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Conclusion

VIEWS: 101 PAGES: 34

									Summary (I)                                                                                                  1
                                                                                Swed Gov’t cost ben 970203


The proposed levels of sulphur in EU petrol for 2000 will make it
difficult to further reduce automobile emissions with currently
available technologies


Sulphur has a negative effect on the performance of 3-way catalytic
converters and thereby increases the emissions of CO, HC
(hydrocarbons) and NOx from petrol driven automobiles - however,
the catalytic converter returns to full efficiency if sulphur content is
subsequently reduced

The proposed standard of 200 ppm sulphur in petrol will:
         inhibit the introduction of currently available gasoline direct injection (GDI)
          engines with systems for lean NOx reduction
                –   it has been reported that GDI engines can reduce petrol
                    consumption by up to 35%
                –   GDI engines have already been introduced in Japan because
                    current market levels of sulphur in petrol are less than 50 ppm
         significantly increase the emissions from vehicles which can meet
                                                                                                                 1
          California low and ultra low emission standards (LEV and ULEV) and
Summary (II)                                                                                               1
                                                                              Swed Gov’t cost ben 970203


The proposed standard of 350 ppm sulphur in diesel will inhibit the
introduction of technologies to reduce emissions from diesel driven
road transport



    The retro-fit of trucks/automobiles with currently available oxidation catalysts and
     filters can reduce CO and HC emissions by around 50-70% and Particle Matter
     (PM) emissions by over 90% - however, diesel with a sulphur content less than
     75 ppm is required
    The introduction of DeNOx catalysts under current development, which have the
     potential of reducing NOx emissions by at least 30%, presently require a diesel
     with a sulphur content less than 50ppm




                                                                                                               2
Summary (III)                                                                                          1
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On the short term, there are environmental and human health benefits
which can be gained if there is a further reduction of sulphur levels in
road transport fuels



    Reducing sulphur limits in petrol from 200 to 50 ppm will further reduce CO, HC
     and NOx emissions by around 3-5%

    Reducing sulphur limits in diesel from 350 to 50 ppm will further reduce PM
     emissions by 5-8 % from Heavy Duty Vehicles (HDV)


           According to estimates of unit economic damage(ECU per tonne
           emitted) derived in other EU studies, the cost benefit in terms of
         improved human health and reduced building damage are estimated
                        between 400 -700 million ECUs a year




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Sulphur’s Affect on Emissions - Automobiles (petrol)                                                                    2
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The Auto/Oil study concluded that sulphur influences HC, CO and NOx
emissions, but has no effect on CO2 emissions or fuel consumption


     The effects are linear and can be predicted well
     A reduction of sulphur from 382 to 18 ppm in petrol (Auto/Oil test fuels) reduced
      emissions over the composite test cycle (cold start, city and highway driving)
     HC 0.015 g/km or 8.6%
              CO    0.113 g/km or 9.0%
              NOx   0.019 g/km or 10%
     In an extra urban driving test cycle (warm catalyst) reductions were even larger,
      but there were larger vehicle to vehicle variations and a higher dependence on
      sulphur fuel content
     HC 0.015 g/km or 52%
              CO    0.067 g/km or 43%
              NOx   0.027 g/km or 20%


     Source:     Auto/Oil Programme: European Programme on Emissions, Fuels and Engine Technologies                         4
Sulphur’s Affect on Emissions - Automobiles (petrol)                                                                         2
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Sulphur fuel content effects emissions by decreasing catalyst
conversion efficiencies



    Sulphur competes for active surface area sites on the catalyst

    Palladium catalysts, which are more effective in removing HC and                                          less
     expensive, are more sensitive to sulphur fuel content

    Sulphur’s effect on catalytic efficiency is not permanent, the catalyst can return
     to near optimum levels once it is subjected to low sulphur fuels and higher
     temperatures (>700°C)

    There is contradictory evidence that sulphur increases the light-off temperature
     (i.e. the temperature at which the catalyst begins operating)




