Fuel Property, Emission Test, And Operability Results From .
NREL/CP-540-36363. Posted with permission.Presented at the 2004 SAE Powertrain & Fluid Systems Conference & Exhibition,October 2004, Tampa, Florida2004-01-2959Fuel Property, Emission Test, and Operability Results from aFleet of Class 6 Vehicles Operating on Gas-To-Liquid Fuel andCatalyzed Diesel Particle FiltersTeresa L. Alleman, Leslie EudyNational Renewable Energy LaboratoryMatt Miyasato, Adewale OshinugaSouth Coast Air Quality Management DistrictScott Allison, Tom CorcoranInternational Truck and Engine CorporationSougato Chatterjee, Todd JacobsJohnson MattheyRalph A. Cherrillo, Richard Clark, Ian VirrelsShell Global Solutions (US) Inc.Ralph Nine, Scott WayneWest Virginia UniversityRon LansingYosemite WatersCopyright 2004 SAE InternationalABSTRACTA fleet of six 2001 International Class 6 trucks operatingin southern California was selected for an operability andemissions study using gas-to-liquid (GTL) fuel andcatalyzed diesel particle filters (CDPF). Three vehicleswere fueled with CARB specification diesel fuel and noemission control devices (current technology), and threevehicles were fueled with GTL fuel and retrofit withJohnson Matthey’s CCRT diesel particulate filter. Noengine modifications were made.Bench scale fuel-engine compatibility testing showed theGTL fuel had cold flow properties suitable for year-rounduse in southern California and was additized to meetcurrent lubricity standards. Bench scale elastomercompatibility testing returned results similar to those ofCARB specification diesel fuel. The GTL fuel met orexceeded ASTM D975 fuel properties.Researchers used a chassis dynamometer to testemissions over the City Suburban Heavy Vehicle Route(CSHVR) and New York City Bus (NYCB) cycles. TheGTL- fueled vehicles were tested with and without theCDPFs to isolate fuel and aftertreatment effects.All emission changes are compared to the CARBspecification diesel baseline. Over the CSHVR cycle,GTL fuel (no filter) reduced all regulated emissions, withoxides of nitrogen (NOx) reductions of 8% andparticulate matter (PM) reductions of 33%. Over theNYCB cycle, GTL fuel (no filter) reduced NOx and PM by16% and 23%, respectively. Combining GTL and CDPFfurther reduced all regulated emissions, with NOx andPM reductions of 14% and 99%, respectively, on theCSHVR cycle. Vehicles tested over the NYCB cycle onGTL fuel and CDPF produced NOx and PM reductions of20% and 97%, respectively.INTRODUCTIONGas-to-liquid (GTL) technology has been used for manyyears to synthesize hydrocarbons from natural gas.Recently, interest has grown in the production of GTLfuels and their emission reduction benefits. Severalcompanies produce or have produced GTL fuels,including Shell, Sasol, ExxonMobil, and others.1Many studies have examined the impact of GTL fuel onexhaust emissions from light- and heavy-duty vehiclesand engines (summarized in Reference 2). In a majorityof cases, GTL fuel produced a reduction in regulatedemissions (hydrocarbons [HC], oxides of nitrogen [NOx],carbon monoxide [CO], particulate matter [PM])compared to conventional diesel fuel.
