Monday, July 12, 2010

Permanent Resource Crisis?

The amount and types of materials needed to implement low- or zero carbon based technologies for a weakly sustainable economy already point to the beginning of a series of resource crises (‘permanent resource crises’).

The rare earth metals have abundances on the order of parts-per-million in the earth’s crust. While the elements of this group of 15 metals are not as rare as their name indicates, their 2007 world demand of 110,000 tons, of which 90% comes from China, is used in many high-tech products and processes, including ceramics and pigments (7%), catalysis, including automotive catalytic converters (20%), phosphors for compact fluorescent and solid state lighting (LEDs) (7%), the glass and polishing industry (25%), permanent magnets such as Nd-Fe-B and SmCo5 (35%) and other applications such as the newly identified need for neodymium (Nd) for wind turbine systems and as unrefined mixtures called ‘mischmetal’ in nickel hydride batteries (6%)[1]. Many of these uses are center stage in green technologies and their demand is likely to outpace supply within a very short time.

The price of rare earth metals has been going up in the last decade, due to the limited supply (controlled by the Chinese government) and the growing demand for phosphors for lighting applications. The anticipated ban of incandescent lamps in Australia and Europe, and the push for compact fluorescent lamps in the short term has already put enormous pressure on rare earth supplies and prices. A full ‘green lighting switch’ will double the required volume of phosphors containing rare earth metals. We also anticipate a continued demand for flat plate TV screens: a continuous growth rate of 15-20% for large size flat displays is projected over the next few years. There is already a shortage of Terbium (Tb), needed for green phosphors, and Europium (Eu), used for red and blue phosphors. At most about 40% of additional Tb (~50 tons) and 75% of Eu (~130 tons) will be available by 2015.

Recycling 10-15% of the current world supply of Tb and Eu is an absolute must for addressing this materials shortage in the short to mid-term – but there is currently no agreed upon process for efficiently collecting and recycling rare earth metals from lighting phosphors.Other strategic materials needed to implement green and nanotechnologies which are currently resource limited are silver, tellurium and indium (for thin film photovoltaic devices), platinum (needed for fuel cells), and lithium (for lithium based batteries).

[1] Jean-PierreCuif, Rhodia, Global Phosphor Summit 2008

1 comment:

  1. Thank you for sharing this information.
    It will really helpful to solve my confusion

    Process $ Chemical Engineering