     Source:   Auto/Oil Programme: European Programme on Emissions, Fuels and Engine Technologies;
               Appendix: Sulphur in Fuels: Benefits of Sulphur Reduction; 3. Sulphur’s affect on catalyst performance
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Sulphur’s Affect on Emissions - Automobiles (petrol)                                     2
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The proposed sulphur and other specifications were derived after a
lengthy programme which was initiated in 1991




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Sulphur’s Affect on Emissions - Automobiles (petrol)                                                                          2
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Reductions in CO, HC and NOx emissions can be expected if sulphur
is reduced in petrol
          Calculated emission reductions of CO, HC and NOx from automobiles:
                                    Composite cycle




 *Base emissions were calculated using the composite emission model derived from the regression analysis in the
 Auto/Oil program and the proposed EU parameters for petrol.
 Changes in emissions were calculated using the sulphur regression equations derived in the composite test cycles.                7
Sulphur’s Affect on Emissions - Automobiles (petrol)                                                                          2
                                                                                                 Swed Gov’t cost ben 970203


The impact is greatest in the extra urban driving cycle since the
catalyst is warm
          Calculated emission reductions of CO, HC and NOx from automobiles:
                         Extra Urban Driving Sequence (EUDC)




  *Base emissions were calculated using the EUDC emission model derived from the regression analysis in the
  Auto/Oil program and the proposed EU parameters for petrol.
  Changes in emissions were calculated using the sulphur regression equations derived in the EUDC test cycles.                    8
Sulphur's Affect on Emissions - Trucks (Diesel)                                                                             2
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Auto/Oil synthesised existing data and the linear relationship between
sulphur content in diesel and PM emissions was determined




                                                                             sulphur fuel content ranged
                                                                              between 500 and 2000 ppm
                                                                             PM emissions ranged
                                                                              between 0.18 - 0.40 g/kWh
                                                                              for HDV
                                                                             several different type of
                                                                              engines
                                                                             assumed constant fuel
                                                                              consumption




 Source:    Auto/Oil Programme: European Programme on Emissions, Fuels and Engine Technologies;
            Appendix: Sulphur in Fuels: Benefits of Sulphur Reduction; 1. Auto/Oil and ACEA sulphur correction formulas
                                                                                                                                9
Sulphur’s Affect on Emissions - Trucks (Diesel)                                                                               2
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A recent draft report by ACEA* recommends that the Auto/Oil sulphur
correction formula for heavy engines should be modified



     The Auto/Oil correction formula is only suitable for the ranges in which data was
      analysed - PM levels between 0.15 and 0.4 g/kWh and sulphur fuel levels
      between 500 and 2000 ppm
     Current and proposed levels in the EU are outside the range studied in the
      Auto/Oil programme
            Since October, 1996, sulphur content in diesel is regulated to 500 ppm
            PM emissions from HDV are currently regulated to 0.15 g/kWh (EURO II)
     The ACEA report contends that
            the Auto/Oil correction formula is not accurate enough to predict the
             influence of sulphur fuel content of 10 to 500 ppm on particulate levels
             between 0.05 and 0.15 g/kWh
            differences in fuel consumption need to be considered when correcting for
             nominal sulphur fuel content
*Influence of Diesel Fuel Quality on Heavy Duty Diesel Engine Emissions, Draft Report, European Automobile
Manufacturers Association                                                                                                         10
Sulphur’s Affect on Emissions - Trucks (Diesel)                                                               2
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ACEA has developed a more accurate HDV sulphur correction formula to be
used at sulphur levels below 500 ppm and PM emissions below 0.15 g/kWh




                Particulate  Cycle weighted        Sulphur to       Sulphur content
               emissions at brake specific fuel     sulphate            of fuels
                 S1 level     consumption       conversion factor        (ppm)
                 (g/kWh)        (g/kWh)




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Sulphur’s Affect on Emissions - Trucks (Diesel)                                                                  2
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Estimates of PM reductions from HDV can vary significantly between the
two models
                 Correction of PM emissions to sulphur content in diesel
                              (BSFC = 270 g/kWh; PM = 0.10 g/kWh)

