New Techniques for Assessing Critical Raw Material Aspects in Energy and Other Technologies.

Transitioning to more sustainable energy technologies is a vital step in the move toward reducing global greenhouse gas emissions. However, several physical constraints could hinder the implementation of these technologies, and many of the raw materials required to produce new infrastructure are scarce, nonrenewable, and nonsubstitutable. Various factors relating to material extraction and processing activities may also affect the security and sociopolitical aspects of future supply lines. Here, we introduce methods for quantifying three key indicators relating to raw material supplies for specific production processes: (1) overall supply risk, (2) environmental impacts from sourcing raw materials, and (3) environmental justice threats at sourcing locations. The use of the proposed methods is demonstrated via an exploratory case study examining projected electricity production scenarios within the European Union. Results suggest that renewable sources of electricity─particularly wind, solar, and geothermal technologies─are more likely to exacerbate supply risks and environmental issues than other technologies. Furthermore, projected expansions of wind and solar technologies mean that all three indicators appear likely to rise significantly systemwide by 2050. Ultimately, the methods represent a much-needed first attempt at providing practitioners with simple and robust approaches for integrating factors relating specifically to raw material supply into energy modeling and other applications.

Advances towards circular economy policies in the EU: The new Ecodesign regulation of enterprise servers.

The concept of a circular economy has been widely accepted by governments and industries. In Europe, the European Commission adopted the Circular Economy package in 2015. The Ecodesign Directive has been identified as one of the most suitable legislative tools for achieving some of the objectives in the package because it has the potential to translate the circular economy principles into specific product material efficiency requirements. This paper applies the Ecodesign policy process to "enterprise servers" to illustrate how circular economy strategies can be implemented by European product policies. Indeed, the paper introduces a potential novel approach to "operationalize" circular economy principles in product policies. The evolution of the material efficiency requirements for a more circular economy is described up to their final formulation, which is the one in the published Ecodesign regulation. This legal act includes requirements on design for disassembly, firmware availability, data deletion, and presence of critical raw materials. The process for enterprise servers has been successful as the early discussions between stakeholders, policymakers and experts, supported by appropriate metrics along an iterative debate, comes to the publications of material efficiency requirements in a regulation. This study represents a 'first-of-a-kind' experience, and sets precedents for the development of similar requirements for other product groups.

Accounting for the environmental benefits of remanufactured products: Method and application.

Although the importance of reusing products has been stated frequently, both in legislation and by academics, the scientific literature does not provide comprehensive and systematic methods of assessing the reuse of a generic product from an environmental point of view. Moreover, the definitions of reuse provided in the literature and legislation are not always consistent. This article introduces an original classification of different types of reuse, including some suggested definitions. It then focuses on remanufacturing, a type of reuse in which a used product (or its components) is returned to at least its original performance level. The article describes the development of a method for assessing, from a life-cycle perspective, the potential environmental benefits of remanufacturing energy-related products. The method includes several novel aspects: it helps to analyse possible trade-offs between potential environmental impacts and energy efficiency; it allows the independent modelling of some parameters that influence product reuse; and it can be applied even at the early stages of the design process, when some specifications may not yet have been defined. The environmental impacts of a product's life-cycle stages are used as input parameters for the assessment. The method is then applied to an enterprise server, a case-study product for which remanufacturing is a current market practice. A sensitivity analysis is included to check how uncertainties could affect the overall results. The results of the case study show that remanufactured servers, even those that are less energy efficient, can have lower environmental impacts than new ones. For example, reusing some components (e.g. hard disk drives and memory cards) is environmentally beneficial even if the remanufactured server consumes up to 7% more energy than a newly manufactured server. The case study also demonstrates how the method proposed could be used in the context of product policy discussions.

Exergy efficiency in industry: where do we stand?

Efficiency is a term generally used to determine how well a system performs. However, efficiency can have different meanings and, unaccompanied by a formal definition or taken out of context, can lead to serious misconceptions. In many official publications, efficiency is calculated as the ratio of useful output to energy input. This measure reflects the first law of thermodynamics (conservation of energy) but does not reflect the potential for improvement. A better measure, that also reflects the second law of thermodynamics, is the ratio of the potential useful (exergy) output to the potential useful (exergy) input. We estimate second law efficiencies for the inorganic and organic chemical industries to be 29% and 35% respectively. We also estimate the efficiency of the U.S. industry sector as a whole to be 37.6%, as compared to only 7.7% for the overall U.S. economy. These figures are far lower than the "first law" figures published by the U.S. Department of Energy (80% for industry and 42.5% overall) and they imply a significant potential for improvement.

Exergy analysis of integrated waste management in the recovery and recycling of used cooking oils.

Used cooking oil (UCO) is a domestic waste generated daily by food industries, restaurants, and households. It is estimated that in Europe 5 kg of UCO are generated per inhabitant, totalling 2.5 million metric tons per year. Recovering UCO for the production of biodiesel offers a way of minimizing and avoiding this waste and related pollution. An exergy analysis of the integrated waste management (IWM) scheme for UCO is used to evaluate such a possibility by accounting for inputs and outputs in each stage, calculating the exergy loss and the resource input and quantifying the possible improvements. The IWM includes the collection, pretreatment, and delivery of UCO and the production of biodiesel. The results show that the greatest exergy loss occurs during the transport stages (57%). Such exergy loss can be minimized to 20% by exploiting the full capacity of collecting vans and using biodiesel in the transport stages. Further, the cumulative exergy consumption helps study how the exergy consumption of biodiesel can be further reduced by using methanol obtained from biogas in the transesterification stage. Finally, the paper discusses how increasing the collection of UCO helps minimize uncontrolled used oil disposal and consequently provides a sustainable process for biodiesel production.