Effects of Biodiesel Blends on Vehicle Emissions
10/1/2006
Biodiesel is a fuel-blending component produced from vegetable oils, animal fats, or waste grease by reaction with methanol or ethanol to produce methyl or ethyl esters. Engine dynamometer studies reviewed in a 2002 report from EPA show a 2% increase in oxides of nitrogen (NOx) emissinos for B20. This perceived small increase in NOx is leading some state regulatory agencies to consider banning the use of biodiesel. This study was a reassessment of the impact of B20 on NOx emissions. Based on the studies reviewed and new data reported in the present report, there does not appear to be a discrepancy between engine and chassis testing studies for the effect of B20 on NOx emissions. Individual engines may show NOx increasing or decreasing, but on average there appears to be no net effect, or at most a very small effect on the order of +/-0.5%. We have concluded, considering all the data available, that B20 has no net impact on NOx.
Authors: McCormick, R.L.; Williams, A.; Ireland, J.; Brimhall, M.; Hayes, R.R.
Gasification Research Center
9/30/2006
Gas Technology Institute (GTI) is leading an effort to integrate and evaluate syngas cleanup and treatment technologies for syngas from biomass gasification processes. Researchers will screen and evaluate gas cleanup and processing technologies and process monitoring instrumentation for potential implementation in integrated biorefineries based on the thermochemical production of syngas.
Authors: U.S. DOE Biomass Program
King County Metro Transit: Allison Hybrid Electric Transit Bus Laboratory Testing
9/1/2006
The National Renewable Energy Laboratory's ReFUEL facility conducted chassis dynamometer testing of two 60-foot articulated transit buses, one conventional and one hybrid. Both test vehicles were 2004 New Flyer buses powered by Caterpillar C9 8.8L engines, with the hybrid vehicle incorporating a GM-Allison advanced hybrid electric drivetrain. Both vehicles also incorporated an oxidizing diesel particulate filter. The hybrid vehicle demonstrated the greatest improvement in fuel economy in the low speed, heavy stop-and-go driving conditions of the Manhattan (N.Y.)test cycle (74.6%), followed by the Orange County (Calif.) test cycle (50.6%), the Central Business District cycle (48.3%), and the King County (Wash.) Metro test cycle (30.3%). Emission trends were similar to fuel economy improvement trends. The hybrid shoed reductions in NOx emissions over the Manhattan cycle (38.7%), the Orange County cycle (28.6%), the Central Business District cycle (26.6%), and the King County test cycle (17.8%). Vehicle exhaust emissions, fuel consumption, and state of charge of the energy storage system were measured for repeated test conditions. The remainder of this document includes the experimental setup, test procedures, and results from vehicle testing performed at the NREL ReFUEL laboratory.
Authors: Hayes, R.R.; Williams, A.; Ireland, J.; Walkowicz, K.
Plug-In Hybrid Vehicle Analysis - Milestone Report
9/1/2006
NREL's plug-in hybrid electric vehicle (PHEV) analysis activities in FY06 were aimed at objectively assessing PHEV technology, support the larger U.S. DOE PHEV assessment effort, and share technical knowledge with the vehicle research community and vehicle manufacturers. This report includes research papers and presentations developed in FY06 and focuses on fuel economy reporting methods, cost and consumption benefit analysis, real-world performance expectations, and energy management strategies.
Authors: Markel, T.; Brooker, A.; Gonder, J.; O'Keefe, M.; Simpson, A.; Thornton, M.
Notes: To request this document on CD, contact Techical Support Resources at 800-254-6735.
Case Study: Ebus Hybrid Electric Buses and Trolleys
7/1/2006
The Indianapolis Transportation Corp. and Knoxville Area Transit participated in a demonstration of hybrid electric buses and trolleys produced by Ebus, Inc. of Downey, California. This is a case study of performance, costs, and maintenance experience.
Authors: Barnitt, R.
A Guide for Evaluating the Requirements of Ethanol Plants
6/20/2006
During the past decade, interest in the production of biofuels from renewable resources has continued to grow throughout the U.S. Major grain producing states have placed special emphasis on the production of ethanol. The currrent demand for ethanol and the projected increase in the use of these fuels under a national renewable fuels standard continues to stimulate interest in the prospects for the development of new ethanol plants. This publication is designed to assist interested parties during the initial stages of evaluating the potential for the development of a processing facility. Interested parties can consider the requirements and potential impact of an ethanol production facility in a community or region of the state. The value-added aspects of producing a high value product from lower cost raw materials has considerable appeal in agricultural states and areas where reliable supplies of biomass feedstocks exist.
Effect of Biodiesel Blends on Diesel Particulate Filter Performance
6/1/2006
Tests of ultra-low sulfur diesel blended with soy-biodiesel at 5% and 20% were conducted using a 2002 model year Cummins ISB engine (with exhaust gas recirculation) that had been retrofitted with a passively regenerated catalyzed diesel particulate filter (DPF). Results show that on average, the DPF balance point temperature is 45 degrees C. and 112 degrees C lower for B20 blends and neat biodiesel, respectively, than for 2007 certification diesel fuel. Biodiesel causes a measurable increase in regeneration rate at a fixed steady-state condition, even at the 5% blending level. The data showed no significant differences in NOx emissions for these fuels at the steady-state regeneration conditions.
Authors: Williams, A.; McCormick, R.L.; Hayes, R.R.; Ireland, J.; Fang, H.L.
Clean Cities Alternative Fuel Price Report, June 2006
6/1/2006
The Clean Cities Alternative Fuel Price Report is a quarterly report designed to keep you up to date on the prices of alternative fuels and conventional fuels in the U.S. Prices were collected during May and June of 2006.
Designing New Transit Bus Garages to be Fuel Flexible
5/12/2006
The basic differences between the properties of gaseous and liquid fuels influence building design requirements for transit bus garages. Leaks, flammability range, and ignition temperatures must be considered when designing the structure, utilities, ventilation, and safety equipment.
Authors: Adams, R.