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Clean Cities Niche Market Overview: Refuse Haulers
9/1/2011
Many niche market fleets, which operate specially designed vehicles that serve very specific functions, are ideal for the adoption of alternative fuels and advanced vehicle technologies. One prime example is the refuse hauler sector, whose 136,000 trucks average only 2.8 miles per gallon, using more than 1.2 billion gallons of fuel annually in the United States. This sector could substantially decrease its petroleum consumption through the use of alternative fuel or advanced technology vehicles. Before adopting these technologies, a refuse hauler fleet should consider both the technologies' benefits and the fleet's individual needs.
Authors: Shea, S.
A Waste-to-Wheel Analysis of Anaerobic-Digestion-Based RNG Pathways with the GREET Model
9/1/2011
This study captures results from a life cycle analysis that was conducted to quantify the greenhouse gas (GHG) impact of converting methane from animal manure into renewable natural gas (RNG) and utilizing the gas in vehicles. Several manure-based RNG pathways were characterized in the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model, and their fuel-cycle energy use and GHG emissions were compared to petroleum-based pathways as well as to conventional fossil natural gas pathways.
Authors: Han, J.; Mintz, M.; Wang, M.
Clean Cities Annual Metrics Report 2009 (Revised)
8/10/2011
Each year, the U.S. Department of Energy (DOE) asks Clean Cities coordinators to submit an annual report of their activities and accomplishments for the previous calendar year. Data and information are submitted to an online database that is maintained as part of the Alternative Fuels and Advanced Vehicles Data Center (AFDC) at the National Renewable Energy Laboratory (NREL). Coordinators submit a range of data that characterizes the membership, funding, projects, and activities of their coalitions. They also submit data about sales of alternative fuels, deployment of alternative fuel vehicles (AFVs), hybrid electric vehicles (HEVs), idle reduction initiatives, fuel economy activities, and programs to reduce vehicle miles driven. NREL analyzes the data and translates them into gasoline reduction impacts, which are summarized in this report.
Authors: Johnson, C.
Clean Alternative Fuel Vehicle and Engine Conversions; Final Rule
4/8/2011
EPA is streamlining the process by which manufacturers of clean alternative fuel conversion systems may demonstrate compliance with vehicle and engine emissions requirements. Specifically, EPA is revising the regulatory criteria for gaining an exemption from the Clean Air Act prohibition against tamperingfor the conversion of vehicles and engines to operate on a clean alternativefuel. This final rule creates additional compliance options beyond certification that protect manufacturers of clean alternative fuel conversion systems against a tampering violation, depending on the age of the vehicle orengine to be converted. The new options alleviate some economic and proceduralimpediments to clean alternative fuel conversions while maintainingenvironmental safeguards to ensure that acceptable emission levels from converted vehicles are sustained.
Project Results: Evaluating FedEx Express Hybrid-Electric Delivery Trucks
4/1/2011
The National Renewable Energy Laboratory's (NREL's) Fleet Test and Evaluation Team evaluated the 12-month, in-service performance of three Class 4 gasoline hybrid-electric delivery trucks and three comparable conventional diesel trucks operated by FedEx Express in Southern California. In addition, the tailpipe emissions and fuel economy of one of the gasoline hybrid-electric vehicles (gHEVs) and one diesel truck were tested on a chassis dynamometer. The gHEVs were equipped with a parallel hybrid system manufactured by Azure Dynamics, including a 100-kW alternating current induction motor, regenerative braking, and a 2.45-kWh nickel metal hydride battery pack. This fact sheet summarizes the results of the evaluation of the gHEVs.
Impact of Biodiesel Impurities on the Performance and Durability of DOC, DPF and SCR Technologies: Preprint.
4/1/2011
Presented at the SAE 2011 World Congress, 12-14 April 2011, Detroit, Michigan.
An accelerated durability test method determined the potential impact of biodiesel ash impurities, including engine testing with multiple diesel particulate filter substrate types, as well as diesel oxidation catalyst and selective catalyst reduction catalysts. The results showed no significant degradation in the thermo-mechanical properties of a DPF after exposure to 150,000-mile equivalent biodiesel ash and thermal aging. However, exposure to 435,000-mile equivalent aging resulted in a 69% decrease in thermal shock resistance. A decrease in DOC activity was seen after exposure to 150,000-mile equivalent aging, resulting in higher hydrocarbon slip and a reduction in NO2 formation. The SCR catalyst experienced a slight loss in activity after exposure to 435,000-mile equivalent aging. The SCR catalyst, placed downstream of the DPF and exposed to B20 exhaust suffered a 5% reduction in overall NOx conversion activity over the HDDT test cycle. It is estimated that the additional ash from 150,000 miles of biodiesel use would also result in a moderate increases in exhaust backpressure for a DPF. The results of this study suggest that long-term operation with B20 at the current specification limits for alkali and alkaline earth metal impurities will adversely impact the performance of DOC, DPF and SCR systems.
Authors: Williams, A.; McCormick, R.; Luecke, J.; Brezny, R.; Geisselmann, A.; Voss, K.; Hallstrom, K.; Leustek, M.; Parsons, J.; Abi-Akar, H.
