2007-2008 Steinbrenner Doctoral Fellows

Anny Huang (Engineering and Public Policy)

Title: Life Cycle Energy and Environmental Impacts of Extended Product Responsibility Policy

Advisor: H. Scott Matthews

Project Description: Increased production of goods in modern times has improved people’s quality of life and enabled economic growth. However, it has also led to significant increases in resource extraction, environmental degradation, and waste output. Traditionally, municipalities are given the responsibility to manage the increasing amount of waste but have no control of waste generation. In the recent decade, several countries in Europe and Asia have transferred the responsibility of waste management to producers by implementing extended producer responsibility (EPR) policies—policies that require producers to be financially or physically responsible for their products after their useful life. EPR policies give producers strong incentives to redesign their products with more effective end-of-life management (EOLM) in mind. It often results in producers having to “take back” products from customers, requiring the design of reverse logistics systems to handle the large volumes of product. Reverse transportation and recycling of products are two important life cycle phases to consider when comparing EPR policy options with traditional EOLM of waste.

Using the Economic Input-Output Life Cycle Assessment (EIO-LCA) methodology, the authors conducted an economy-wide assessment of the potential impacts of EPR policy scenarios. Using data from the purchaser price input-output model compiled by the U.S. Bureau of Economic Analysis, which provide estimates of transportation expenses resulting from delivery of goods from producers to consumers, life cycle environmental impacts of transporting goods between producers and consumers are calculated and compared to the environmental “credits” of recycling estimated using a modified EIO-LCA model. It is found that although reverse logistics transportation of product take-back contributes to certain environmental burdens in the economy, the energy consumed during delivery of most goods is relatively small compared to the energy embodied in the goods during the manufacturing phase. Improved recycling and resource recovery practices can potentially reduce the total energy consumption of industries in the economy. This presentation provides an overview of the research findings and policy implications.

Heather Wakeley (Civil and Environmental Engineering)

Title: Alternative Transportation Fuels: Infrastructure Requirements and Environmental Impacts for Hydrogen and Ethanol

Advisor: Chris Hendrickson

Project Description: Ethanol and hydrogen are receiving considerable attention as alternative fuels for transportation. They could reduce greenhouse gas emissions and promote US energy independence. The increasing cost of petroleum also makes the economics of alternative fuels more attractive. At 2006 gasoline prices, ethanol and hydrogen would have comparable or lower fuel costs. In this paper, we analyze distribution options (of pipeline, rail and truck) for alternative fuels using the State of Iowa as a test case. By switching to E85 in Iowa, local ethanol production from cellulosic biomass and corn could replace 82% of its gasoline use. Hydrogen derived from steam methane reforming at 7 facilities, capturing economies of scale, located nascent to population centers throughout Iowa could replace all gasoline usage in the state. We find that none of the scenarios we analyze are dominant with regard to all of the dimensions of user cost, capital costs, environmental costs and safety risks. There are strong economies of scale in distribution paths, so that a major shift to alternative fuels is needed to achieve the most cost effective distribution methods. There is considerable uncertainty in our cost estimates, particularly for the production costs of ethanol from cellulosic biomass, feedstock costs for hydrogen production and the future price of petroleum.

Yan Xu (Civil and Environmental Engineering)

Title: Development of Novel Contaminant Source Tracking with Molecular Microbiology

Advisor: Jeanne VanBriesen

Project Description: Environmental restoration of watersheds contaminated with pathogenic microorganisms initially requires identification of the physical sources of contamination. Pathogens can be released to the environment from (1) improper handling of human waste (e.g., failing on lot septic systems, overflowing sanitary and combined sewer systems), (2) agricultural practices that allow domestic animals to traverse freshwater systems or that discharge wastes from confined feed lots, and (3) natural sources like wild animals (e.g., deer, raccoon, etc.). Identification of possible sources in a watershed is a relatively easy process; but determination of which possible source is contributing a significant load that can be reduced through better engineering or management practices is much more difficult.

In the past several years, a number of chemical and microbiological "source tracking" methods have been developed. Most of these enable the identification of the host organism source for a given pathogen found in a system. Unfortunately, they do not enable identification of the physical source of waste. So, while it is possible in some systems to identify that the pathogen loading is from human beings more than from deer, it is not possible to determine which sewer overflow location or which area of septic systems is the critical failure that requires remediation. Further, all current source tracking methods require a library of information to be generated from within the study watershed; these libraries are not generalizable to other watershed.