PB92-153055 Emissions and Fuel Economy of DOE Flex-Fuel Vehicles (U.S.) Environmental Protection Agency, Research Triangle Park, NC 1992 V I U.S. Deoartment of Cmmktcc wf WlfVI mnnfl «r» w^r ------- TECHNICAL REPORT DATA 1. REPORT NO. EPA/600/A-92/042 2. 3.' PB92-153055 4. TITLE AND SUBTITLE EMISSIONS AND FUEL ECONOMY OF DOE FLEX-FUEL VEHICLES 5.REPORT DATE 6.PERFORMING ORGANIZATION C00E 7. AUTHOR(S) F.M. Black, USEPA T. Kleindienst, ManTech 8.PERFORMING ORGANIZATION REPORT NO. 9 PERFORMING ORGANIZATION NAME AND ADDRESS Atmospheric Research and Exposure Assessment Laboratory Office of Research and Development U.S. Environmental Protection Agency Research Triangle Park, N.C. 27711 10.PROGRAM ELEMENT NO. 11. CONTRACT/GRANT NO. 12. SPONSORING AGENCY NAME AND ADDRESS Atmospheric Research and Exposure Assessment Lab - RTP Office of Research and Development U.S. Environmental Protection Agency Research Triangle Park, N.C. 27711 13.TYPE OF REPORT AND PERIOD COVERED • Cmnf. ri i— U. SPONSORING AGENCY COOE J EPA/600/09 15. SUPPLEMENTARY NOTES 16. ABSTRACT The U.S. Department of Energy and the U.S. Environmental Protection Agency have established, through a Memorandum of Understanding, a coordinated framework for collaborative research examining the impact of alternative motor vehicle fuels on air quality and risk to public health and welfare. A cooperative effort to examine the emissions and fuel economy of DOE flex-fuel vehicles, capable of operating on a variety of liquid fuels, and the atmospheric chemistry of the emissions, will begin in January, 1992. During the first year, emissions will be characterized for 6 vehicles, 2 conventional fuel baseline vehicles and 4 flex-fuel vehicles, using up to 9 fuels. Additionally, a dual-chamber irradiation facility will be constructed to support future study of the atmospheric chemistry of the emissions. These studies will examine the formation of ozone and toxic compounds. A detailed description of the experimental procedures to be used is provided. 17. KEY WORDS AND DOCUMENT ANALYSIS a. DESCRIPTORS b. IDENTIFIERS/ OPEN ENDED TERMS c.COSAT I 18. DISTRIBUTION STATEMENT RELEASE TO PUBLIC 19. SECURITY CLASS (This Report) UNCLASSIFIED 21.NO. OF PAGES 15 20. SECURITY CLASS (This Paqe) UNCLASSIFIED 22. PRICE ------- EPA/600/A-92/042 Emissions and Fuel Economy of DOE Flex-Fuel Vehicles Frank Black Mobile Source Emissions Research Branch U.S. Environmental Protection Agency Research Triangle Park, N.C. Taduesz Kleindienst ManTech Environmental Technology, Inc. Research Triangle Park, N.C. ------- ABSTRACT The U.S. Department of Energy and the U.S. Environmental Protection Agency have established, through a Memorandum of Understanding, a coordi- nated framework for collaborative research examining the impact of alternative motor vehicle fuels on air quality and risk to public health and welfare. A coop- erative effort to examine the emissions and fuel econ- omy of DOE flex-fuel vehicles using a variety of potential fuels, and the atmospheric chemistry of the emissions, will begin in January, 1992. During the first year, emissions will be characterized for 6 vehicles, 2 conventional fuel baseline vehicles and 4 flex-fuel vehi- cles, using up to 9 fuels. Additionally, a dual-chamber irradiation facility will be constructed to support future study of the atmospheric chemistry of the emissions. These studies will examine the formation of ozone and toxic compounds. A detailed description of the experi- mental procedures to be used is provided. THE ALTERNATIVE MOTOR FUELS ACT OF 1 988 requires the Secretary of the Department of Energy (DOE) to ensure that Federal Government motor vehicle fleets include the maximum number practical of vehicles compatible with alternative fuels such as methanol, ethanol, and compressed natural gas. The Act further requires the Secretary, in cooperation with the Environ- mental Protection Agency (EPA) and the National High- way Traffic Safety Administration (NHTSA), to conduct a study examining the safety, fuel economy, and emis- sions of such vehicles. DOE and EPA have established a Memorandum of Understanding agreeing to a frame- work for collaborative research examining the charac- teristics of emissions from motor vehicles using alternative fuels, and the atmospheric chemistry of the emissions. This paper describes experimental protocols for planned 1992 activities. Initial program efforts will include characterization of tailpipe and evaporative emissions from 6 motor vehicles with up to 9 fuels. Laboratory simulations of roadway driving conditions will be used to produce samples repressntatjve of automotive evaporative and tailpipe emissions. Emissions characterization will in- clude measurerr»ents 0f total hydrocarbon (THC), car- bon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx). methanol (MeOH), ethanol (EtOH), methyltertiarybijty| ether (MTBE), aldehydes (RCHO), and over 200 in«^jvj,jUal hydrocarbon compounds. Ve- hicle fuel econoi>,y wj|| also be characterized. Addition- ally, irradiation chamber facilities suitable for studying the atmospheric chemistry of the emissions will be designed, constructed, and characterized. technical approach - emissions CHARACTERISATION Emission ^ests will be conducted at the EPA Mobile Source EEmjcSjons Research Branch (MSERB) laboratory located at Research Triangle Park, N.C. In addition to all Of the equipment required for measuring regulated emissions (THC, CO, NOx, CO2) from auto- mobiles, this laboratory is equipped with a temperature controlled chassis dynamometer enclosure permitting variation of driving simulation ambient temperature, and all of the equipment and instrumentation required for measuring aldehyde, alcohol, ether, and detailed HC emission rates. Although both exhaust and evaporative tests will be conducted according to the Federal Test Procedure (FTP) ^ the fuels and ambient test tempera- tures may be varied outside the parameters prescribed for emissions certification (1). * TEST VEKjicles AND FUELS-Six 1991 motor vehicles will be studied including a conventional gaso- line and 2 alcohol f|ex-fuel Ford Taurus automobiles, and a conventional fUel and 2 alcohol flex-fuel Chevrolet Lumina automobiles. Nine fuels with specifications * Numbers in Parentheses indicate references at end of the paper. Black P.ttc 1 ------- provided in Table 1 will be used during the 1992 program. The 4 reformulated gasolines will be provided from a set of fuels examined in the Auto/Oil Air Quality Improvement Research Program (2). A total of 40 emissions tests will be completed as indicated in Table 2. Table 3 provides an overview ot the activities of a typical test week. Table 1. Program Test Fuels. 1. Indolene (EPA emissions certification fuel) 2. CAAA Summer Baseline Unleaded Gasoline 8.7 psi RVP, 87.3 (R + MW2 octane, 339 ppm sulfur, 1.53% benzene, 32.0% aromatic, 9.2% olefin, 58.8% paraffin 3. M85 (85% methanol, 15% unleaded gasoline) 4. E10 (10% ethanol, 90% unleaded gasoline) 5. ESS (85% ethanol, 15% unleaded gasoline) 6. Reformulated gasoline 1 (Auto/Oil code C) 8.7 psi RVP, 288 F T90, 15.4% MTBE, 43.8% aromatic, 3.3% olefin, 37.5% paraffin 7. Reformulated Gasoline 2 (Auto/Oil code J) 8.6 psi RVP, 356 F T90, 14.9% MTBE, 21.4% aromatic, 4.0% olefin, 59.7% paraffin 8. Reformulated Gasoline 3 (Auto/Oil code N) 8.8 psi RVP, 292 F T90, 13.9% MTBE, 21.4% aromatic, 5.7% olefin, 59.0% paraffin 9. Reformulated Gasoline 4 (Auto/Oil code M) 8.7 psi RVP, 356 F T90, 14.5% MTBE, 18.0% aromatic, 21.8% olefin, 45.7% paraffin VEHICLE PREPARATION-^ major goal of this program is assessment of the impact of varied fuel formulations on motor vehicle emissions. Each vehicle will be tested with multiple fuels. To assure that fuel memory effects are minimized, each vehicle will be preconditioned with each test fuel prior to emissions evaluation using the following sequence; 1. Remove the evaporative canister from the vehicle Table 2. Year 1 Test Matnx. Vehicles Fuels No. of Tests Conv. Baseline -1,2 *ndolene. Reform, Gas. 3 4 FFV • 3,4,5,6 Indolene, Summer Bise., Reform. Gas, 1,2,3,4 36 M85. E10, £85 Table 3. Typical Test Week. Day 1 - quality assurance Day 2 - vehicle conditioning with fuel 1 Day 3 - emission tests with fuel 1 Day 4 • vehicle conditioning with fuel 2 Day 5 - emission tests with fuel 2 Week 2 would involve a simibr sequence with fuels 3 and 4, and so on. and purge with 300°F nitrogen at 20 l/min until the incremental weight loss is less than 1 g in 30 min (typically takes 3-4 hrs and removes 100 to 120 g of adsorbed gasoline vapors). 2. Drain the vehicle fuel tank of the previous test fuel, add 5 gal of the following test fuel, and complete an Urban Dynamometer Driving Schedule (UDDS) (initial 1372 sec of the FTP driving schedule to be described later) (1). Drain and refuel to 40% of capacity with the test fuel. Return the "purged" canister to the vehicle. Heat the vehicle fuel tank from 72°F to 120°F using a 2-hr linear temperature ramp. Repeat as necessary (with refueling between each heat build) until the can- ister reaches a "break-through" load. "Break-through" is defined by monitoring the evaporative emission rate as a function of time, and noting when the slope of emissions versus time changes abruptly. Figure 1 pro- vides a typical "break-through" trace. 