                       PM2 - Auto/Oil sulphur correction formula




           9% reduction in
           PM emissions
            S2 = 10 ppm                     PM2 - ACEA sulphur correction formula                            PM2
                                                                                                           (g/kWh)


           25% reduction in
            PM emissions
             S2 = 10 ppm




                                             S1 - S2 (ppm)
                                                                                                                     12
Sulphur’s Affect on Emissions - Trucks (Diesel)                                                       2
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Using the ACEA sulphur correction formula indicates that a 2-3 times larger
reduction in particle emissions can be expected by reducing sulphur levels


                 Estimations of particle emission reductions using the
                   Auto/Oil and ACEA sulphur correction equations
                        (BSFC = 200 - 270 g/kWh; PM = 0.10 g/kWh)




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Sulphur’s Affect on Emissions - Trucks (Diesel)                                                   2
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The application of the ACEA sulphur correction formula suggests a greater
degree of freedom for certain engines in the NOx “Trade off”curves


  NOx                                             ILLUSTRATIVE
(g/kWh)




                                                              Fuel1
                                                              Fuel2 - Auto/Oil
                                                              Fuel2 - ACEA

                                                   Fuel Consumption, CO2 , PM
                                                            (g/kWh)
                                                                                                      14
New Technologies in Engine Design and Pollution Abatement Devices                                        3
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It is the automotive and catalyst producers’ opinion that sulphur
content greater than 50 ppm in both petrol and diesel inhibits the
implementation of new technologies




                                             Technologies Reportedly Inhibited by Sulphur in Fuels



                                                   Gasoline Direct Injection (GDI) engine technolo
                                                   Lean NOx or (DeNOx) catalysts for GDI and die
                                                   Continuous Regenerating Trap (CRT) for HDV e
                                                   Filters and/or oxidation catalyst for diesel engin




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New Technologies in Engine Design and Pollution Abatement Devices                                                               3
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Commercially available GDI technology* represents a major
breakthrough for greatly reducing fuel consumption in automobiles


    The fuel is directly injected into the cylinder, this allows for quicker and more
     precise control of air to fuel ratios
    In GDI engines pumping losses are reduced under light loads, boosting fuel
     economy
    Since the fuel supply is more precisely controlled combustion can occur at much
     higher air to fuel ratios (> 40:1)
    Since GDI engines are less susceptible to knocking, they run at higher
     compression ratios, this provides more torque at low- to mid - rpm ranges, this
     also aids fuel economy




*Not considered in the technology package for determining cost effective strategies for reducing emissions from road
vehicles for the year 2010. Final Report: A Cost Effective Study of the Various Measures likely to Reduce Pollutant
Emissions from Road Transport for the Year 2010, Touch Ross & Co., November 1995, European Commission.

                                                                                                                                    16
New Technologies in Engine Design and Pollution Abatement Devices                                     3
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However, new catalytic converter technology is needed since GDI engines
produces significantly higher NOx emissions than conventional automobiles


   Current catalytic converter technology requires an
    exact air to fuel stoichiometry in order to guarantee
    a 99% percent reduction in HC, CO and NOx
    emissions. GDI and Diesel engines run at much           Catalytic Converter Chemistry
    higher air to fuel ratios
                                                                    (illustrative)
   Any increase in the air to fuel stoichiometry, as in
    diesel or GDI engine technology, inhibits the
    catalytic converter from reducing NOx since the
    higher oxygen levels will decrease CO levels

   While the combustion process at high air to fuel
    ratios produces significantly less NOx, it is the
    ineffectiveness of the 3-way catalytic converter to
    remove NOx which results in higher emissions



                                                                                                          17
New Technologies in Engine Design and Pollution Abatement Devices                                       3
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The major challenge for automotive and catalyst manufacturers is to
reduce NOx under conditions of excess oxygen

