Chris Hendrickson

Life cycle greenhouse gas emissions of Marcellus shale gas

This study estimates the life cycle greenhouse gas (GHG) emissions from the production of Marcellus shale natural gas and compares its emissions with national average US natural gas emissions produced in the year 2008, prior to any significant Marcellus shale development. We estimate that the development and completion of a typical Marcellus shale well results in roughly 5500 t of carbon dioxide equivalent emissions or about 1.8 g CO2e/MJ of gas produced, assuming conservative estimates of the production lifetime of a typical well. This represents an 11% increase in GHG emissions relative to average domestic gas (excluding combustion) and a 3% increase relative to the life cycle emissions when combustion is included. The life cycle GHG emissions of Marcellus shale natural gas are estimated to be 63‐75 g CO2e/MJ of gas produced with an average of 68 g CO2e/MJ of gas produced. Marcellus shale natural gas GHG emissions are comparable to those of imported liquefied natural gas. Natural gas from the Marcellus shale has generally lower life cycle GHG emissions than coal for production of electricity in the absence of any effective carbon capture and storage processes, by 20‐50% depending upon plant efficiencies and natural gas emissions variability. There is significant uncertainty in our Marcellus shale GHG emission estimates due to eventual production volumes and variability in flaring, construction and transportation.

The Flexibility of Departure Times for Work Trips

Abstract We examine the flexibility of departure times for the journey to work making use of data gathered in Pittsburgh, Pennsylvania. Measured travel time peaking is pronounced for trips into the Pittsburgh Central Business District, although the variation in travel timeis low for a particular route, mode and departure time. Estimation of a logit model of simultaneous mode and departure time interval choice is reported. Departure time decisions are found to be much more flexible (elastic) than are mode choices. Some implications for dynamic or time dependent transportation system management strategies are considered.

Reverse-Logistics Strategy for Product Take-Back

Product take-back of consumer products is generally expensive, especially reverse logistics. In the take-back program for power tools in Germany, costs exceed revenues for recycling power tools. Systematic analysis of take-back alternatives can make take-back policies more attractive. For example, an alternative take-back system for power tools would combine profitable remanufacturing and unprofitable materials recycling. The profit from remanufacturing could cover the loss from recycling as well as the costs of reverse logistics, allowing the manufacturer a profit. Remanufacturing requires a continuous flow of returned postconsumer products. By buying back end-of-life products, firms could control the flow of returned products. We developed a model that allows us to determine the optimal amount to spend on buy-back and the optimal unit cost of reverse logistics. We can use the latter to select a suitable reverse-logistics system for end-of-life products. We apply our model to the remanufacturing take-back concept for power tools, using empirical data on the current take-back program.

Life Cycle Water Consumption and Wastewater Generation Impacts of a Marcellus Shale Gas Well

This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the economic input–output life cycle assessment (EIO-LCA) method. Life cycle direct and indirect water quality pollution impacts were assessed and compared using the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Wastewater treatment cost was proposed as an additional indicator for water quality pollution impacts from shale gas well wastewater. Four water management scenarios for Marcellus shale well wastewater were assessed: current conditions in Pennsylvania; complete discharge; direct reuse and desalination; and complete desalination. The results show that under the current conditions, an average Marcellus shale gas well consumes 20 000 m3 (with a range from 6700 to 33 000 m3) of freshwater per well over its life cycle excluding final gas utilization, with 65% direct water consumption at the well site and 35% indirect water consumption across the supply chain production. If all flowback and produced water is released into the environment without treatment, direct wastewater from a Marcellus shale gas well is estimated to have 300–3000 kg N-eq eutrophication potential, 900–23 000 kg 2,4D-eq freshwater ecotoxicity potential, 0–370 kg benzene-eq carcinogenic potential, and 2800–71 000 MT toluene-eq noncarcinogenic potential. The potential toxicity of the chemicals in the wastewater from the well site exceeds those associated with supply chain production, except for carcinogenic effects. If all the Marcellus shale well wastewater is treated to surface discharge standards by desalination,

Optimal Plug-In Hybrid Electric Vehicle Design and Allocation for Minimum Life Cycle Cost, Petroleum Consumption, and Greenhouse Gas Emissions

59 000–270 000 per well would be required. The life cycle study results indicate that when gas end use is not considered hydraulic fracturing is the largest contributor to the life cycle water impacts of a Marcellus shale gas well.