3. Drain the vehicle fuel tank and refuel to 40% of capacity. Complete a UDDS driving sequence followed Black Page 2 ------- o E a a ti c o U u c cs 0 UJ 1 (/) 72 to 120 F 2 hr ramp canister break-through 7K SO *0 ftC 9Q fO « »C 100 HO 'JO Time, min. Figure 1. Evaporative Canister "Break-through" Trace. by overnight soak in preparation for the FTP emissions tests described in the following discussion. EMISSIONS CHARACTERIZATION-Tailpipe and evaporative emissions will be examined using proce- dures defined for Federal light-duty motor vehicle emis- sions certification {1). Figure 2 provides a flow diagram of the the test sequence. After an overnight soak at the test temperature, a diurnal (Di) evaporative emis- sions test is completed, followed by a urban transient driving tailpipe emissions test, followed by a hot soak (HS) evaporative emissions test. Figure 3 provides a schematic of the chassis dynamometer test cell, and a speed versus time trace for the FTP transient driving schedule used to simulate urban driving conditions. The FTP driving schedule includes a cold engine start (after an overnight soak, see Fig. 2), 21.3 mi/h average speed, 2.4 stops/mi, 19% idle operation, 11.1 mi traveled, and 31.3 min duration (plus 10 min engine off soak period). The first 505 sec of the FTP driving schedule is com- monly refered to as test phase 1, the next 867 sec as test phase 2, and the final 505 sec as test phase 3. Evaporative Emissions Determination-Motor ve- hicle evaporative emissions are measured using a Sealed Housing for Evaporative Determination (SHED). The vehicle is sealed within the SHED enclosure and the Di arid HS emissions determined in accordance with the FTP (1). At the conclusion of each evaporative test, samples are taken from the SHED into a 60L Tedlar bag for gas chromatographic (GC) analysis of methanol, (^START^ FUEL DRAIN AND RU UN AND RLU 1 [PYNQ PRECONDITIONING}" 1 hour maximum ~1- COLD SOAK PARKING- 'S minutes maximum FUELING ~ DRAIN • 40 % RU t DIURNAL HEAT BUILD * HEAT FUEL 1 HOUR * 60 TO B4 DEG F EVAPORATIVE TEST NOT REQUIRED DIURNAL ENCLOSURE TEST "12-36 hours _r\ ICOID START EXHAUST TEST •0-1 hour EVAPORATIVE TEST HYDROCARBON NOT PERFORMED RUNNING LOSSES AS REQUIRED * * HOT start exhaust test HOT SOAK ENCLOSURE TEST 10 minutes "7 minutes Figure 2. Emissions Test Sequence. ethanol, MTBE, and detailed HCs, as appropriate. Sam- ples for THC analysis are taken directly from the SHED to a heated (235±15°F) FID (HFID). Evaporative THC emissions are reported as non-oxygenated THC by correcting the THC value for HFID response to methanol ior other oxygenates). The organic emission rates may also be reported as Organic Material Hydrocarbon Equiv- alent (OMHCE) according to equation 1 for methanol fuels (1): 14.3594 . . 14.228* OMHCEevap = HCoimass + 32 042 OHoi mass + HChS mass + ^2 042 14.2284 CHiOHhs mass (1) Black Page 3 ------- EVAPORATIVE SHED BAG FOflHC ROH ANALYSIS HLATfD HC no TEMPERATURE CONTROLLED TESTCaL Winn DYNAMOMETER SAGS • fOH HC. «0«. ROM ANALVS6 ANALYZERS ALDCHYDC CARTROGES KLATlD F® HLATfD TRANSH.R IHC HEATED TRANSFER UNES DILUTION TUNNEL tcriow ine ANALYZER Phase 1 Phase 2 JZ Q. E "O 30 0) a a cr> BOO Time, sec rrp 10 min Soak Phase 3 ft! Figure 3. Test Cell Configuration and Driving Cycle. where: HC Di mass and HC HS mass = Di and HS emissions hydrocarbon mass in grams, respectively, and CH3OH Di mass and CH3OH HS mass = Di and HS emissions methanol mass in grams, respectively; which assume that the evaporative Di emissions hydro- gen to carbon ratio is 2.33 and HS emissions hydrogen to carbon ratio is 2.2 (conforming with conventional gasoline standards). Similar calculations can be com- pleted for ethanol fuels using appropriate coefficients for ethanol. Di and HS evaporative emissions tests are con- ducted in conjunction with the FTP, as shown in Figure 2. Following an overnight soak in the Temperature Controlled Test Chamber (TCTC) at the test tempera- ture, the vehicle is pushed into the SHED for the Di test. During the Di test, tank fuel temperature is elevated using a 24°F/hr ramp, e.g., 40 to 64°F for a 40°F test, 60 to 84°F for a 70°F test, and 72 to 96°F for a 90°F test. The initial 1 992 program matrix (see Table 2) will examine Di evaporative emissions from 60 to 84°F, with tailpipe emissions examined at 70°F (as in Federal emissions certification). Following the Di test, the vehi- cle is pushed back into the TCTC and allowed to equilibrate at the test temperature. After temperature equilibiium is reached, the UDDS is run, followed im- mediately by the HS evaporative test. The SHED is not Black Page 4 ------- equipped to be operated at reduced ambient tempera- tures; therefore, a subambient (e.g. 40°F) evaporative emission test would be conducted at laboratory temper- atures near 70°F. This should have little effect on Di tests which are conducted with engine and fuel cold. HS tests, which begin with engine and fuel warm, should be somewhat affected in that the engine and fuel will not cool as