Randolph Kirchain - Academia.edu (original) (raw)

Papers by Randolph Kirchain

The minerals, metals & materials series, 2019

Understanding cobalt criticality and availability is necessary as lithium-ion battery demand, par... more Understanding cobalt criticality and availability is necessary as lithium-ion battery demand, particularly for electric vehicles, is projected to increase exponentially throughout the next decade. With these increases in demand, supply concentration and mining limitations could have a significant impact on cobalt-dependent firms, sectors, and emerging technologies. Increased recycling, cobalt refining capability, and possible substitution away from cobalt in high demand sectors form the basis of modeling scenarios; these scenarios are created to identify the implications of changes in the cobalt supply-demand balance to 2030. Based on these, cobalt faces a tight but not impossible short-term market, where recycling and additional cobalt sources should be pursued and will become increasingly important out to and past 2030.

This poster aims to show the importance of material availability for manufacturers, as well as pr... more This poster aims to show the importance of material availability for manufacturers, as well as provide methods to define and assess materials criticality, and tools to understand market dynamics in the short- and mid-term. These tools will help manufacturers make informed decisions about materials, and elaborate efficient strategies to mitigate the risks associated with a potential supply disruption or sustainability concerns.

SAE International Journal of Materials and Manufacturing, Apr 16, 2012

Environmental Science & Technology, Jun 3, 2016

Materials selection decisions exhibit great influence on the environmental performance of firms t... more Materials selection decisions exhibit great influence on the environmental performance of firms through their impact on processing technology, product form, and supply chain configuration. Consequently, materials dictate a product's environmental profile via the burden associated with extraction and refining, transformation from material to product, product performance characteristics during use, and potential recovery at end-of-life (EOL). While lifecycle assessment (LCA) methods provide quantitative input to a product designer's materials selection decision, LCA implementations are evolving and disparate. This work explores several analytical variations of LCA related to the allocation of recycling impacts at product EOL and the implications of these variants across a range of contexts. Stylized analyses across a range of materials are presented, focusing on materials with varying primary and secondary materials production burdens. This work illustrates that a) the application of distinct EOL allocation methods give different values of cumulative environmental impact for the same material, b) these impacts change at differing rates between the various methods, and c) these disparities can result in different rank ordering of materials preference. Characterizing this behavior over a range of parameters illustrates the potential trends in allocation method bias for or against particular materials classes. Index Terms-end-of-life, life cycle assessment, materials selection, recycling I. INTRODUCTION ndustries today deal with a range of environmental pressures that are diverse, dynamic, and demand new levels of accountability, financial commitment, and supply chain capabilities. Environmental pressures stem from four key sources, including regulations, resource accessibility, ethical responsibility, and consumer demand for environmentally

Transportation Research Part D-transport and Environment, Dec 1, 2013

We present a comparative life cycle assessment of pavements considering measurement uncertainty a... more We present a comparative life cycle assessment of pavements considering measurement uncertainty and the data-quality uncertainty. We account for the uncertainty due to the prediction of roughness over pavement lifetime and propagate the consequence into the overall footprint. The uncertainty propagation is conducted using a Monte Carlo simulation. Making use of a comparison indicator, the difference in the environmental impacts of two alternative designs is statistically characterized taking into account the correlation in the input parameters. The contribution of different phases and their associated uncertainty characterized and compared for two pavements.

International Journal of Production Economics, Jul 1, 2011

Composites Science and Technology, Jul 1, 2008

Previous studies on materials choice in automotive bodies have looked at both composite and alumi... more Previous studies on materials choice in automotive bodies have looked at both composite and aluminum alternatives, but have always found steel to be the most cost-effective option at the production volumes found in the overwhelming majority of vehicle models. This study finds composites to have significant economic potential when considering emerging advances in the polymer composite body-in-white design against the mild-grade steel body currently on the road. With the significant implications of a polymer composite body for vehicle light-weighting and thereby improved fuel efficiency, these results come at a time when they are particularly pertinent. The results presented in this paper are based on a consortium-developed, 25-part unibody design not available to previous studies. Also presented for the first time are data on competing alternatives in fiber composite component assembly and implications of platform sharing across vehicle models. Finally, developments in process-based cost modeling capabilities are presented for (a) fiber-reinforced composite component production, (b) component assembly, and (c) design implications of glass versus carbon reinforcement.

Environmental Science & Technology, Aug 29, 2007

Many authors suggest that market forces are inadequate to successfully manage the problems of res... more Many authors suggest that market forces are inadequate to successfully manage the problems of resource availability and use. The fundamental question is whether these inadequacies are intrinsic to the market or if they arise from a failure of firms to detect and respond to subtle market signals. This paper explores the latter by describing (1) mechanisms that can limit materials availability, (2) effects of such limits on the firm, (3) preliminary metrics to diagnose these risks, and (4) strategies to reduce a firm's risk exposure. Case analyses of two materials systems are used to suggest that private firm interests, when properly informed, can motivate strategies that drive toward sustainable materials use. These strategies include (1) improving production efficiency, (2) developing technology to use more sustainable substitute materials, and (3) facilitating a more effective materials recycling infrastructure.

