PM Emissions Characteristics of APUs burning Conventional and Alternative Fuels

Size: px

Start display at page:

Download "PM Emissions Characteristics of APUs burning Conventional and Alternative Fuels"

Brett Lloyd
5 years ago
Views:

1 PM Emissions Characteristics of APUs burning Conventional and Alternative Fuels P. Lobo, P.D. Whitefield, D. Hagen, C. Wilson, L. Rye and P. Williams Cambridge Particle Meeting Cambridge, UK May 21, 2010

The rising cost of oil coupled with the need to reduce pollution and dependence on foreign suppliers has spurred great interest and activity in developing alternative aviation fuels.

those of conventional aviation fuel types.

2 The rising cost of oil coupled with the need to reduce pollution and dependence on foreign suppliers has spurred great interest and activity in developing alternative aviation fuels. The objectives of the APU studies were to work with the aviation community to gather accurate data on emissions from candidate alternative fuels and to compare these emission characteristics with those of conventional aviation fuel types. These data will provide the essential information for the aviation community at large as it charts a course for environmental sustainability in an uncertain energy future. Motivation Fuel costs are now the largest expense in civil aviation increasing and Center fluctuating of Excellence prices for Aerospace are causing Particulate an economic Emissions crisis Reduction in the industry Research

3 Objectives Long-term Provide comprehensive data on the impact of candidate alternate fuels on PM emissions from engines currently operating in the commercial fleet. These are critical data for the Commercial Aviation Alternate Fuels Initiative (CAAFI) stakeholders. Near term Characterize PM emissions from APUs Examine and, where possible, quantify any changes in PM emissions from engines burning alternative fuels and blends compared to conventional JET A, JET A1, and JP-8 fuels SAE E31 Aerospace Recommended Practice for Aircraft Non-Volatile PM APUs as small scale gas turbine engines provide an ideal test bed for PM emissions measurement methods development

4 Venue: AAFEX NASA Dryden Aircraft Operation Facility, Palmdale, CA Dates: January 20 February 03, 2009 Participants: NASA AEDC EPA Aerodyne Research Inc Air Force Research Lab at WPAFB United Technologies Research Center Missouri University of Science and Technology

AAFEX APU: Honeywell (formerly Garrett) Model GTCP85-98CK Single-stage radial inflow turbine Mounted cross-wise in a forward baggage compartment of the DC-8 DC-8 was not supplied with an APU as

5 AAFEX APU: Honeywell (formerly Garrett) Model GTCP85-98CK Single-stage radial inflow turbine Mounted cross-wise in a forward baggage compartment of the DC-8 DC-8 was not supplied with an APU as original equipment Fuels: JP-8 (Conventional Jet Fuel) ctl (Fischer-Tropsch Fuel from Coal) Fuel Symbol C Fraction H/C Ratio Sulfur Aromatics Naphthalenes Olefins wt/wt mol/mol ppm vol% vol% vol% Base fuel JP Coal-derived Fischer-Tropsch FT fuel a a. Product of SASOL, South Africa

6 PM Emissions Measurements PM emissions were measured Range of APU conditions from minimum load (cockpit power) to maximum load (full air conditioning and bleed air) The PM sampling instrumentation suite included a Cambustion DMS500 fast particle size spectrometer

7 PM Size Dist. Shape Parameters (DMS500) Number-based Geometric Mean Diameter (Dgn) vs. EGT JP-8 Jan 29 FT-2 Feb 02 Dgn (nm) EGT ( 0 C) Dgm (nm) Mass-based Geometric Mean Diameter (Dgm) vs. EGT JP-8 Jan 29 FT-2 Feb EGT ( 0 C)

8 PM Emission Indices (DMS500) 9.0E E+15 Number-based Emission Index (Eln) vs. EGT Eln (#/kg fuel) 7.0E E E E E+15 JP-8 Jan 29 FT-2 Feb E E E EGT ( 0 C) Elm (g/kg fuel) Mass-based Emission Index (Elm) vs. EGT JP-8 Jan 29 FT-2 Feb EGT ( 0 C)

9 Black Carbon Emission Index (MAAP) Black Carbon Emission Index (mg/kg fuel) Aerodyne JP-8 Aerodyne FT-2 NASA JP-8 NASA FT Exhaust Gas Temperature ( o C)

10 NOx Emission Index NOx Emission Index (g/kg fuel) NASA FT-2 NASA JP-8 Aerodyne JP-8 Aerodyne FT Exhaust Gas Temperature ( o C)