rapidly as they would in a cooler environment. For a high temperature evaporative emis- sions test (e.g. 90°F), an appropriate Di temperature ramp (e.g. 72°F to 96°F) would be used and the SHED temperature for HS maintained at the elevated test temperature {e.g. 90°F). The Di and HS evaporative emission rates are combined according to equation 2 to permit comparisons with tailpipe exhaust rates. non-oxygenated HC by using a procedure to correct the THC value for FID response to alcohols (5). Tailpipe organic emissions rates may also be reported as OMHCE wherein total organic carbon mass is calculated according to equation 3 for methanol fuels which as- sumes that the hydrogen to carbon ratio of all tailpipe organic emissions is 1.85 (permits conformity with conventional gasoline emission standards) (1). Similar calculations can be completed for ethanol fuels using appropriate coefficients for ethanol and acetaldehyde. The FTP driving schedule includes three test phases: a cold start transient phase (505 sec.), a stabilized phase (867 sec.), and a hot start transient phase (505 sec.). There is a 10 minute engine-off soak period between phases two and three. Emissions from Evap. Emissions, a r (3.05'"P^dayX-hot soak emissions, a/trip) + diurnal emissions, s^ay 31.1 ™¥day (2) OMHCEt3;ip;pe =» HCmass + (CHzOHmass) + (HCHOmass) (3) Exhaust Emissions Determinations -- Vehicie ex- haust emission tests will be conducted using an electric chassis dynamometer {Horiba Instruments, Inc.) to sim- ulate vehicle road load. The dynamometer rolls are enclosed within a TCTC permitting vehicle soak and operation at temperatures from 20°F to 1 1 0°F as illustrated in Figure 3. Exhaust gases are sampled using a constant volume sampling (CVS) technique commonly used for vehicle emissions certification tests (1). A heated transfer tube is used within the TCTC to direct vehicle raw exhaust to a "dilution tunnel" where the exhaust is cooled and diluted prior to sampling for analysis. Ex- haust gas is thoroughly mixed in the dilution tunnel with 70°F dilution air. Total flow through the dilution tunnel is held constant (e.g. 750 CFM) . Aliquotes of the diluted exhaust are collected directly from the dilution tunnel at a constant flow rate over the duration of the test, permitting determination of pollutant mass emis- sion rates (g/mi) from sample concentration, total di- luted exhaust volume, and distance traveled. The sampling system has previously been qualified for quan- titative transfer of methanol, formaldehyde, and other compounds of interest at varied ambient temperatures from the motor vehicle tailpipe to the analytical instru- mentation (3,4). Regulated emissions (THC, CO, NOx, CO2) are sampled and analyzed using standard Federal certifica- tion procedures (1). THC emissions are reported as each phase are analyzed separately and then combined to calculate a "weighted" emission rate according to equation 4: ,/ r, + Yht+Ys , AS Ywm = 0.43 -^— + 0.57 n (4) Dq(+Ds Dfjt+Ds where: Ywm = weighted mass emissions of each pollutant, i.e. HC, CO, NOx, CO2, MeOH, etc. in grams per vehicle mile, Vet = mass emissions calculated from the transient phase of the cold start test, in grams per test phase, Ys = mass emissions calculated from the stabilized phase of the cold start test, in grams per test phase, Yht = mass emissions calculated from the transient phase of the hot start test, in grams per test phase, Dct = the measured driving distance during the tran- sient phase of the cold start test, in miles, Ds = the measured driving distance during the stabi- lized phase of the cold start tust, in miles, and Black Page 5 ------- Dht = the measured driving distance during the tran- sient phase of the hot start test, in miles. Fuel Economy-Fuel economy is evaluated both in terms of miles traveled per gallon of fuel consumed (mi/gat) and in terms of BTUs of energy consumed per mile traveled (BTU/nni). Mi/gal fuel economy is deter- mined using classical carbon balance equations with appropriate carbon weight fraction for the varied fuels. Equations are presented in Figure 4. Energy based fuel economy is ralculated using appropriate energy densi- ties for the van.?d fuels. Equations are presented in Figure 5. Because of the lower energy densities of the alcoho' fuels, reduced mi/gal fuel economies are ex- pected, depending on the fraction of the fuel that is alcohol. However, improved energy effiencies are pos- sible with alcohol fuels, off-setting somewhat, the reduced fuel energy densities. Table 4 provides exam- ples of fuel economies observed with FFVs using gas- oline and M85 {05% methanol, 15% gasoline) fuels. Analytical Chemistrv--As previously discussed, THC, CO, NOx, and CO2 are sampled and analyzed using standard Federal emissions