Presentation on theme: "Ozone Formation from VOC Sources at New Haven, CT Kurt Kebschull State of Connecticut, Department of Energy and Environmental Protection."— Presentation transcript:
Ozone Formation from VOC Sources at New Haven, CT Kurt Kebschull State of Connecticut, Department of Energy and Environmental Protection
Introduction Research project: use PAMS data to make policy relevant conclusions about source-specific emission reduction programs Recent OTC sensitivity modeling emphasizes the need to find local emission reductions to meet increasingly tighter ozone standards CT DEEP runs 3 PAMS monitors at East Hartford (class 2 - max conc.), New Haven (class 2), and Westport (class 1 – max downwind )
New Haven, CT (industrialized port city) Highways and Stationary Source Locations MONITOR GAS TANKS Metal finishing PSE&G peaking generating station
What is the emissions profile of New Haven city? Transportation hub- planes, trains, and automobiles (many trucks) Nearly a million people in New Haven MSA (cars, consumer products) Industry (metal finishing, plastics manufacturing (solvents)) Fuel terminal/transfer (evaporating gasoline) Power generation (new generation peaking) http://www.pseg.com/family/power/fossil/stations/connecticut/newhaven_peaker.jsp http://www.pseg.com/family/power/fossil/stations/connecticut/newhaven_peaker.jsp
Timing of emissions/formation: Diurnal Variation on ozone and precursors at New Haven, CT during an ozone event -Diurnal patterns show meteorology, chemistry and emissions all play a role in variation -Source emissions timing-a maximum for motor vehicles i.e. AM, PM rush hour (NOx red line) -TNMOC, NOx are anti-correlated w/ozone -Questions: How fast is ozone forming photochemically as TNMOC, NOx drop? -If it’s the lifting inversion diluting the TNMOC/NOx, where is the ozone being formed? -If being formed aloft and mixing down, isn’t the NOx being diluted too fast?
What sources indicated by PAMS are the most abundant? What does this say? -PERCENTAGES ARE BASED ON MARKER SPECIES (C-refers to the # of carbon atoms, e.g. C5s are pentanes, suffix -ane means alkane = paraffin PAR; alkene=olefin OLE, model splits aromatics TOL-toluene, XYL-xylene, most benzenes are relatively inert w/r/t O3 formation -(C4,5), (C5) are evaporating gasoline profiles (cars and gas stations and gasoline storage tanks- contributing 47% -(C8-12) diesel combustion; MVCAR (light alkanes, alkenes, aromatics) ; (C2,3) aged combustion: contributions to on-road, off road mobile, 123 TB (trimethylbenzene-ethanol blend gasoline evaporation or combustion - 40% contribution. Total 87% is related to mobile sources and combustion -Biogenic- 3% lowest of all PAMS sites (see satellite imagery) -VOC in New Haven are the highest of all PAMS sites in OTR. (due to monitor placement) -Styrene profile-includes many industrial solvents (aromatics-few alkanes) -10% contribution -VOCs in many consumer products/solvents & degreasers species are not in PAMS (i.e. ethanol, mineral spirits)
What sources contain the most reactive species? 10 most abundant VOCs at New Haven 10 most reactive VOCs at New Haven ozone formation potential The most abundant are seldom the most reactive. Low concentration species make more ozone (except iso- pentane and toluene). Six of the top ten reactive compounds (OLEs) can be attributed to MV combustion.
COMPARISON OF 3 CT SITES- most reactive species in boxes, end in “e”- note logarithmic scale
NHDES modeling shows modest benefit to VOC reductions, but downwind (not in)of the target box. Greenwich, CT is a part of the NYC box. Long Island Sound appears to magnify the ozone reductions- few VOC sources over the water, most VOC from inland.