11 SO 2 Emission Index SO2 Emission Index (g/kg fuel) NASA JP-8 NASA FT-2 EPA JP-8 EPA FT Exhaust Gas Temperature ( o C)

12 PAH Emission Index EPA PAH Emission Indices 3000 PAH Emission Index (ug/kg fuel) JP-8 FT Exhaust Gas Temperature ( o C)

13 AAFEX Summary APU gas and PM emissions decreased with increasing engine power as indicated by exhaust gas temperature. For JP-8, EIn and EIm respectively dropped from ~5 x kg -1 and ~500 mg kg -1 at minimum load (cockpit power) to kg -1 and 200 mg kg -1 at maximum load (full air conditioning and bleed air). Burning FT-2 fuel APU did not significantly effect APU NOx emissions Compared to JP-8, FT-2 fuel drastically reduced the APU s PM emissions. Average EIn and EIm values were respectively factors of 6 and 13 lower when burning the alternative fuel. APU FT-2 nonvolatile PM emissions were smaller compared JP-8 emissions.

14 Sheffield APU Study Venue: University of Sheffield Low Carbon Combustion Centre, Beighton, S20 1AH, UK Dates: September 21 - October 01, 2009 Participants: University of Sheffield University of Leeds University of Manchester/ Manchester Metropolitan University Missouri University of Science and Technology

Sheffield APU Study APU: Recommissioned Artouste Mk113 APU Single spool gas turbine engine Used on RAF Victor Bomber Supplied air for engine starting and electrical power to the

15 Sheffield APU Study APU: Recommissioned Artouste Mk113 APU Single spool gas turbine engine Used on RAF Victor Bomber Supplied air for engine starting and electrical power to the aircraft systems Fuels: JET A1 (Conventional Jet Fuel) ctl (Fischer-Tropsch Fuel from Coal) gtl (Fischer-Tropsch Fuel from Natural Gas) 50:50 gtl-jet A1 blend Biodiesel (FAME) Diesel

PM Emissions Measurements PM emissions were measured Two APU conditions: idle and full power Three sampling locations: Exit plane with dilution at probe tip Exit plane with dilution 1m downstream of

16 PM Emissions Measurements PM emissions were measured Two APU conditions: idle and full power Three sampling locations: Exit plane with dilution at probe tip Exit plane with dilution 1m downstream of probe tip 10m from the exit plane The PM sampling instrumentation suite included two Cambustion DMS500 fast particle size spectrometers A thermal discriminator operating at 300 C was used to remove volatiles from the exhaust samples to one of the DMS500s Three main measurement objectives: Investigate effects of probe tip vs. downstream dilution Investigate emissions characteristics of alternative fuels Investigate plume evolution effects

17 Probe tip vs. Downstream dilution (SAE E31) 6.00E+08 JET A1 Size Distributions (Total and NV) - Dilution introduced at the probe tip Idle - NV dn/dlogdp 5.00E E E E+08 Full power- NV Idle - Total Full powertotal 1.00E E E E+08 Dp (nm) 1.60E E+08 JET A1 Size Distributions (Total and NV) - Dilution introduced 2m from probe tip Idle Full power dn/dlogdp 1.20E E E E+07 Idle - NV Full power- NV 4.00E E E Dp (nm)

18 Probe tip vs. Downstream dilution (SAE E31) NV PM Number based Emission Index (#/kg Fuel) Fuel: JET A1 3.0E E E E E E E+00 Probe 1 Probe 2 Idle Full power Probe 1: Dilution at probe tip Probe 2: Dilution at 1m downstream of probe tip NV PM Mass based Emission Index (g/kg Fuel) Fuel: JET A Probe 1 Probe 2 Idle Full power

19 Probe tip vs. Downstream dilution (SAE E31) dn/dlogdp 6.00E E E E E E+08 JET A1 Size Distributions (Total) Probe 1 vs. Probe 2 Probe tip Dil 1m dil TOTAL PM Idle - Total - Probe 1 Full power- Total - Probe 1 Idle - Total- Probe 2 Full power -Total - Probe 2 SAE E31 Sampling methods Issues: Probe tip vs downstream dilution (1m) Difference in distributions due to agglomeration of PM (<20nm) prior to dilution in the downstream case. dn/dlogdp 0.00E E E E E E E Dp (nm) JET A1 Size Distributions (NV) Probe 1 vs. Probe 2 Probe tip Dil 1m dil Non V. PM Idle - NV - Probe 1 Full power- NV - Probe 1 Idle - NV - Probe 2 Full power-nv - Probe 2 Since it appears in total and nonvolatile distributions the agglomerating PM are not volatile PM. Statistically significant differences are observed in the number-based EI s measured in the two sampling regimes but no statistically significant differences are observed in the mass-based EI s 0.00E Dp (nm)