certification proce- dures (1). Samples for exhaust detailed HC measure- ments are collected by pumping a constant aliquot of the diluted exhaust from the CVS into Tedlar bags for subsequent analysis by gas chromatography. Gas chro- matographs equipped with flame ionization detectors (FIDs) are used for the detailed HC analysis (6). Each instrument uses three analytical columns -two packed columns that resolve C1 and C2 HCs, and a capillary column that resolves C3-C 12 HCs. The method pro- vides quantitation of over 200 HC compounds. Figure 6 provides a shematic of the chromatographic system for detailed HC analysis. Aldehyde compounds, sampled from the dilution tunnel through a heated (235±15°F) sample line (at 1 LPMl, are collected on dinitrophenyl- hydrazine (DNPH)- coated silica gel cartridges. Individual aldehydes, which are collected on the cartridge as DNPH aldehyde derivatives, are subsequently analyzed by high perfor- mance liquid chromatography. This sampling technique and analytical method permits quantitative determina- tion of 1 5 individual aldehydes (7). Figure 7 provides a schematic of the chromatographic system for aldehyde analysis. Alcohols are sampled using water impingers and analyzed using a previously described GC method (8). Ethers are sampled into Tedlar bags, similar to the detailed HC practice, for subsequent GC analysis using previously described GC procedures (9,10). Figures 8 g Carbon / gal fuel n.tYgal = 0 Carbon in exhaust / mi K1 (fuel g 1 flail mi/gal = K1 (a OM / mi! + K2 (g CO / mi) + K3 Ig C02 t ml! K1 = Fuel carbon weiQht fraction = 0.866 (gasoline), 0.375 (MeOH). 0.449 IM05) K2 = CO carbon weight fraction = 0.429 K3 = C02 carbon weight fraction = 0.273 Figure 4. Carbon-Balance Fuel Economy. 8.34 * heating value. BTU/lb * fuel density. g/ml BTU/mi = fuel economy, mi/gal where: Heating Value. Density, BTU/lb g/ml MeOH 8.600 0.79 Gasoline 18.700 0.74 M85 10,115 0.78 Figure 5. Energy-Based Fuel Economy. Table 4. Example FFV Fuel Economies. ; Fuel mi/gal BTU/mi J 1 j MO i 21.8 5,305.0 j 1 ! MS5 I 13.3 i 4,996.8 j and 9 provide schematics of the chromatographic sys- tems used for alcohol and ether analyses, respectively. Black Page- 5 ------- T <5> Gauge Ak Solenoid 1 Solenoid 2 Solenoid 3 ¦ Vacuum Helium Carrier /Q_) \5cm3y Aio^/T Pcropak Catumn je Sample In Sample ) Pump FO Air Hydrogen Column Helium Gamer Silica Column Air Hydrogen Figure 6. Ci to C12 Hydrocarbon Chromatography. Quadrex 007 Silicone Fused Silica Column FID Air Hydrogen Back Pressure , / Regulator Split Injector Split Vent | Flow Helium Controller Carrier Figure 8. Alcohol Chromatography. Injection Valve Waste ¦ Sample Loop — Guard Column rumps Water Acctonitrile Reservoir Reservoir OO, Autosamplor Zorbax 00S Analytical Column 360 nm UV Detector Waste Liquid Nitrogen Cooling Hydrogen Nutech Temperature Controller Toggle Sample Valve Toggle Valve Hydrogen Flush Vacuum Gauge ¦>. Vacuum -* O- Pump Toggle Valve Vacuum Reservoir Togo1® Valve ~'10 1\ 002 9* ® 2 Cryogenic g £ 3 p Focusing Hydrogen [ / I 7 ( (p Jjl FlD Flow Air Hydrogen i / ( MU 15 % TCLP \ Firebrick * Column P'E 25 m Methyl Silicone Cofumn Figure 7. Aldehyde Chromatography. QUALITY ASSURANCE--The Quality Assurance/Quality Control (OA/QC) Plan and Proce- dures include Organization and Responsibility, assigning QC responsibilities to program staff. Objectives for Figure 9. Ether Chromatography. Measurements and Performance establishing accuracy and precision goals for all program measurement sys- tems, Outputs providing both the outputs which are necessary to assure that equipment is properly main- B.ack Pace 7 ------- tained, and outputs needed to assess and monitor QC, Statistical Methods describing how outputs, such as accuracy and precision, are to be calculated. Reports identifing all QC reporting requirements and milestones, and Audits describing system audit procedures, cal program at Research Triangle Park, N.C. is sup- ported by an onsite contract with ManTech Environmental Technology, Inc. QC/QA organization for this program provides overall project QA responsi- bility to the EPA Project Officer. All QC reports or outputs related to measurements performed by Man- Tech personnel are the responsibility of the ManTech Technical Supervisor. mance-The quality assurance objectives for accuracy and precision are presented in Table 5. If at any time it is noted that deviations in measured values exceed the objectives, testing is stopped, equipment is exam- ined, and testing is resumed after the prob" 3m has been corrected. Table 5. Quality Assurance Objectives. PARAMETER ACCURACY, % PRECISION, % THC Analysis 10 2 CO Analysis 10 2 N0X Analysis 10 2 CO2 Analysis 10 2 Alcohol Analy- sis 10 5 Ether Analysis 10 5 Aldehyde Anal- ysis 10 5 Detailed HC