Environmental Science & Technology, Apr 5, 2012

Social Science Research Network, Jan 31, 2010

Ecoinvent-Electricity, high voltage {US}| production mix Impact Uncertainty: Ecoinvent-Electricit... more Ecoinvent-Electricity, high voltage {US}| production mix Impact Uncertainty: Ecoinvent-Electricity, high voltage {US}| production mix Waste Oil Treated as zero-impact contributor Tire Derived Treated as zero-impact contributor Wood Treated as zero-impact contributor Transportation Conveyer unavailable Neglected from total (minimal amount used) Pipeline Ecoinvent-natural gas, pipeline, long distance/RER

Springer eBooks, Nov 7, 2012

ABSTRACT Recognition of the importance of climate change and energy security has led to interest ... more ABSTRACT Recognition of the importance of climate change and energy security has led to interest in electrified vehicles. Electrified vehicles contain substantial amounts of lithium and rare earth elements. There has been concern that the supplies of lithium may not be sufficient to support the development of a large scale global fleet of electric vehicles. We conducted a comprehensive analysis of the global lithium resources and compared it to an assessment of global lithium demand from 2010 to 2100 that assumes rapid and widespread adoption of electrified vehicles. We show that that even with rapid and widespread adoption of electric vehicles powered by lithium-ion batteries lithium resources are sufficient to support demand until at least 2100. 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 evaluated potential future demand scenarios for REEs with a focus on the issue of co-mining. 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 CO2 at 450 ppm may lead to an increase in demand of more than 700 and 2,600 % for Nd and Dy, respectively, over the next 25 years.

Journal of Sustainable Metallurgy, Nov 2, 2016

Increased use of secondary raw materials in metals production offers several benefits including r... more Increased use of secondary raw materials in metals production offers several benefits including reduced cost and lowered energy burden. The lower cost of secondary or scrap materials is accompanied by an increased uncertainty in elemental composition. This increased uncertainty for different scraps, if not managed well, results in increased risk that the elemental concentrations in the final products fall outside customer specifications. Previous results show that incorporating this uncertainty explicitly into batch planning can modify the potential use of scrap materials while managing risk. Chance constrained formulations provide one approach to uncertainty-aware batch planning; however typical formulations assume normal distributions to represent the compositional uncertainty of the materials. Compositional variation in scrap materials has been shown to have a skewed distribution and, therefore, the performance of these models, in terms of their ability to provide effective planning, may then be heavily influenced by the structure of the compositional data used. To address this issue, this work developed several approximations for skewed distributional forms within chance constrained formulations. We explored a lognormal approximation based on Fenton's method; a convex approximation based on Bernstein inequalities; and a linear approximation using fuzzy set theory. Each of these methods was formulated 2 and case studies executed using compositional data from an aluminum remelter. Results indicate that the relationship between the underlying structure/distribution of the compositional data and how these distributions are formulated in batch planning can modify the use of secondary raw materials.

Increased recycling, product redesign and substitution can improve firm resilience in the face of... more Increased recycling, product redesign and substitution can improve firm resilience in the face of uncertainties in materials availability. The delays involved in implementing these strategies may result in unprepared firms losing market share to competitors who are better prepared to address these challenges. This paper will expand from previous work in this area by examining the statistical significance of the effect of recycling in the face of limited supply. It has been shown that the timing and magnitude of a supply shutdown can influence the magnitude of price response. On average, increased recycling is a means for stabilizing price effects owing to its faster response times.

Airfield and Highway Pavements 2019, 2019

In 2009, the US cement and concrete industries established the Concrete Sustainability Hub at the... more In 2009, the US cement and concrete industries established the Concrete Sustainability Hub at the Massachusetts Institute of Technology. A primary thrust of MIT's activities has been improving the Life Cycle Assessment practices to better quantify the environmental impacts over the life of a pavement. In their research, the MIT CSHub determined that the "use phase" can dominate the materials, construction and maintenance phases of a pavement LCA and that two of the important factors in the use phase are Pavement Vehicle Interaction (PVI) and Albedo. PVI describes the excess fuel emissions / energy from vehicles due to excess rolling resistance between the pavement and the vehicle. Albedo is the fraction of solar energy reflected by the Earth's surface, with lighter color, higher albedo surfaces reflecting more energy than lower albedo, darker surfaces. This paper will summarize the CSHub Use Phase research findings to date.

ArXiv, 2019

Concrete is the most widely used engineered material in the world with more than 10 billion tons ... more Concrete is the most widely used engineered material in the world with more than 10 billion tons produced annually. Unfortunately, with that scale comes a significant burden in terms of energy, water, and release of greenhouse gases and other pollutants. As such, there is interest in creating concrete formulas that minimize this environmental burden, while satisfying engineering performance requirements. Recent advances in artificial intelligence have enabled machines to generate highly plausible artifacts, such as images of realistic looking faces. Semi-supervised generative models allow generation of artifacts with specific, desired characteristics. In this work, we use Conditional Variational Autoencoders (CVAE), a type of semi-supervised generative model, to discover concrete formulas with desired properties. Our model is trained using open data from the UCI Machine Learning Repository joined with environmental impact data computed using a web-based tool. We demonstrate CVAEs ca...