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The goals of this research are to understand the regeneration process in ceramic (Cordierite) monolith traps using a copper fuel additive and to investigate the various conditions that lead to trap regeneration failure. The copper additive lowers the trap regeneration temperature from approximately 500 °C to 375 °C and decreases the time necessary for regeneration. Because of these characteristics, it is important to understand the effect of the additive on regeneration when excessive particulate matter accumulation occurs in the trap. The effects of particulate mass loading on regeneration temperatures and regeneration time were studied for both the controlled (engine operated at full load rated speed) and uncontrolled (trap regeneration initiated at full load rated speed after which the engine was cut to idle) conditions. The trap peak temperatures were higher for the uncontrolled than the controlled regeneration.

The purpose of this study was to investigate the pressure drop and regeneration characteristics of a silicon carbide (SiC) wall-flow diesel particulate filter. The performance of a 25 μm mean pore size SiC dual trap system (DTS) consisting of two 12 liter traps connected in parallel in conjunction with a copper (Cu) fuel additive was evaluated. A comparison between the 25 μm DTS and a 15 μm DTS was performed, in order to show the effect of trap material mean pore size on trap loading and regeneration behavior. A 1988 Cummins LTA 10-300 diesel engine was used to evaluate the performance of the 15 and 25 μm DTS. A mathematical model was developed to better understand the thermal and catalytic oxidation of the particulate matter. For all the trap steady-state loading tests, the engine was run at EPA mode 11 for 10 hours. Raw exhaust samples were taken upstream and downstream of the trap system in order to determine the DTS filtration efficiency.

Active regeneration experiments were carried out on a production 2007 Cummins 8.9L ISL engine and associated diesel oxidation catalyst (DOC) and catalyzed particulate filter (CPF) aftertreatment system. The effects of SME biodiesel blends were investigated to determine the particulate matter (PM) oxidation reaction rates for active regeneration. The experimental data from this study will also be used to calibrate the MTU-1D CPF model [1]. The experiments covered a range of CPF inlet temperatures using ULSD, B10, and B20 blends of biodiesel. The majority of the tests were performed at a CPF PM loading of 2.2 g/L with in-cylinder dosing, although 4.1 g/L and a post-turbo dosing injector were also investigated. The PM reaction rate was shown to increase with increasing percent biodiesel in the test fuel as well as increasing CPF temperature.

An experimental and computational study was performed to evaluate the performance of the CRT™ technology with an off-highway engine with a cooled low pressure loop EGR system. The MTU-Filter 1D DPF code predicts the particulate mass evolution (deposition and oxidation) in a diesel particulate filter (DPF) during simultaneous loading and during thermal and NO2-assisted regeneration conditions. It also predicts the pressure drop across the DPF, the flow and temperature fields, the solid filtration efficiency and the particle number distribution downstream of the DPF. A DOC model was also used to predict the NO2 upstream of the DPF. The DPF model was calibrated to experimental data at temperatures from 230°C to 550°C, and volumetric flow rates from 9 to 39 actual m3/min.

A 1-D 2-layer model developed previously at MTU was used in this research to predict the pressure drop, filtration characteristics and various properties of the particulate filter and the particulate deposit layer. The model was calibrated and validated for this CPF with data obtained from steady state experiments conducted using a 1995 Cummins M11-330E heavy-duty diesel engine with manual EGR and using ULSF. The CPF used is a NGK filter having a cordierite substrate with NEX catalyst type formulation (54% porosity, 15.0 μm mean pore diameter and 50 gms/ft3 Pt). The filter was catalyzed using a wash coat process. The model was used to predict the pressure drop, particulate mass retained inside the CPF, particulate mass filtration efficiency and concentration downstream of the CPF with agreement between the experimental and simulated data.

A 1-D 2-layer model developed previously at MTU was used in this research to predict the pressure drop, filtration characteristics and various properties of the particulate filter and the particulate deposit layer. The model was used along with dilute emission data to characterize two catalyzed particulate filters (CPFs) having different catalyst loading and catalyst application processes. The model was calibrated and validated with data obtained from steady state experiments conducted using a 1995 Cummins M11-330E heavy-duty diesel engine with manual EGR with different fuels for the two different CPFs. The two different catalyzed particulate filters were CPF III (5 gms/ft3 Pt) and CPF V (50 gms/ft3 Pt). Both the CPFs had cordierite substrates with CPF III and CPF V had MEX and NEX catalyst type formulation respectively. The CPF III filter was catalyzed using a solution-impregnated process while the CPF V filter was catalyzed using a wash coat process.