Blueprint for a Secure Energy Future
3/30/2011
The Blueprint for a Secure Energy Future outlines a three-part strategy: 1) Develop and secure America's energy supplies; 2) provide consumers with more choices of alternative fuels and advanced and fuel-efficient vehicles, alternative means of transportation; and 3) innovate our way to a clean energy future by creating markets for innovative clean technologies that are ready to deploy and by funding cutting edge research to produce the next generation of technologies.
Project Startup: Evaluating Coca-Cola's Class 8 Hybrid-Electric Delivery Trucks
3/1/2011
Although the largest trucks?Class 8, with a gross vehicle weight rating (GVWR) above 33,000 lb?make up only 1% of the U.S. highway vehicle fleet, they are responsible for almost 20% of highway petroleum consumption. Improving theefficiency of Class 8 trucks through strategies such as alternative fuels and hybridization is a high-impact way to reduce petroleum consumption and associated emissions. The National Renewable Energy Laboratory's Fleet Test and Evaluation Team is evaluating the 12-month, in-service performance of five Class 8 diesel hybrid-electric delivery trucks and five comparable conventional diesel trucks operated by Coca-Cola Refreshments in Miami/South Dade County, Florida. In addition, the tailpipe emissions and fuel economies of one hybrid and one diesel truck have been evaluated on a chassis dynamometer at NREL's Renewable Fuels and Lubricants (ReFUEL) Laboratory.
Hydrogen Fuel Cell Electric Vehicles
2/1/2011
Hydrogen fuel cell electric vehicles can play an important role in the portfolio of sustainable transportation fuel options, reduce dependence on imported oil and enable global economic leadership for America.
FedEx Express Gasoline Hybrid Electric Delivery Truck Evaluation: 12-Month Report
1/1/2011
This document presents the final results of a technology evaluation of gasoline hybrid electric parcel delivery trucks operated by FedEx Express in and around Los Angeles, California. FedEx Express is a large commercial fleet that operates more than 30,000 motorized vehicles and has hybrid electric (diesel and gasoline) vehicles currently in service. FedEx Express has deployed 20 gasoline hybrid electric vehicles (gHEVs) on parcel delivery routes in the Sacramento and Los Angeles areas. These gHEVs (Figure 1) are built upon a Ford E-450 strip chassis, and each vehicle is powered by a Ford 5.4L gasoline engine and Azure Dynamics, Inc. (AZD) Balance Hybrid System. Additional vehicle information is discussed in subsequent sections, while the specifics of the hybrid system evaluated are presented in Table 1. FedEx Express was the domestic launch customer for the AZD Balance Hybrid electric product.
Authors: Barnitt, R.
Renewable Fuel Standard: Potential Economic and Environmental Effects of U.S. Biofuel Policy
1/1/2011
Renewable Fuel Standard evaluates the economic and environmental consequences of increasing biofuels production as a result of Renewable Fuels Standard, as amended by EISA (RFS2). The report describes biofuels produced in 2010 and those projected to be produced and consumed by 2022, reviews model projections and other estimates of the relative impact on the prices of land, and discusses the potential environmental harm and benefits of biofuels production and the barriers to achieving the RFS2 consumption mandate.
Notes: Book available for purchase from The National Academies Press
Effect of Saturated Monoglyceride Polymorphism on Low-Temperature Performance of Biodiesel
1/1/2011
Journal article in Energy and Fuels. Vol. 25(1) 20 January 2011, pp. 398-405.
To investigate precipitates above the cloud point (CP) in biodiesel, three saturated monoglycerides (SMGs), monomyristin, monopalmitin, and monostearin, were spiked into distilled soy and animal fat-derived B100. It was shown that above a threshold or eutectic concentration the SMGs significantly raise the CP of B100. A comparison to published data suggests that commercial B100 has SMG content in the same range as the eutectic point. SMGs have an even greater impact on the final melting temperature (FMT, as measured when the sample is heated) at concentrations above the eutectic point. These results were verified and visualized using a controlled temperature stage microscope. It was shown that the FMT was highly dependent on the rate of heating. It is hypothesized that a lower melting point crystalline form of the SMG forms upon rapid cooling and then transforms into a more stable, higher melting point crystalline form when slowly heated or held at constant temperature. The CP and FMT results of this study were compared to an ideal solution thermodynamic model. The model was able to provide reasonable prediction of the eutectic point but was less successful at predicting CP and FMT above the eutectic.
Authors: Chupka, G. M.; Yanowitz, J.; Chiu, G.; Alleman, T. L.; McCormick, R. L.
To Idle or Not to Idle: That is the Question
11/1/2010
Should I idle my car to warm it up before I drive? Should I shut the engine off while waiting to pick up a passenger or for a train to go by? Is it better to pick up food at a drive-through or to park and go into the restaurant? These are common questions that people ask when they want to know more about how to drive "green." There are conflicting answers in the literature, which has led to confusion. This poster presents the results of measurements performed on both diesel and gasoline passenger vehicles at Argonne National Laboratory. The answers are found to depend on vehicle type, ambient temperature, time, local laws, and what criteria are used to define "green."