Comparison of Environmental Implications of Asphalt and Steel-Reinforced Concrete Pavements

Plug-in hybrid electric vehicle (PHEV) technology has the potential to reduce operating cost, greenhouse gas (GHG) emissions, and petroleum consumption in the transportation sector. However, the net effects of PHEVs depend critically on vehicle design, battery technology, and charging frequency. To examine these implications, we develop an optimization model integrating vehicle physics simulation, battery degradation data, and U.S. driving data. The model identifies optimal vehicle designs and allocation of vehicles to drivers for minimum net life cycle cost, GHG emissions, and petroleum consumption under a range of scenarios. We compare conventional and hybrid electric vehicles (HEVs) to PHEVs with equivalent size and performance (similar to a Toyota Prius) under urban driving conditions. We find that while PHEVs with large battery packs minimize petroleum consumption, a mix of PHEVs with packs sized for 25– 50 miles of electric travel under the average U.S. grid mix (or 35– 60 miles under decarbonized grid scenarios) produces the greatest reduction in life cycle GHG emissions. Life cycle cost and GHG emissions are minimized using high battery swing and replacing batteries as needed, rather than designing underutilized capacity into the vehicle with corresponding production, weight, and cost implications. At 2008 average U.S. energy prices, Li-ion battery pack costs must fall below

Energy implications of online book retailing in the United States and Japan

590/kW h at a 5% discount rate or below

Sensor-based data recording of use conditions for product takeback

410/kW h at a 10% rate for PHEVs to be cost competitive with HEVs. Carbon allowance prices offer little leverage for improving cost competitiveness of PHEVs. PHEV life cycle costs must fall to within a few percent of HEVs in order to offer a cost-effective approach to GHG reduction. DOI: 10.1115/1.4002194

Regional Variability and Uncertainty of Electric Vehicle Life Cycle CO2 Emissions across the United States

The public, industry, and governments have become increasingly interested in green design and sustainable development. Construction activities affect the environment significantly, so environmental issues should be considered seriously. Thousands of miles of roads are paved every year with asphalt and steel-reinforced concrete. What are the environmental effects of the two materials? If asphalt has been used overwhelmingly over concrete, is it a better choice for sustainable development? We present results of a life cycle inventory analysis of the two materials based on publicly available data. We find that for the initial construction of equivalent pavement designs, asphalt appears to have higher energy input, lower ore and fertilizer input requirements, and lower toxic emissions, but it has higher associated hazardous waste generation and management than steel-reinforced concrete. When accounting for the uncertainty in the data and when annualizing environmental effects based on assumed average service lives of the two pavement types, the resource input requirements and the environmental outputs are roughly comparable for the two materials. However, asphalt pavements have been recycled in larger quantities than concrete pavements, with consequent resource savings and avoided pollution, which suggests that asphalt may be a better choice from a sustainable development viewpoint. Of course, special functional requirements or economics may dictate the use of one material over the other in particular applications regardless of the overall environmental effects.

Environmental and Economic Effects of E-Commerce: A Case Study of Book Publishing and Retail Logistics

Abstract The advent of the Internet and e-commerce has brought a new way of marketing and selling many products, including books. The system-wide impacts of this shift in retail methods on cost, energy, and the environment are still unclear. While reductions in inventories and returns provide significant savings, some of the major concerns of e-commerce business models are the energy and packaging materials used by the logistics networks for product fulfillment and delivery. In this paper, we analyze the different logistics networks and assess the energy and cost impacts of different delivery systems in the United States and Japan. In Japan, the results suggest a crossover in energy use according to population density. In the United States, the crossover also exists, based on delivery method and distance to local bookstores. In neither case, however, are the potential spillover energy benefits from e-commerce-based methods considered. The results show notable differences for the two distribution methods, and suggest areas where further energy improvements may be possible.