Decision Support through Mass and Energy Flow Management in the Vehicle-Refinishing Sector

In the past few decades, major advances in environmental protection within the coating application industry have been made. In spite of this technological progress, approximately 50% of industrial-solvent emissions still come from the paint-application sector. The advances made in reducing emissions for plants requiring licensing have unfortunately had no influence on the environmental efforts of smaller companies. Solvent-reduced painting systems, such as high-solid paints, water-based coating, and powder coating have not been able to achieve acceptance, nor have innovative application technologies. The principal arguments against a conversion to these ecologically more favorable alternatives were related to cost and quality.
Recently, the EU Solvent Directive (1999/13/EC) went into effect, aiming to significantly reduce industrial-solvent emissions. Up until this point, however, instruments enabling smaller companies to determine their solvent emissions and to simultaneously develop process-improvement potentials while keeping costs in mind have been missing.
Using the mass and energy flow-management approach, cost structures and environmental benefits can be made transparent to the entrepreneur. The primary result of the research projects presented here is the computer-based mass and energy flow model called the individual computer-aided mass and energy flow model for the vehicle-refinishing sector (IMPROVE). It can be used as a detailed business-consultancy tool. Based upon this, practical guidelines were developed for easy orientation and activity planning. They can be used by companies to help them fulfill the requirements of environmental legislation and to display the benefits that can be achieved by various emission-reduction measures.     

Assessment of the Automobile Assembly Paint Process for Energy, Environmental, and Economic Improvement

A coat of paint adds considerable value to an automobile. In addition to consuming up to 60% of the energy needed by automobile assembly plants, however, the painting process also creates both economic and environmental impacts. This study investigated the degree of cost and environmental impact improvement that can be expected when modifications are considered for existing paint processes through heat integration. In order to accomplish this goal, a mathematical model was created to describe the energy use, costs, and environmental impacts from energy consumption in an automobile assembly painting facility. The model agrees with measured energy consumption data for process heating and electricity demand to within about 15% for one Michigan truck facility from which model input parameters were obtained. Thermal pinch analysis determined an energy conservation target of 58% of paint process energy demand. A heat exchanger network optimization study was conducted in order to determine how closely the network design could achieve this target. The resulting heat exchanger network design was profitable based on a discounted cash flow analysis and may achieve reductions in total corporate energy consumption of up to 16% if implemented corporatewide at a major automobile manufacturer.     

End-of-Life Infrastructure Economics for "Clean Vehicles" in the United States

Rising fuel prices and concern over emissions are prompting automakers and legislators to introduce and evaluate "clean vehicles" throughout the United States. Hybrid electric vehicles (HEVs) are now on the roads, electric vehicles (EVs) have been test marketed, and niche vehicles such as high-fuel-economy microcars are being considered for introduction. As these vehicles proliferate and mature, they will eventually reach their end of life (EOL). In the United States, an extensive recycling infrastructure exists for conventional, internal combustion engine (ICE) vehicles. Its primary constituents are the disassembler and the shredder. These industries, as well as battery recyclers, are expected to play integral roles in the EOL processing of clean vehicles.
A model of the automobile-recycling infrastructure and goal programming techniques are used to assess the materials streams and process profitabilities for several different clean vehicles. Two-seat EVs with lead-acid or NiMH batteries are compared with two- and four-seat HEVs and microcars. Changes to the nonferrous content in the vehicle bodies are explored and compared for the effect on processing profit-ability. Despite limitations associated with the linearity of goal programming techniques, application of this tool can still provide informative first-order results. Results indicate that although these clean vehicles may not garner the same profit levels as conventional ICE vehicles, they are profitable to process if there are markets for parts and if there are sufficient quantities of nonferrous materials.     

