Search Results

The “Truck in the Park” project was a jointly funded research project which demonstrated the benefits of the use of biodiesel in a tourism related industry. The National Park Service (NPS) operated a truck in Yellowstone National Park (YNP) for 149,408 km (92,838 miles) on 100% biodiesel fuel produced by the University of Idaho. Participants in this project included Montana Department of Environmental Quality, Wyoming Department of Commerce, NPS, Department of Energy's Regional Biomass Energy Program, Koch Agri-Services, Dodge Truck, Cummins Engine Company, J.R. Simplot, Western States Caterpillar, University of California at Davis, and the University of Idaho. This summary report details the fuel production, engine performance, durability, and engine emissions tests performed on the test vehicle. The test vehicle was a 1995 Dodge 2500 four-wheel-drive pickup with a Cummins B 5.9 liter turbocharged, direct injected, diesel engine.

This paper describes two independent studies on γ-alumina as a plasma-activated catalyst. γ-alumina (2.5 - 4.3 wt%) was coated onto the surface of mesoporous silica to determine the importance of aluminum surface coordination on NOx conversion in conjunction with nonthermal plasma. Results indicate that the presence of 5- and 6- fold aluminum coordination sites in γ-alumina could be a significant factor in the NOx reduction process. A second study examined the effect of changing the reducing agent on NOx conversion. Several hydrocarbons were examined including propene, propane, isooctane, methanol, and acetaldehyde. It is demonstrated that methanol was the most effective reducing agent of those tested for a plasma-facilitated reaction over γ-alumina.

It is estimated that operating continuously on a B20 fuel containing the current allowable ASTM specification limits for metal impurities in biodiesel could result in a doubling of ash exposure relative to lube-oil-derived ash. The purpose of this study was to determine if a fuel containing metals at the ASTM limits could cause adverse impacts on the performance and durability of diesel emission control systems. An accelerated durability test method was developed to determine the potential impact of these biodiesel impurities. The test program included engine testing with multiple DPF substrate types as well as DOC and SCR catalysts. The results showed no significant degradation in the thermo-mechanical properties of cordierite, aluminum titanate, or silicon carbide DPFs after exposure to 150,000 mile equivalent biodiesel ash and thermal aging. However, exposure of a cordierite DPF to 435,000 mile equivalent aging resulted in a 69% decrease in the thermal shock resistance parameter.

This paper features an application study on the impact of different blend levels of commercially-supplied biodiesel on engine and aftertreatment systems' durability and reliability as well as the impact on owning and operating factors: service intervals and fuel economy. The study was conducted on a bus application with a 2007 on highway emissions equipped engine running biodiesel blends of B5, B20, and B99 for a total period approaching 4500 hours. Biodiesel of waste cooking grease feedstock was used for the majority of the testing, including B5 and B20 blends. Biodiesel of soybean feedstock was used for testing on B99 blend. No negative impacts on engine and aftertreatment performance and durability or indication of future potential issues were found when using B5 and B20. For B99 measurable impacts on engine and aftertreatment performance and owning and operating cost were observed.

Natural gas quality, in terms of the volume fraction of higher hydrocarbons, strongly affects the auto-ignition characteristics of the air-fuel mixture, the engine performance and its controllability. The influence of natural gas composition on engine operation has been investigated both experimentally and through chemical kinetic based cycle simulation. A range of two component gas mixtures has been tested with methane as the base fuel. The equivalence ratio (0.3), the compression ratio (19.8), and the engine speed (1000 rpm) were held constant in order to isolate the impact of fuel autoignition chemistry. For each fuel mixture, the start of combustion was phased near top dead center (TDC) and then the inlet mixture temperature was reduced. These experimental results have been utilized as a source of data for the validation of a chemical kinetic based full-cycle simulation.

Previous research using catalytic igniters and ethanol water fueled mixtures has shown potential for lowering CO and NOx emissions while increasing engine efficiency over conventional engine configurations. Catalytic ignition systems allow combustion initiation over a much wider range of stoichiometry and water composition than traditional spark ignition systems. The platform explored in this research is a transit van converted to operate on either gasoline or ethanol water fuel mixtures. Special attention was devoted to improve cold starting and installing additional on board sensors and equipment for future testing. System features include integration of a wide band oxygen sensor, state-of-the-art engine management system, exhaust gas temperature sampling using platinum thin film resistive temperature devices and variable voltage control of catalytic igniters using DC-DC boost converters.

Two on-road diesel pickups were operated on a mixture of 20 percent Biodiesel and 80 percent diesel for 80,000 kilometers (km). The engines were unmodified, but modifications were made to the vehicles for the convenience of the test. Fuel mixing was done on-board to extend the driving range to over 5,000 km between Biodiesel fill ups. Chassis dynamometer testing, injector coking, engine compression, injector valve opening pressures, and engine oil analyses were done at regularly scheduled intervals to monitor the engine performance parameters. RME produced 5 percent less power than D2, while 20RME and 20RAW produced one percent less power than D2. Smoke density was reduced 39 percent with RME, while 20RME increased 18 percent, and 20RAW decreased smoke density by 3.1 times that of D2.

The goal of this research is to determine the feasibility of a catalytic compression-ignition engine running on aqueous ethanol fuel. A naturally aspirated, three-cylinder, direct-injection diesel engine manufactured by Yanmar has been modified to operate as a homogeneous-charge, compression-ignition engine. This involved removing the fuel injectors, replacing them with catalytic elements located inside a small pre-chamber, and installing a pulse width modulated fuel injection system. The fuel is 35% water and 65% ethanol by volume. The catalytic igniters allow the engine to operate continuously at various load levels corresponding to a broad range of air/fuel ratios. To adjust ignition timing and monitor in-cylinder combustion, the engine has been instrumented with a piezoelectric pressure transducer and a crankshaft encoder. Pressure traces are quite repeatable from cycle to cycle and resemble combustion patterns in typical Otto cycle engines.

In July 1997, the Pacific Northwest and Alaska Regional Bioenergy Program, in cooperation with several industrial and institutional partners initiated a long-haul 322,000 km (200,000 mile) operational demonstration using a biodiesel and diesel fuel blend in a 324 kW (435 HP), Caterpillar 3406E Engine, and a Kenworth Class 8 heavy duty truck. This project was designed to: develop definitive biodiesel performance information, collect emissions data for both regulated and non-regulated compounds including mutagenic activity, and collect heavy-duty operational engine performance and durability information. To assess long-term engine durability and wear; including injector, valve and port deposit formations; the engine was dismantled for inspection and evaluation at the conclusion of the demonstration. The fuel used was a 50% blend of biodiesel produced from used cooking oil (hydrogenated soy ethyl ester) and 50% 2-D petroleum diesel.