Formation of pollutants from diesel combustion and methods for their control have been reviewed. Of these methods, fuel injection rate and timing were selected for a parametric study relative to total particulate, soluble organic fraction (SOF), sulfates, solids and NO and NO2 emissions from a heavy-duty, turbocharged, after-cooled, direct-injection (DI) diesel. Chemical analyses of the SOF were performed at selected engine conditions to determine the effects of injection rate and timing on each of the eight chemical subfractions comprising the SOF. Biological character of the SOF was determined using the Ames Salmonella/microsome bioassay.

The effect of fuel changes on diesel oxidation catalyst performance was studied by comparing the physical, chemical and biological character of the particulate emissions using three different fuels. Baseline (uncatalyzed) emissions were also compared for these same fuels. The fuels used for this study were: a typical No. 2 fuel, a No. 1 fuel, and a shale oil-derived diesel fuel. Comparisons of NOX, NO, NO2, HC and particulate mass emissions using each fuel were made using selected modes from the EPA 13 mode cycle. Changes in the chemical and biological character of the soluble organic fraction (SOF) were also studied. Fuel properties, most notably fuel sulfur content, were found to affect the performance of the oxidation catalyst used. Fuel sulfur content should be kept as low as possible if catalytic converters are used on diesel powered equipment.

This is the fourth in a series of tests conducted as a Coordinating Research Council cooperative program to evaluate the measurement methods used to analyze diesel exhaust gas constituents. A multi-cylinder engine was circulated to 15 participants who measured emissions at three engine conditions. All 15 participants measured nitric oxide and carbon monoxide with several laboratories measuring nitric oxide by both NDIR (Non-Dispersive Infrared) and CHEMI (Chemiluminescence). Some participants also measured carbon dioxide, nitrogen dioxide, oxygen, and unknown span gases. The test results are compared with the Phase III cooperative tests which involved simultaneous measurement of emissions by participants. The precision of the results was poorer in Phase IV than Phase III.

The CRC-APRAC CAPI-1-64 Odor Panel was formed in 1973 to assess an instrumental measurement system for diesel exhaust odor (DOAS) developed under CRC-APRAC CAPE-7-68 by Arthur D. Little, Inc. Four cooperative studies were conducted by nine participating laboratories using common samples. The objectives of these studies were to define the DOAS system variables and to validate and improve the sampling and collection procedures. A fifth study, serving as a review of each analysis step, showed that analysis of common derived odorant samples could be conducted within acceptable limits by the participating laboratories. Three in-house sampling system design and operating parameter studies were conducted simultaneously with the cooperative work. The combined findings from the in-house and cooperative studies led to a tentative recommended procedure for measuring diesel exhaust odor.

A cooperative test program was conducted by the CRC-APRAC CAPI-1-64 Composition of Diesel Exhaust Program Group to evaluate the technical aspects of a proposed EPA recommended Heavy Duty Diesel Emission Measurement and Test Procedure. The proposed changes affected the sampling configurations and the types of instruments used. Six participants studied the effects of a number of variables on the proposed changes and evaluated some alternative systems that included both CHEMI and NDIR instruments. The tests were conducted at one site using a multi-cylinder engine operating on the 13-Mode Cycle. Equivalency of systems was demonstrated and the best performance was obtained with a special NDIR system.

The infrared radiation method of compression and end-gas temperature measurement was applied to the problem of measuring gas temperatures up to the time of knock. Pressure data were taken for each run on a CFR engine with mixtures of isooctane and n-heptane under both knocking and nonknocking conditions. Main engine parameters studied were the intake pressure, intake temperature, and engine speed. The rate and extent of chemical energy release were calculated from the temperature and pressure histories using an energy balance. The computed rates of chemical energy release were correlated to a chain-type kinetic model

The prediction of particulate concentrations in dlesel exhaust diluted in a dilution tunnel has been achieved using a computer model. The particulate collection filter temperature, soluble organic fraction (SOF) and solids fraction (SOL) of diesel particulate matter were predicted based on exhaust system and dilution tunnel variables that could be measured on a real-time basis. The SOF was assumed to be formed by adsorption of gaseous hydrocarbons onto the solids fraction. The accuracy of the model was determined by comparison to experimentally measured values. The model was able to predict SOF concentrations within 35%, filter temperatures within 3°G, and particulate (SOF + SOL) concentrations within 25% of measured values. A parametric study was conducted using the developed model; and improved test procedures, dilution tunnel dimensions, and federal testing guidelines were suggested.