Much of the emission data reported have come fromshort-term studies, where the engine/vehicle has beenswitched to GTL fuel from conventional diesel fuel for thepurposes of collecting emission test results. Uponconcluding the tests, the engine/vehicle is then switchedback to conventional diesel fuel. Thus, the long-termeffect of GTL fuel on engine systems has not beenadequately quantified.FUEL PROPERTY TESTINGPrevious studies of GTL diesel fuel do not always listcomplete fuel properties or test methods.2 The fuel usedin this study was tested to determine physical andchemical properties. In addition, researchers performedelastomer compatibility testing to characterize the impactof GTL fuel on fuel system elastomers.FUEL PRODUCTION TECHNOLOGY – Shell GlobalSolutions (US) Inc. provided the fuel that was used forfuel property and emission testing, and on-road use.The SMDS (Shell Middle Distillate Synthesis) process iswell documented, so only a brief description is offeredhere.3 The process is illustrated in Figure 1. The processwas developed at Shell Research & Technology CentreAmsterdam and is comprised essentially of three stages:Manufacture of synthesis gas (hydrogen carbonmonoxide–with a H2:CO ratio of approximately two) fromnatural gas by non-catalytic auto-thermal partialoxidation using, for example, the Shell GasificationProcess.Wax synthesis from CO H2 by Heavy ParaffinSynthesis (HPS), followed by flash distillation toseparate light ends (e.g., liquefied petroleum gas).Cracking of wax to distillates by Heavy ParaffinConversion (HPC), where the boiling range and qualityof the products can be adjusted to produce eitherkerosene or atmospheric gas oil (diesel).A recent modification to this process, designated asSMDS-2 offers an improved HPS (Heavy ParaffinSynthesis) catalyst, which will enable the manufacturersto increase production capacity considerably. In addition,adjusting the severity in the hydrocracking/isomerization(HPC) stage allows control of the n- to iso- paraffin ratioin the final product.Figure 1. Schematic illustration of Shell SMDS process.CH4NaturalGasCO 2H2SyngasSyngasmanufacturemanufactureSGP– CH2 esNapthaKeroseneGasoilLube oilfeedstockFUEL PROPERTY TEST RESULTS - The fuel wastested for a wide range of properties, such ascomposition, energy content, cold flow properties, andelastomer compatibility. All fuel property testing wasperformed at Southwest Research Institute in SanAntonio, TX.Except for elastomer compatibility, which will bediscussed separately, the test results are compiled inTable 1. Where applicable, the ASTM D975 specificationis also listed.The fuel composition was tested through elementaltesting and hydrocarbon determination. GTL fuel iscomposed of carbon and hydrogen. The fuel H/C ratio isabout 2.1, about 16% greater than conventional dieselfuel. The high H/C ratio is due to the near zero aromaticcontent of the GTL diesel fuel.4 As with most GTL fuels,the Shell GTL has near zero sulfur content.The very low aromatic content and/or the high H/C ratioof diesel fuel have been shown to reduce NOx and PMemissions in previous studies.5,6,7 Thus, testing with GTLfuel is likely to result in reductions in NOx and PMemissions.Fuel sulfur reductions also result in PM emissionreductions, though with diminishing returns as sulfurcontent becomes very low.6 In newer technologyengines, the near zero sulfur content of GTL fuel mayprove more beneficial by enabling sulfur sensitiveemission control devices.GTL fuels have reduced densities compared toconventional diesel fuels,2 which have been shown toreduce the PM emission in older technology engines.6,7Low density fuels, such as GTL fuel, may alter the fuelmass flow rates.7 Previous GTL fuel studies have notnoted adverse effects on engine operation as a result ofthe lower fuel density.9,10,11The cetane number of GTL fuels is most often reportedas 74, much higher than conventional diesel fuels.12GTL fuel is composed almost wholly of paraffins. Nparaffins are known to have very high cetane numbers,while iso-paraffins have lower cetane numbers.13Increasing cetane number has been linked to a decreaseor no change in NOx emissions. The effect appears to bedepend on engine model year, with a less prominenteffect on newer technology engines.5,6,7
Table 1. Fuel properties of Shell GTL fuel.PropertyTest MethodResultsDensity, g/mLAPI GravityViscosity, cSt at 40oCFlash Point, oCSulfur, ppmCarbon to Hydrogen ratioSFC Aromatics, mass%MonoaromaticsPolynuclear aromaticsTotal aromaticsHydrocarbon types, vol%AromaticsOlefinsSaturatesHeat of combustion, BTU/lbGrossNetCetane NumberASTM D4052ASTM D287ASTM D445ASTM D93ASTM D54530.7838493.468890.52.13Autoignition temperature, oCIgnition delay time, secondsDistillation, oCIBPT10T50T90FBPCloud Point, oCPour Point, oCCold filter plugging point (CFPP), oCLow temperature flow test (LTFT), oCWater and SedimentCopper CorrosionPeroxide number, mg/kgGum content, mg/100mLAsh, mass%Carbon residue, %massAcid number, mgAccelerated stability, mg/100mLHigh temperature stability,180 min, Avg % ReflectanceScuffing Load Ball-on-CylinderLubricity Evaluator, scuff load, gHigh Frequency Reciprocating Rig,wear scar, mm* Results from subsequent test.Highly paraffinic GTL fuels may have cold flowproperties that are not acceptable for operationthroughout the United States. The test fleet in thisproject operated exclusively in southern California(metro Los Angeles area), where the cold flowoperability of GTL fuel was not an issue.Other properties, such