Analysis 10 5 Dyne Speed 5 5 Dyno Torque 5 R Reid Vapor Pressure 10 5 PDP Counter 10 5 SHED Volume 2 2 SHED Leak Rate 10 5 Gravimetric Balance 5 1 Gravimetric Weights 1 1 SHED Temper- ature 5 5 Dyno Cell Tem- perature 5 5 Veh. Coolant Temperature 5 5 Fuel Tempera- ture 5 5 Catalyst Tem- perature 10 10 CVS Tempera- ture 5 5 Dyno Cell Pres- sure 5 2 CVS Pressure 5 2 QC Procedures and Outputs-The QC outputs required for this program are given in Tables 6 and 7, All outputs should be completed within the specified periods for the duration of the program. Outputs given in Table 6 are "nondeliverable" which means that the QC work, when completed, is signed off in the QC Notebook with no other report required. The Project Officer reviews all QC Notebooks monthly insuring that all equipment is being properly maintained and quality controlled. Outputs given in Table 7 are reported directly to the Project Officer since these indicate the status of compliance with the data specifications stated in the previous section. Table 6. QC Nondeliverable Outputs. OUTPUTS 1 TIME PERIOD Calibrate THC An- alyzer (86.121-82,90) Daily Adjust THC FID for op- timum HC response (86.121-82! Annually THC Analyzer linearity checks (86.121-82,90) Monthly THC Analyzer MeOH response (86.1 21 -90) Monthly Black Page 8 ------- Calibrate CO Analyzer (86.122-78) Daily CO Analyzer H2O inter- ference check (86.122- 78) Annually CO Analyzer linearity check (86.122-78) Monthly Calibrate NOx An- alyzer (86.123-78) Daily NOx Analyzer con- verter efficiency check (86.123-78) Weekly NOx Analyzer linearity check (86.123-78) Monthly Calibrate CO2 An- alyzer (86.124-78) Daily CO2 Analyzer linearity check Monthly Calibrate CVS (86,119- 78,90) Semi-annually Calibrate temperature transducers (ASTM E220-80) Monthly Calibrate pressure transducers (CVS Pro- tocol) Monthly Calibrate dry test me- ters (86.120-82) Monthly Verify currency of NBS cylinder certifi- cates Monthly Calibrate dyno speed signal (EPA 650/4-75- 024d, TP 202) Monthly Calibrate dyno load cell (86.118-78 & manuf. recommenda- tions) Monthly Calibrate weights I ASTM E617-81) Quarterly Calibrate RVP (80.Ap- pendix D, ASTM D323- 89) Monthly Calibrate GCs (GC RPM) Daily Calibrate HPLC (Alde- hyde RPM) Daily Calibrate SHED (86.117-78,90) Annually Characterize SHED leak rate (86.117- 78,90) Monthly Perform dyno preventa- tive maintenance As Scheduled Perform SHED preven- tative maintenance As Scheduled Oxygenate methods cross-checks Monthly Detailed HC methods cross-checks Monthly Calibrate Ether an- alyzer (80-Appendix F) Daily 1 numbers in parenthesis are Federal Register refer- ences unless otherwise indicated Table 7. QC Deliverable Outputs. OUTPUTS 1 TIME PERIODS THC Analysis Monthly CO Analysis Monthly NOx Analysis Monthly CO2 Analysis Monthly Methanol Analysis Monthly Aldehyde Analysis Monthly Detailed HC Analysis Monthly Ether Analysis Monthly Dyno Speed Monthly Dyno Torque Monthly SHED Temperature Monthly Cell Temperature Monthly Coolant Temperature Monthly Fuel Temperature Monthly Catalyst Temperature Monthly CVS Temperature Monthly SHED Pressure Monthly Cell Pressure Monthly Black Page 9 ------- CVS Pressure Monthly SHED Volume (and in- tegrity) Monthly Balance Monthly Reid Vapor Pressure Monthly PDP Counter Monthly HC Blind Audit Results Quarterly CO Blind Audit Results Quarterly NOx Blind Audit Re- sults Quarterly CO2 Blind Audit Re- sults Quarterly Gravimetric Weights Annually QC Notebook Monthly 1 measures of precision and accuracy unless otherwise indicated Accuracy and precision for most of the parame- ters listed in Table 5 are determined using "blind" samples which have been referenced to the National Institute of Standards and Technology (NIST). Because NIST standards are not available for detailed HC and aldehyde measurements, research protocol methods (RPMs) are used to assure the accuracy and precision of these measurements. Any parameter which fails to achieve its specified accuracy or precision goal shall be corrected before testing can proceed. Data whose integrity has been compromised due to the malfunctioning of any instru- ment or system during its collection shall be discarded and the tests rerun. For this reason, the Project Officer reviews all data being generated daily and ceases testing when trends reveal the likelihood of some com- ponent malfunction or other system irregularity. QC Statistical Methods-All accuracy determina- tions (except for SHED Volume) are made by comparing the mean measured value from three separate measure- ments of the reference material with the actual value of the reference material according to equation 5: determining accuracy and precision. All reference ma- terials are NIST, directly referenced to NIST, or prepared in accordance with an