Top categories of the NY box (2008 NEI)… where do you reduce 30 tons-total 820 tons/day? How do you cut by 50% categorytpdpct Mobile - Aircraft2.7133550.330391 Mobile - Commercial Marine Vessels3.4938950.425433 Mobile - Non-Road Equipment - Other4.1356790.50358 Industrial Processes - Storage and Transfer4.8490650.590446 Mobile - On-Road Diesel Heavy Duty Vehicles7.7910520.948676 Industrial Processes - NEC9.5157631.158685 Mobile - Non-Road Equipment - Diesel9.5360441.161155 Solvent - Graphic Arts10.675141.299856 Solvent - Dry Cleaning11.556971.407233 Bulk Gasoline Terminals14.326141.74442 Fuel Comb - Residential - Wood14.778021.799443 Waste Disposal19.157642.332727 Miscellaneous Non-Industrial NEC26.471583.223307 Gas Stations26.751613.257405 Biogenics - Vegetation and soil44.737895.447502 Solvent - Non-Industrial Surface Coating47.031665.726802 Solvent - Industrial Surface Coating & Solvent Use65.464937.971326 Solvent - Degreasing66.607288.110424 Solvent - Consumer & Commercial Solvent Use138.492916.86356 Mobile - On-Road Gasoline Light Duty Vehicles139.531816.99007 Mobile - Non-Road Equipment - Gasoline142.165717.31078
UMD modeling: a large VOC cut yields about 2-4? ppb O3 benefit - not insignificant. However, NOx cuts are far more beneficial.
A COMPARISON OF OFP BY VARIOUS VOC SOURCES-OTC STRATEGIES
Using the speciation-MIR (g of O3 formed/ g of VOC emitted)/ methodology to evaluate OTC reduction strategies OTC strategy: consumer products, 9,728 tpy reduction, most species not detectable by PAMS. OFP= 8,093tpy. Most abundant species are not highly reactive, i.e. ethanol.
Using the speciation-MIR methodology to evaluate OTC reduction strategies OTC strategy: large tank farm gasoline, 2,055 tpy. The cost/benefit ratio magnitude led the OTC ADs not to pursue this strategy? OFP=1,842tpy.. Most abundant species are not highly reactive, i.e. PARs.
Using the speciation-MIR methodology to evaluate OTC reduction strategies OTC strategy Solvents and Degreasers: 32,485 tpy reduced- I’m not sure what profile SMOKE uses for this category. OFP= 28,806tpy- too much, 52% not id’d. Most abundant species are not highly reactive, i.e. heavy PARs
EXAMPLES OF PARTICULAR SOURCES ALREADY BEING CONTROLLED
Gas station emissions (2008 NEI for OTC states) Stage II has a 95% control efficiency- 0.05*77,687(nei estimate for gas stations)~4000 tpy emitted if operating as designed. Not as many highly reactive compounds here. OFP~4500. Stage II controls are being phased out Benefit above Stage II is yet to be determined.. Most abundant species are not highly reactive, i.e. C4,5 PARs, butanes, pentanes.
Light duty vehicles. 2008 NEI emissions for OTC states PollutantPercentTPYmirOZONE FORMATION POTENTIAL ETHYLENE8.94581068.76357157.7269 ISOPENTANE8.94581061.3655449.14481 TOLUENE8.784581063.88156060.2071 OTHER6.594581060 M/p-XYLENE6.54581067.33218264.5823 BENZENE5.674581060.6917922.47928 PROPYLENE3.5645810611.37185428.4637 N-PENTANE3.354581060.467059.412769 1,2,4-TRIMETHYLBENZENE3.274581068.64129427.7593 1-BUTENE3.234581069.42139386.0665 N-BUTANE3.14581061.0815337.38738 NEI 2008 light duty gasoline vehicles emissions=458,106 TPY. Total OFP=1,873,579TPY. 6-10 of the top species highly reactive for ozone (cars create more ozone/g of VOC). ~ 4X more reactive than consumer products & solvents and degreasers.. Most abundant species are highly reactive, i.e. OLEs, AROMATICS
Heavy-duty diesels, 2008 NEI emissions for OTC states 2008 NEI HDD OTR emissions = 33,490 TPY. Total OFP= 133,405 TPY, 6 of the top 10 compound are moderate-highly reactive for ozone.. Most abundant species are highly reactive, i.e. OLE, AROMATICS
Both VOC and NOx from onroad vehicles are expected to drop by 2/3 from 2007-2020 (MARAMA inventory report)
SUMMARY When adopting VOC reduction, the reactivity of the species should be considered Not all VOCs are created equal-unlike NO Domestic/industrial VOC sources appear to pale in comparison to mobile sources w/r/t ozone formation Densely populated cities like NYC have more emissions of consumer products /solvents per capita than LDGV combustion Getting 50% VOC reductions from other than mobile sources would be difficult (OTC measures reduce only 32,000 of 600,00 tpy (7%)) 50% (anthropogenic) VOC reductions do not seem to give large reductions in ozone. NOx reductions ABOVE FMVCP, might require fuel changes, HEDD regulations on hot days and NOx controls on upwind EGUs Reductions of 30 tpd in the boxes looks doable