as gum, ash, and water andsediment are in line with other diesel fuels and are notexpected to impact operations. A reduced T90/T95temperature has been shown to have a small impact onASTM D5186ASTM D1319ASTM D240ASTM D613IQTASTM E6591.9-4.152 minimum500 maximum1.4 0.11.41.01.098.020,24618,87879.577.9207.2141.3ASTM D2500ASTM D97IP 309ASTM D4539ASTM D1796ASTM D130ASTM D3703ASTM D381ASTM D482ASTM D524ASTM D664ASTM D2274208.9246.7299.0331.1343.21-6-1-2 0.021A 15.9 0.0010.03 0.50.4ASTM D6468100ASTM D60782,750*ASTM D60790.395*ASTM D86ASTM D975Specification35 maximum40 minimum282-338-3 maximum0.01 maximum0.15 maximumemissions.7,14 For GTL fuel, any impact based onT90/T95 temperature is likely obscured by other fuelproperties such as paraffin content and cetane number.Typically, unadditized GTL fuels have poor lubricitiesdue to a lack of polar molecules, but respond well toadditives.9,15 The fuel used in this work was additized.BENCHELASTOMERCOMPATIBILITYTESTRESULTS – Bench scale elastomer testing was used tocomplement the real-world data gathered from
introduction of GTL fuels into a vehicle fleet for manymonths.International Truck and Engine Corporation contributedseveral sets of new elastomers for the compatibilitytesting. The elastomers were from the DT466 engineand were identical to those found in the study vehicles.The GTL fuel had the properties listed in Table 1. Thecommercial CARB specification diesel fuel was a typicaldiesel fuel meeting CARB diesel specifications.Properties for this fuel are in Table 2.Table 2. CARB specification diesel fuel properties usedfor elastomer testing.PropertyDensity, g/mLAPI GravityFlash Point, oCSulfur, ppmCarbon, mass%Hydrogen, mass%Oxygen, mass% by differenceSFC Aromatics, mass%Polynuclear AromaticsTotal AromaticsHydrocarbon types, vol%AromaticsOlefinsSaturatesHeat of Combustion, BTU/lbGrossNetCetane NumberCloud Point, oCPour Point, oCDistillation, oCIBPT10T50T90FBPGum Content, mg/100mLTest MethodASTM D4052ASTM D287ASTM D93ASTM D5453ASTM D5291ASTM D5186ASTM D1319ASTM D240ASTM D613ASTM D2500ASTM D97ASTM D86ASTM D381Results0.829938.97015386.4213.64 1.8261.4323.6348.413.2Elastomer testing included hardness, volume, radialthickness changes, elongation, reversion, bend testing,and sediment observation. Three identical elastomerswere used for each test, under each of the three testconditions in addition to a set for the control case (nofuel exposure). The elastomers were in new, unusedcondition prior to the start of the tests.1. CARB specification diesel fuel at 60 C for 1,000hours2. GTL fuel at 60 C for 1,000 hours3. CARB diesel fuel at 60 C for 500 hours, followedby GTL fuel at 60 C for 500 hours, 1,000 hourstotalThe CARB specification diesel fuel exposure followed byGTL fuel exposure was selected to investigate the effectof changing fuels on elastomer properties. The impact ofdiesel fuel aromatic compounds on the swell ofelastomers has been previously documented.16 Dieselfuel properties may have a lesser effect on fluorocarbonelastomers than gasoline, but investigation is stillneeded. 17Four types of elastomers were tested and indicated asA, B, C1, and C2. Elastomer A was a seal, composed ofViton, VA-154-95. Elastomers B and C1 were also seals,composed of Viton, VA-153-90. Elastomer C2 was acushion, composed of hydrogenated nitrile buna rubber(HNBR). The control results were collected fromelastomers not exposed to fuel.Results of the bench scale elastomer testing are inAppendix A-1. After exposure to the fuel(s), no sedimentwas recorded for any of the four types of elastomers, norwas any reversion observed. The elastomers also allpassed the bend test. The reported hardness changeswere minor for all four elastomers under each of thethree test conditions.Elastomers A, B, and C1 did not show an appreciablechange in volume after exposure to any of the test fuels.Elastomer C2 showed some swelling upon exposure tothe CARB specification diesel fuel, likely due to the 22%aromatic content of the fuel. However, no swelling wasobserved for C2 during exposure to the GTL alone or theCARB specification diesel followed by the GTL fuel.The radial thickness of the elastomers did not changewith exposure to the test fuels. This is an interestingpoint to note, as elastomer C2 swelled with exposure tothe CARB specification diesel fuel. The increase involume of elastomer C2 was not swelling along theradial axis, but an increase in the height of theelastomer.A simple statistical analysis was performed on theelongation results. The results were analyzed using atwo-tailed t-test, assuming equal variances, at the 95%confidence level. The p-values are shown in Table 3.Note that the symbol CARBÆGTL indicates exposure tocondition 3 or CARB specification diesel followed byGTL fuel.There were no significant changes in the elongation ofelastomer A, either compared to the control or betweenthe fuels. For the most part, no changes in theelongation of elastomer B were observed. However,between the control and the GTL fuel and the controland the CARB specification diesel, small changes in theelongation for elastomer B were noted. No changeswere recorded for C1.For C2, only one small change was recorded for theCARB specification diesel compared to the CARBÆGTLexposure. Elastomer C2 showed a higher overallvariability compared to the other elastomers, possiblydue to the chemical composition of the HNBR.Unfortunately, more detailed information about thedegree of hydrogenation and acetonitrile content of C2 isnot available.