accepted Standard Operating Procedure (SOP) when NIST standards are not available. Measures of accuracy and precision involve pollutant concentrations, temperatures, and pressures near the median values experienced in the empirical program. Accuracy of the SHED volume is assured in accordance with standard practice (1). Precision is calculated by taking the standard deviation (SD) of ten measurements for emissions an- alyzers and three for all other devices, and dividing it by the mean value (MV) according to equation 6: SD % Precision = —— x 100 (6) MV Reports-Routine "deliverable" outputs (Table 7) are reported to the Project Officer in accordance with the QC procedures and outputs section; and other outputs entered :n a QC Notebook which is presented monthly to the Project Officer as a "deliverable" output. The Project Officer makes a QC Evaluation Report quart >y and within the Final Report. The Evaluation Report is a brief summary of QA/OC within the project and is meant to highlight problem areas, their resolution or nonresolution, and recommended action to be taken in the event of unresolved issues. Audits—An annual systems audit of the project is conducted by the MSERB QA Officer and/or the Branch Chief. The systems audit focuses on the project's adherence to required procedures. For example, instru- ment logs or notebooks are checked to see if the equipment is being properly maintained and calibrated, procedures for determining accuracy and precision are discussed with personnei who actually perform these measures, and QA equipment, such as calibration gases and meters, are examined for documented certification. Instrument operators are questioned about the daily or routine procedures they follow when running a test. Particular attention is directed to insuring that SOPs and RPMs are being followed. As deficiencies are noted, the person responsible is instructed to insure that immediate corrective action is taken. MV-RV % Accuracy = ——— x 100 (5) n v where MV - RV = absolute magnitude of mean value minus reference value. The reference material is presented to the analyzer operator as an "unknown"; span gases are not used for TECHNICAL APPROACH - ATMOSPHERIC CHEMISTRY Comprehensive evaluation of the impact of alter- native fuels on risk to public health and welfare must include examination of the atmospheric chemistry of the emissions. The formation of photochemical oxi- Black Page 1 0 ------- dants in urban environments including ozone, results from chain reactions involving hydrocarbons and oxides of nitrogen (NOx) in the presence of sunlight. These reactions produce many organic compounds, including aldehydes and ketones, peroxyacetyl nitrate (PAN), organic nitrates and peroxides, and others. Some of the products have different genotoxic (i.e., mutagenic or possibly carcinogenic) properties than the reactant compounds, that is, the original emissions. ManTech Environmental Technology has devel- oped experimental protocols permitting the direct study of the atmospheric chemistry of motor vehicle emis- sions, including the formation of ozone, and toxic and mutagenic compounds (11). The protocols involve irradiation of mixtures of motor vehicle tailpipe exhaust (generated by prescribed driving cycles) and surrogates of evaporative emissions or background urban air or- ganic compound mixtures. The surrogate addition is necessary to achieve HC/NOx ratios typical of urban air mixtures. Automobile emissions typically have HC/NOx ratios of about I to 3, whereas urban atmospheres have ratios in the 7 to 1 2 range. The formation of ozone and other toxic chemicals is sensitive to this ratio. At the lower ratios (i.e., 1 - 3), atmospheric chemistry pro- ceeds extremely slowly. In these studies, continuous measurements are made of the major inorganic chemical species present in the chamber, which include NO, NOx, O3, and CO. The total hydrocarbon signal is also measured continu- ously. Hydrocarbons in the mixture are speciated by gas chromatography using two columns (DB1 and Car- bowax) in series. This GC is also capable of measuring numerous reaction products following irradiation includ- ing organic nitrates and nitro compounds. PAN and other peroxyacyl nitrates are measured using a dedi- cated GC having a packed carbowax column and elec- tron capture detection. Carbonyl compounds are sampled by impinger collection through DNPH derivatiz- ing agent and quantified by HPLC. Nitric acid can also be formed through photochemical reactions and is measured by collection on nylon filters and analysis by ion chromatography. These measurements are made before irradiation and periodically during the progress of the photochemical reaction. During 1992, ManTech will construct and char- acterize an irradiation chamber