Physical, chemical, and biological characterization data for the particulate emissions from a Caterpillar 3208 diesel engine with and without Corning porous ceramic particulate traps are presented. Measurements made at EPA modes 3,4,5,9,lO and 11 include total hydrocarbon, oxides of nitrogen and total particulate matter emissions including the solid fraction (SOL), soluble organic fraction (SOF) and sulfate fraction (SO4), Chemical character was defined by fractionation of the SOF while biological character was defined by analysis of Ames Salmonella/ microsome bioassay data. The trap produced a wide range of total particulate reduction efficiencies (0-97%) depending on the character of the particulate. The chemical character of the SOF was significantly changed through the trap as was the biological character. The mutagenic specific activity of the SOF was generally increased through the trap but this was offset by a decrease in SOF mass emissions.

Analytical ferrography was used as a wear measurement tool while implimenting a procedure to calculate the wear particle generation rate and filter efficiency during laboratory diesel engine testing. The engine testing methodology with quantitative ferrography proved to be a sensitive wear measurement technique in detecting a reduction in the wear particle generation rate for a better anti-wear (API SF/CD) oil from that of a baseline API SD/CD oil. Ferrography and spectroscopy were useful as diagnostic tools for the detection and correction of the unexpected circulation of copper contaminant in the lubrication system. A journal bearing failure was detected with qualitative ferrography and verified with an engine teardown while spectroscopy did not detect the bearing failure.

A study has been made of piston ring wear and total engine wear using literature data and new experimental results. The main purpose of the study was to establish the effects of oil and coolant temperatures on engine wear. Wear trends that were found in the early 1960's may not be valid any longer because of the development of higher BMEP turbocharged diesel engines, better metallurgical wear surfaces and improved lube oil properties. New data are presented for the purpose of describing present wear trends. A direct-injection, 4-cycle, turbocharged diesel engine was used for the wear tests. The radioactive tracer technique was used to measure the top piston ring chrome face wear. Atomic emission spectroscopy was employed to determine the concentration of wear metals in the oil to determine total engine wear based on iron and lead. The data were analyzed and compared to the results found in the literature from previous investigators.

The effect of the use of a manganese-copper fuel additive with a Corning EX-47 particulate trap on heavy-duty diesel emissions has been investigated; reductions in total particulate matter (70%), sulfates (65%), and the soluble organic fraction (SOF) (62%) were measured in the diluted (15:1) exhaust and solids were reduced by 94% as measured in the raw exhaust. The use of the additive plus the trap had the same effect on gaseous emissions (hydrocarbons and oxides of nitrogen) as did the trap alone. The use of the additive without the trap had no effect on measured gaseous emissions, although sulfate increased by 20%. Approximately 50% of the metals added to the fuel were calculated to be retained in the engine system. The metals emitted by the engine were collected very efficiently (>97%) by the trap even during regeneration, which occured 180°C lower when the additive was used.

A study of the Corning ceramic diesel particulate trap was conducted to investigate the trap's overall effect on diesel particulate fractions (soluble organic fraction. SOF; solid fraction, SOL; and sulfate fraction. SO4) under four different engine loads at 1680 rpm. The trap was found to filter the SOL fraction most efficiently with the SOF and SO4 fraction following in respective order. The filter efficiency of all fractions increased with increasing engine load. Graphs illustrating filter efficiency versus engine load indicate the slope of the SOF filter efficiency was smaller in magnitude than the TPM and SOL and SO4, fractions, which had similar slopes. The different slope of the SOF filter efficiency indicates other influences may be involved with the reduction in the SOF through the trap. Particle size distribution measurements in diluted exhaust revealed particle formation downstream of the trap.

Several sources of variation in quantitative analytical ferrography are investigated. A standard ferrography analysis procedure is developed. Normalization of ferrographic data to account for the amount of oil used to make the ferrograms is discussed. Procedures to minimize the errors involved with calculating three quantitative ferrography parameters: the area covered by the large particles, AL (%/ml of oil), the area covered by the small particles, AS (%/ml of oil) and Area Under the Curve, AUC, (%-mm/ml of oil) are outlined. Ferrographic data are presented which show that the volume and dilution ratio of the oil sample being analyzed have a major effect on the accuracy of the analysis. Several variables which influence the area covered readings of the particle deposit on a ferrogram are discussed. The accuracy of quantitative analytical ferrography is assessed.

The present study investigates the pressure drop and filtration characteristics of wall-flow diesel particulate monoliths, with the aid of a mathematical model. An analytic solution to the model equations describing exhaust gas mass and momentum conservation, in the axial direction of a monolith cell, and pressure drop across its porous walls has been obtained. The solution is in very good agreement with available experimental data on the pressure drop of a typical wall-flow monolith. The capture of diesel particles by the monolith, is described applying the theory of filtration through a bed of spherical collectors. This simple model, is in remarkable agreement with the experimental data, collected during the present and previous studies, for the accumulation mode particles (larger than 0.1 μm).