
superconducting materials Important
technological advances have been made by
developing the superconducting MgB2 joint and
cheap HTS coating methods