All four elastomers held up well to the bench testing thatwas performed in this study. Based on the results fromthis portion, there was little concern about introducingthe GTL fuel to the fleet vehicles. Additionally, no vehiclepreparation was performed prior to the switch, such asreplacing the elastomers.Table 3. P-values for elastomer elongation 2C2FuelsControl to GTLControl to CARBÆGTLControl to CARBGTL toCARBÆGTLGTL to CARBCARBÆGTL toCARBControl to GTLControl toCARBÆGTLControl to CARBGTL toCARBÆGTLGTL to CARBCARBÆGTL toCARBControl to GTLControl toCARBÆGTLControl to CARBGTL toCARBÆGTLGTL to CARBCARBÆGTL toCARBControl to GTLControl toCARBÆGTLControl to CARBGTL toCARBÆGTLGTL to CARBCARBÆGTL toCARB201 and 204 have the lowest percentage of highwaymiles. If these vehicles were both “baseline” or both“test”, the real-world fuel economy might be biased, aslower fuel economy is recorded during city driving. Thus,vehicle 201 was in the “baseline” group and vehicle 204was in the “test” group.Table 4. Vehicle and engine specifications for YosemiteWaters test .264No0.043YesFLEET PROPERTIESYosemite Waters in Fullerton, CA provided the studyvehicles for this project. The participating vehicles weresimilar and operated out of a single location. Vehicle andengine specifications are shown in Table 4.Each Yosemite Waters vehicle operates on a dedicated10-day route with varying degrees of city and freewaydriving. Thus, the driving characteristics of each vehiclewere somewhat unique (see Table 5). Also shown inTable 5 are the vehicles selected to operate on CARBspecification diesel fuel and the vehicles selected tooperate on GTL fuel with the emission control devices.One factor in designating the vehicles as “baseline” or“test” was the percentage of highway miles. VehiclesVehicleManufacturerModel numberBody manufacturerVehicle activityTransmission typeTransmission manufacturerTransmission ModelEngineManufacturerEngineConfigurationModel yearPeak PowerPeak TorqueInternational4300-DT466HackneyPickup and delivery5-speed automaticAllison2000InternationalDT466Inline 6 cylinder2001195 hp @ 2,300 rpm520 ft-lbTable 5. Driving characteristics for test vehicles inYosemite Waters fleet.Vehicle206Fuel/EmissionControlCARB, NoneCARB, NoneCARB, NoneGTL, CCRTfilterGTL, CCRTfilterGTL, CCRTfilter% HighwayMiles over10-day cycle367574Total MilesDriven over10-day cycle5327521,030616808266777837The other vehicles had more similar percentages ofhighway miles and were divided so that consecutivevehicle numbers were in the same category (i.e. 201,202, and 203 were baseline).EMISSION CONTROL DEVICESThe test vehicles were operated on GTL fuel for at leasttwo weeks prior to installing the emission control devicesto ensure no residual CARB specification diesel fuelremained in the fuel system.Johnson Matthey supplied the emission control devices–CCRT filters (Catalyzed Continuously RegeneratingTechnology). The CCRT filter is a diesel oxidationcatalyst followed by a wall-flow catalyzed soot filter.22Testing has shown that the CCRT filter has good lowtemperature performance.The good low temperature performance was animportant characteristic in selecting the CCRT filter for
Vehicle 205On-board dataloggers were used to evaluate the efficacyof the CCRT filters by continuously measuring exhaustbackpressure and temperature over the road.Figure 2. Exhaust temperature histogram for vehicle 204from January 2003 through June 2004.6040040200200050Figure 4. Exhaust temperature histogram for vehicle 206from December 2003 through June 2004.1400100Vehicle 206120080100060800600404002020000100001000100 150 200 250 300 350 400 450 500Exhaust Temperature, oCFrequency, AbsoluteAs shown in Table 5, vehicle 204 travels on the highway61% of the time during its 10-day route. Of the three testvehicles, the average exhaust temperature of thisvehicle is expected to be the lowest. Figure 2 presents ahistogram of the data collected from vehicle 204 duringthe project. The shaded area indicates that the vehiclehas an exhaust temperature above