Life Cycle Energy and Greenhouse Gas Emissions of Automobiles Using Aluminum in China

Transportation is a major part of energy consumption and greenhouse gas (GHG) emissions. Aluminum (Al) as a light metal can reduce vehicle weight, energy consumption, and pollutant emissions, but Al production is energy intensive. The main contents of this study are the following: (1) create the life cycle inventory of Al parts based on the energy background in China and (2) evaluate the energy savings and GHG reduction for the vehicle when steel parts are replaced by Al parts. Although there is a considerable reduction in energy consumption of per tonne Al in China owing to continuing development of process technology in recent years, energy consumption is higher than the world average level and European level. Over the vehicle's life cycle driving of 200,000 kilometers, the vehicle was found to avoid 1,447 to 1,590 liters of gasoline consumption when six typical steel parts were replaced by Al parts. Based on the current technology, the breakeven distance was calculated, resulting in a net energy benefit to use the lightweight Al parts compared with steel parts. A sensitivity analysis was conducted to show different energy savings by considering secondary weight reduction and different driving distance. The results indicate that weight reduction by using Al is quite effective to reduce the energy consumption and GHG of transportation.     

Vehicles and Critical Raw Materials: A Sustainability Assessment Using Thermodynamic Rarity

The changing material composition of cars represents a challenge for future recycling of end‐of‐life vehicles (ELVs). Particularly, as current recycling targets are based solely on mass, critical metals increasingly used in cars might be lost during recycling processes, due to their small mass compared to bulk metals such as Fe and Al. We investigate a complementary indicator to material value in passenger vehicles based on exergy. The indicator is called thermodynamic rarity and represents the exergy cost (GJ) needed for producing a given material from bare rock to the market. According to our results, the thermodynamic rarity of critical metals used in cars, in most cases, supersedes that of the bulk metals that are the current focus of ELV recycling. While Fe, Al, and Cu account for more than 90% of the car's metal content, they only represent 60% of the total rarity of a car. In contrast, while Mo, Co, Nb, and Ni account for less than 1% of the car's metal content, their contribution to the car's rarity is larger than 7%. Rarity increases with the electrification level due to the greater amount of critical metals used; specifically, due to an increased use of (1) Al alloys are mainly used in the car's body‐in‐white of electric cars for light‐weighting purposes, (2) Cu in car electronics, and (3) Co, Li, Ni, and rare earth metals (La, Nd, and Pr) in Li‐ion and NiMH batteries.     

Informing Packaging Design Decisions at Toyota Motor Sales Using Life Cycle Assessment and Costing

Throughout their life cycle stages—material production, package manufacture, distribution, end-of-life management—packaging systems consume natural resources and energy, generate waste, and emit pollutants. Each of these stages also carries a financial cost. Motivated by a desire to decrease environmental burdens while reducing financial costs associated with the packaging of accessory and service parts, Toyota Motor Sales (TMS) partnered with the Donald Bren School of Environmental Science & Management to build a life cycle assessment and costing tool to support packaging design decisions. The resulting Environmental Packaging Impact Calculator (EPIC) provides comprehensive life cycle assessment (LCA) and life cycle costing (LCC). It allows packaging designers to identify environmentally and economically preferable packaging systems in daily decision-making. EPIC's parameterized process flow model allows users to assess many different packaging systems using a single model. Its input/output interface is designed for users without preexisting knowledge of LCA theory or practice and calculates results based on relatively few input data. The main motivation behind this environmental design tool is to provide relevant information to those individuals who are in the best position to reduce life cycle impacts and costs from TMS's packaging and distribution systems.     

Does the Production of an Airbag Injure more People than the Airbag Saves in Traffic?

Social life cycle assessment (S‐LCA) has been discussed for some years in the LCA community. We raise two points of criticism against current S‐LCA approaches. First, the development of S‐LCA methodology has not, to date, been based on experience with actual case studies. Second, for social impacts to be meaningfully assessed in a life cycle perspective, social indicators need to be unambiguously interpreted in all social contexts along the life cycle. We here discuss an empirically based approach to S‐LCA, illustrated by a case study of an automobile airbag system. The aim of the case study is to compare the injuries and lives lost during the product life cycle of the airbag system (excluding waste handling impacts) with the injuries prevented and lives saved during its use. The indicator used for assessing social impacts in this study is disability‐adjusted life years (DALY). The results from this study indicate that the purpose of an airbag system, which is to save lives and prevent injuries, is justified also in a life cycle perspective.     

