4 research outputs found
Comparative Analysis of Supply Risk-Mitigation Strategies for Critical Byproduct Minerals: A Case Study of Tellurium
Materials criticality assessment
is a screening framework increasingly
applied to identify materials of importance that face
scarcity risks. Although these assessments highlight
materials for the implicit purpose of informing future action, the
aggregated nature of their findings make them difficult to use for guidance in developing nuanced mitigation strategy and policy response.
As a first step in the selection of mitigation strategies, the present
work proposes a modeling framework and accompanying set of metrics
to directly compare strategies by measuring effectiveness of risk
reduction as a function of the features of projected supply demand
balance over time. The work focuses on byproduct materials, whose
criticality is particularly important to understand because their
supplies are inherently less responsive to market balancing forces, i.e., price
feedbacks. Tellurium, a byproduct of copper refining, which is critical
to solar photovoltaics, is chosen as a case study, and three commonly
discussed byproduct-relevant strategies are selected: dematerialization
of end-use product, byproduct yield improvement, and end-of-life recycling
rate improvement. Results suggest that dematerialization will be nearly
twice as effective at reducing supply risk as the next best option,
yield improvement. Finally, due to its infrequent use at present and its dependence upon long product lifespans, recycling end-of-life products
is expected to be the least effective option despite potentially offering
other benefits (e.g., cost savings and environmental impact reduction)
Platinum Availability for Future Automotive Technologies
Platinum is an excellent catalyst,
can be used at high temperatures,
and is stable in many aggressive chemical environments. Consequently,
platinum is used in many current industrial applications, notably
automotive catalytic converters, and prospective vehicle fuel cells
are expected to rely upon it. Between 2005 and 2010, the automotive
industry used approximately 40% of mined platinum. Future automotive
industry growth and automotive sales shifts toward new technologies
could significantly alter platinum demand. The potential risks for
decreased platinum availability are evaluated, using an analysis of
platinum market characteristics that describes platinum’s geophysical
constraints, institutional efficiency, and dynamic responsiveness.
Results show that platinum demand for an automotive fleet that meets
450 ppm greenhouse gas stabilization goals would require within 10%
of historical growth rates of platinum supply before 2025. However,
such a fleet, due largely to sales growth in fuel cell vehicles, will
more strongly constrain platinum supply in the 2050 time period. While
current platinum reserves are sufficient to satisfy this increased
demand, decreasing platinum ore grade and continued concentration
of platinum supply in a single geographic area are availability risk
factors to platinum end-users
Evaluating the Potential for Secondary Mass Savings in Vehicle Lightweighting
Secondary mass savings are mass reductions that may be
achieved
in supporting (load-bearing) vehicle parts when the gross vehicle
mass (GVM) is reduced. Mass decompounding is the process by which
it is possible to identify further reductions when secondary mass
savings result in further reduction of GVM. Maximizing secondary mass
savings (SMS) is a key tool for maximizing vehicle fuel economy. In
today’s industry, the most complex parts, which require significant
design detail (and cost), are designed first and frozen while the
rest of the development process progresses. This paper presents a
tool for estimating SMS potential early in the design process and
shows how use of the tool to set SMS targets early, before subsystems
become locked in, maximizes mass savings. The potential for SMS in
current passenger vehicles is estimated with an empirical model using
engineering analysis of vehicle components to determine mass-dependency.
Identified mass-dependent components are grouped into subsystems,
and linear regression is performed on subsystem mass as a function
of GVM. A Monte Carlo simulation is performed to determine the mean
and 5th and 95th percentiles for the SMS potential per kilogram of
primary mass saved. The model projects that the mean theoretical secondary
mass savings potential is 0.95 kg for every 1 kg of primary mass saved,
with the 5th percentile at 0.77 kg/kg when all components are available
for redesign. The model was used to explore an alternative scenario
where realistic manufacturing and design limitations were implemented.
In this case study, four key subsystems (of 13 total) were locked-in
and this reduced the SMS potential to a mean of 0.12 kg/kg with a
5th percentile of 0.1 kg/kg. Clearly, to maximize the impact of mass
reduction, targets need to be established before subsystems become
locked in
Evaluating Rare Earth Element Availability: A Case with Revolutionary Demand from Clean Technologies
The future availability of rare earth elements (REEs)
is of concern
due to monopolistic supply conditions, environmentally unsustainable
mining practices, and rapid demand growth. We present an evaluation
of potential future demand scenarios for REEs with a focus on the
issue of comining. Many assumptions were made to simplify the analysis,
but the scenarios identify some key variables that could affect future
rare earth markets and market behavior. Increased use of wind energy
and electric vehicles are key elements of a more sustainable future.
However, since present technologies for electric vehicles and wind
turbines rely heavily on dysprosium (Dy) and neodymium (Nd), in rare-earth
magnets, future adoption of these technologies may result in large
and disproportionate increases in the demand for these two elements.
For this study, upper and lower bound usage projections for REE in
these applications were developed to evaluate the state of future
REE supply availability. In the absence of efficient reuse and recycling or the development of technologies which use lower amounts of Dy and Nd, following a path consistent with stabilization of atmospheric CO<sub>2</sub> at 450 ppm may lead to an increase of more than 700% and 2600% for Nd and Dy, respectively, over the next 25 years if the present REE needs in automotive and wind applications are representative of future needs