about 210 C for 40%of its operating time. Similar histograms are shown inFigures 3 and 4 for vehicles 205 and 206. The 40% cutpoint temperature for vehicles 205 and 206 is muchhigher than for vehicle 204 ( 230 C and 240 C,respectively).80600Time at Temperature, %DATALOGGER RESULTS10080050Time at Temperature, %The exhaust temperature and pressure of vehicle 204was monitored for several months to insure the filterperformance was acceptable. Exhaust pressure andtemperature histograms collected over several monthsshowed stable filter operation. After analyzing this data,vehicles 205 and 206 were retrofit as well.Figure 3. Exhaust temperature histogram for vehicle 205from December 2003 through June 2004.Frequency, Absolutethis project. Because vehicle 204 had a low percentageof highway miles compared to the other fleet vehiclesand subsequently, a low average exhaust temperature(average exhaust temperature 210 C), it was selectedto be the first vehicle retrofit.0100 150 200 250 300 350 400 450 500oExhaust Temperature, C8060006040004020002000500100 150 200 250 300 350 400 450 500oExhaust Temperature, CTime at Temperature, %Frequency, AbsoluteVehicle 2048000The peak exhaust backpressure data can be used toshow if filter performance is deteriorating over time. Asthe filter becomes plugged, the peak backpressureshould increase. Figures 5, 6, and 7 illustrate the peakbackpressure for Yosemite
Jan 01, 2003 · short-term studies, where the engine/vehicle has been switched to GTL fuel from conventional diesel fuel for the purposes of collecting emission test results. Upon concluding the tests, the engine/vehicle is then switched back to conventional diesel fuel. Thus, the long-term effect of GTL fuel on en
Fuel transfer pump (35) is mounted on the back of unit injector hydraulic pump (1). The fuel transfer pump pushes pressurized fuel out of the outlet port and the fuel transfer pump draws new fuel into the inlet port. Fuel is drawn from fuel tank (12) and flows through two micron fuel filter (11) . Fuel flows from fuel filter (11) to the inlet .
Fuel Pressure: Fuel Pressure Regulator and System Pressure. Fuel System: Pumps, Relays . significant volume of fuel may come out. Be ready to catch all the gas in the filter . The 3 main things to check in the fuel circuit are the fuel pump relay, and the 2 fuel pumps. 1. Fuel Injection Relay Test
Ecotoxicological characterization factor [PDF·m3·day/kg]: Emission to urban air Emission to cont. rural air Emission to cont. freshwater Average 1,8E 02 1,8E 02 4,5E 02 Worth Case 4,6E 02 4,6E 02 1,2E 03 Emission to urban air Emission to cont. rural air Emission to cont. freshwater cancer non-canc. total cancer non-canc. total cancer non-canc .
data on the amount of the fuel combusted and a country specific emission factor for each fuel. Country-specific emission factors are developed by taking into account country-specific data, such as: carbon content of the fuels used, carbon oxidation factors and fuel energy content. Emission factor determination for non-CO 2
5-6 FUEL SYSTEM AND THROTTLE BODY FUEL TANK LIFT-UP Remove the front seat. ( 7-4) Remove the fuel tank mounting bolts. Lift and support the fuel tank with its prop stay. FUEL TANK REMOVAL Lift and support the fuel tank with its prop stay. (L7above) Disconnect the fuel pump lead wire coupler 10. Pla
ATJ/F-24 fuel blend appears to result in accelerated wear in fuel-lubricated rotary fuel injection pumps. At various fuel inlet temperatures, the use of maximum concentration CI/LI in a 30% ATJ/F-24 fuel blend appears to retard the accelerated wear observed in prior fuel -lubricated rotary fuel injection pump studies.
emission characteristics of marine diesel engines. Keywords: marine diesel engine; exhaust emissions; fuel-based emission factor; energy-based emission factor; specific emission 1. Introduction Seaborne trade can bring huge economic benefits to the world, accounting for more than 80% of global trade, and it is still growing [1,2].
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