20 Fuel Comparison (Probe tip dil) dn/dlogdp 6.00E E E E E E+09 Biodiesel Size Distributions (Total and NV) Dilution introduced at the probe tip Idle - Total Full Power - Total Idle - NV Full Power- NV 6.00E E+09 Fuel Total PM Non volatile PM Mass Conc Num. Conc Mass Conc Num. Conc mg/m3 #/cm3 mg/m3 #/cm3 Bio diesel 9.20E E E E+08 Jet A1 3.00E E E E+07 gtl 2.50E E E E+07 JET A1 Size Distributions (Total and NV) Dilution introduced at the probe tip Idle - NV Full power- NV 0.00E Dp (nm) dn/dlogdp 4.00E E E E E+00 PM emissions studies on a series of alternative fuel candidates: gtl and bio-diesel with Jet A1 as the baseline fuel for emissions comparison Dp (nm) Idle - Total Full power-total dn/dlogdp 6.00E E E E E E E+00 gtl Size Distributions (Total and NV) Dilution introduced at the probe tip Dp (nm) Idle - NV Full power- NV Idle - Total Full power-total

21 Idle Full power Probe tip Dilution - Number 1.2 JET A1 Biodiesel Idle Full power 0 JET A1 Biodiesel Total PM Number Concentration normalized to JET A1 NV PM Number Concentration normalized to JET A Idle Full power Probe tip Dilution - Mass 4.5 JET A1 Biodiesel Idle Full power JET A1 Biodiesel Total PM Mass Concentration normalized to JET A1 NV PM Mass Concentration normalized to JET A1

22 AMS Data Idle Bio Diesel Jet A1 Full power Bio Diesel Jet A1 AMS Data provided by Paul Williams (The University of Manchester)

23 Smoke Number Data Smoke Number Data provided by Chris Wilson (The University of Sheffield)

24 JET A1 Biodiesel Comparison Increases in total PM at idle and full power for bio-diesel are observed when compared to jet A1 This is due to gas-to-particle conversion in the unheated sample line as evidenced by the differences in the total and non-volatile size distributions. The AMS data indicates that the condensable material is organic in composition. This condensable material is volatile at 300 o C (the discriminator set point) This organic material has a strong propensity to condense as evidenced by its condensation despite probe tip dilutions typically >20:1 It is reasonable to assume that such condensation would occur with natural dilution and cooling in the atmosphere. The reduction in PM observed in the non-volatile samples is consistent with the results from filter sample analysis for exhaust ducted through heated sample lines (150 o C) to the filters (smoke meter measurements).

25 Non-volatile PM Emissions data Non volatile PM Number concentration normalized to JET A Idle Full power JET A1 gtl 50 gtl : 50JETA1 Biodiesel Non volatile PM Mass concentration normalized to JET A JET A1 gtl 50 gtl : 50JETA1 Biodiesel 0 Idle Full power

26 Next Steps APU Emissions Emissions Characterization of modern commercial APUs Alternative Fuels Emissions Characteristics of gas turbine engines burning Biofuels (AAFFEX II) SAE E31 Resolve sampling, mass and number issues to complete ARP by Dec 2011

27 Acknowledgements AAFEX team, and NASA DC-8 personnel NASA, ARI and EPA for use of their data Sheffield APU study team The Universities of Manchester and Sheffield This work was funded by the FAA through the Partnership for AiR Transportation for Noise and Emissions Reduction (PARTNER) - a FAA-Transport Canada (TC)- NASA-sponsored Center of Excellence under FAA Award Nos.: 07-C-NE-UMR Amendment Nos. 006, 007 and 009 Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the FAA, NASA, or Transport Canada

SAE E31 Methodology Development and Associated PM Emissions Characteristics of Aircraft APUs burning Conventional and Alternative Aviation Fuels

Partnership for AiR Transportation Noise and Emissions Reduction An FAA/NASA/Transport Canadasponsored Center of Excellence SAE E31 Methodology Development and Associated PM Emissions Characteristics of