facility interfaced with a motor vehicle similar to that illustrated in Figure 10. In the experiments for this study, the chamber design will be portable permitting both indoor irradiations with UV-A and UV-B blacklights, and outdoor irradiations with actual sunlight. The design uses two identical 8,000 L chambers permitting contrasts between the reaction products of the motor vehicle exhaust mixtures and reference mixtures. The initially conceived design allows the chamber to be operated with or without dilution, depending on the objectives of individual ex- periments. The chamber will be characterized by irra- diating mixtures of single hydrocarbons and NOx , which have well-studied profiles of reactant disappear- ance and product formation. Following construction and characterization of the chamber facility, an extensive three-phase testing program will be initiated examining the atmospheric chemistry of emissions from the previously described vehicles and fuels. In most experiments, direct com- parisons will be made of the oxidant and/or toxic compound(s) formation, by comparison of the irradiated reference and the test mixtures. The major two phases include: oxidant formation studies and detailed chemi- cal characterization of the photooxidation products. In an optional third phase, characterization of the mutage- nicity of the reactants and products can be made using Ames bioassays by procedures already developed. REFERENCES 1. Code of Federal Regulations, Title 40, Part 86, Control of Air Pollution from New Motor Vehicle and New Motor Vehicle Engines: Certification and Test Procedures, Office of the Federal Register National Archives and Records Administration, Washington, D.C., July, 1990. 2. Burns, V.R., Bensen, J.D., "Description of Auto/Oil Air Quality Improvement Research Program," SAE 912320, International Fuels and Lubs Meeting, Toronto, Canada, October, 1991. 3. Baugh, J., Ray, W., Black, F., Snow, R., "Motor Vehicle Emissions Under Reduced Temperature Idle Conditions", Atmos. Env., Vol. 21 (10), pp 2077-2082 (1987). 4. Sigoby, J.E., McArver, A., Snow, R., "Evalua- tion of a FTIR Mobile Source Measurement System," EPA/600/S3-89/036, U.S. Environmental Protection Agency, Research Triangle Park, NC, August, 1989. 5. Gabele, P.A., Baugh, J.O., Black, F.M., Snow, R., "Characterization of Emissions Using Methanol-Gas- oline Blended Fuels," JAPCA, Vol. 35, pp. 1168-1175 (1985). 6. Sigsby, J.E., Duncan, J., Crews, W., Burton, C., "Research Protocol Method for Analysis of Detailed Hydrocarbons Emitted from Automobiles by Gas Chro- Black Page 11 ------- Ambient air Exhaust Compressor Air 3.2 cm Teflon Tubing Dilution Tunnel 20 m /min Turbine Dynamometer Clean Air Generator Flow mete: Nitrogen Panicle Filter Inlet Manifold 150 L Dewar 273 K Evaporative Surrogate 60-65 L/min Filter I i I Effluent Exposure Chamber Clean Air Exposure Chamber 1 40 L Reactants Exposure Chamber 140 L Reaction Chamber Carryover Exposure Chamber 140 L 140 L 8,000 L Samples ~ 14 Umin y 14 L/min Teflon 14 L/min Effluent Exposure Chamber Reaction Chamber 8,000 L Carryover Exposure Chamber 140 L Samples 140 L 14 L/min Y Figure 10. Schematic of Test Apparatus for Examining the Photochemical Oxidant and Toxic Compound Products from Irradiated Automobile Exhaust Mixtures. Frank Black Page 12 ------- matography," U.S. Environmental Protection Agency, Research Triangle Park, NC, June 1989. 7. Tejada, S.B., "Evaluation of Silica Gel Car- tridges Coated In Situ with Acidified 2,4- Dinitrophenylhydrazine for Sampling Aldehydes and Ketones in Air", Intern. J. Environmental Anal. Chem., Vol. 26, pp 167-185 (1986). 8. U.S.EPA, "Calculation of Emissions and Fuel Economy When Using Alternative Fuels - Appendix A-5: Measurement of Methanol," EPA 460/3-83-009, Office of Mobi'e Sources, Ann Arbor, Ml, March, 1983 9. Federal Register, "Test Method for Determina- tion of C1 to C4 Alcohols and MTBE in Gasoline by Gas Chromatography," Vol. 54(54), pp 11904-11 91 U, March 22, 1989. 10. Duncan, J.W., Burton, C.D., Crews, W.S., "A Method for Measurement of Methanol, Ethanol, and Methyltertiarybutyl Ether Emissions from Motor Vehi- cles," Northrop Services, Inc., Research Triangle Park, NC, 1988. 11. Kleindienst, T.E., Smith, D.F., Hudgens, E.E., Snow, R.F., Perry, E., Bufalini, J.J., Claxton, L.D., Black, F.M., Cupitt, L.T., "The photooxidation of au- tomotbile emissions: measurements of the transforma- tion products and their mutagenic activity," In Review, Atmos. Environ., (1991). The information presented in this document has in part been funded by the United States Environmental Protection Agency. It has been subjected to the Agency's peer and adminisrtative review, and has been approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. ------- |