Product Environmental Life-Cycle Assessment Using Input-Output Techniques

Life-cycle assessment (LCA) facilitates a systems view in environmental evaluation of products, materials, and processes. Life-cycle assessment attempts to quantify environmental burdens over the entire life-cycle of a product from raw material extraction, manufacturing, and use to ultimate disposal. However, current methods for LCA suffer from problems of subjective boundary definition, inflexibility, high cost, data confidentiality, and aggregation.
This paper proposes alternative models to conduct quick, cost effective, and yet comprehensive life-cycle assessments. The core of the analytical model consists of the 498 sector economic input-output tables for the U.S. economy augmented with various sector-level environmental impact vectors. The environmental impacts covered include global warming, acidification, energy use, non-renewable ores consumption, eutrophication, conventional pollutant emissions and toxic releases to the environment. Alternative models are proposed for environmental assessment of individual products, processes, and life-cycle stages by selective disaggregation of aggregate input-output data or by creation of hypothetical new commodity sectors. To demonstrate the method, a case study comparing the life-cycle environmental performance of steel and plastic automobile fuel tank systems is presented.     

Economic Consequences of Increasing Polymer Content for the U.S. Automobile Recycling Infrastructure

Environmental awareness regarding resource use and emissions over the life cycle of the automobile has heightened the concerns for end-of-life (EOL) vehicle disposal. With increasing use of lighter materials to enhance fuel economythe steel dominated content of automobiles is changing to include a greater fraction of polymers. In light of impending regulations for vehicle disposal, various alternatives for remanufacturing and reuse of components and material disposal are under investigation. For example, if shredder operations are used to reclaim metallic materials, then the extent of disassembly will significantly affect proftability as well as the environment.
Using goal programming, we explore changes to the current US. vehicle recycling infrastructure for their effects on dismantler and shredder proftabilities. To investigate the effect of lightweighting on the profrtabilrty of the recycling infrastructure, two specific vehicle designs are compared: a steel unibody and a polymer-intensive vehicle. Other scenarios examine the outcomes for mandating removal of polymer materials during disassembly and for increasing the disposal cost of scrap polymer to that of hazardous waste. The results indicate that, if properly controlled, the current automobile recycling infrastructure in the United States can remain economically viable while it improves with respect to environmental considerations. Alternatively, implementation of certain policies that reduce profitability could cause disastrous consequences, resulting in the economic collapse of the infrastructure.     

Greenhouse Gas Emissions Payback for Lightweighted Vehicles Using Aluminum and High‐Strength Steel

In this article we consider interactions between life cycle emissions and materials flows associated with lightweighting (LW) automobiles. Both aluminum and high‐strength steel (HSS) lightweighting are considered, with LW ranging from 6% to 23% on the basis of literature references and input from industry experts. We compare the increase in greenhouse gas (GHG) emissions associated with producing lightweight vehicles with the saved emissions during vehicle use. This yields a calculation of how many years of vehicle use are required to offset the added GHG emissions from the production stage. Payback periods for HSS are shorter than for aluminum. Nevertheless, achieving significant LW with HSS comparable to aluminum‐intensive vehicles requires not only material substitution but also the achievement of secondary LW by downsizing of other vehicle components in addition to the vehicle structure. GHG savings for aluminum LW varies strongly with location where the aluminum is produced and whether secondary aluminum can be utilized instead of primary. HSS is less sensitive to these parameters. In principle, payback times for vehicles lightweighted with aluminum can be shortened by closed‐loop recycling of wrought aluminum (i.e., use of secondary wrought aluminum). Over a 15‐year time horizon, however, it is unlikely that this could significantly reduce emissions from the automotive industry, given the challenges involved with enabling a closed‐loop aluminum infrastructure without downcycling automotive body structures.