    Lean NOx or (DeNOx) catalysts are being
     developed which create a fuel rich micro-
     climate where hydrocarbons in the exhausts
     reduce NOx to nitrogen
                                                       Studies have shown that high
    A DeNOx catalyst will require changes in the      sulphur fuel content will greatly
     structural properties of the catalyst surface     reduce the effectiveness of the
                                                       catalyst
    Three basic systems are being developed
                                                       DeNOx systems currently under
            Passive - where no reductant is           development require fuels with
             added                                     sulphur content less than 50 ppm
            Active - where 2 - 3% additional fuel
             is added upstream of the catalyst
            Adsorption - NOx is selectively
             adsorbed and stored until the catalyst
             is ready to convert it

                                                                                                            18
New Technologies in Engine Design and Pollution Abatement Devices                                      3
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Mitsubishi and Toyota have successfully introduced GDI automobiles
in Japan because sulphur content in petrol is approximately 30 ppm



    30 - 35% better fuel consumption
    95 - 97% reduction of NOx emissions
    NOx reduction is accomplished through a
     high Exhaust Gas Recirculation (EGR)                     A“Gentleman’s agreement”
     techniques and newly developed                           has resulted in market
     DeNOx catalysts                                          levels of sulphur in petrol of
    The EGR and DeNOx catalyst requires                      approximately 30 ppm
     low sulphur fuels
            EGR - to prevent sulphur
             corrosion in the engine
            DeNOx catalyst -
             sulphur forms an impenetrable
             barrier on the active surface area


                                                                                                           19
                                                                                                      3
New Technologies in Engine Design and Pollution Abatement Devices
                                                                         Swed Gov’t cost ben 970203


Toyota’s GDI engine employs a NOx storage reduction catalytic converter
combined with EGR technology




    At high air to fuel ratios NO is           NOx storage         NOx reduction
     converted to NO2 by platinum                    NOx engine
     catalysts and temporarily stored                emissions
    When the engine runs at
     stoichiometry the NO2 is released to
     mix with HC and CO to be                                                           exhaust from
     catalytically converted to N2                                                    catalytic converter

    At 1,200 rpm with 40% EGR,
     a 95% decrease in NOx emissions
     is obtained
                                                  Lean burn          Stoichiometric
                                                    range                range


                                                                                                            20
New Technologies in Engine Design and Pollution Abatement Devices                                        3
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California has recently introduced a new reformulated gasoline with a 30
ppm sulphur content to ensure the proper functioning of LEV technology



                                                                    California has been the
    The extremely low sulphur level is to ensure
                                                                    most pro-active state in
     that LEV and ULEV pollution abatement
                                                                    the US in reducing
     devices work correctly
                                                                    emissions from road
    According to Ford higher sulphur levels in                     transport
     fuels disrupts the proper functioning of
     onboard diagnostic equipment
    Ford reports that sulphur effects are larger for
     LEV and ULEV vehicles than with traditional
     pollution abatement equipment




                                                                                                             21
New Technologies in Engine Design and Pollution Abatement Devices                                          3
                                                                              Swed Gov’t cost ben 970203


Oxidation catalysts alone or combined with particulate filters can be retro-
fitted on to diesel vehicles but require sulphur diesel content under 75 ppm


    Over 1,000 buses and trucks have been fitted in Scandinavia with oxidation catalysts,
     filters or CRT (Continuous Regenerating Trap) packages
    Both technique reduces CO and HC emissions, CRT also greatly reduces particulate
     emissions
    While the catalyst does not remove particles it removes the organic material which
     contributes to particle mass
    Ceramic wall flow filters have been developed which can remove up to 90% of the
     particulates contained in diesel exhausts
    Filter regeneration techniques include
         fuel additives
         catalytic coatings to initiate particulate combustion
         combining filters with oxidising catalyst upstream (CRT) - NO2 levels are
          increased in the exhaust which in turn “burns-off” the particles on the filters

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New Technologies in Engine Design and Pollution Abatement Devices                                        3
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There are over 1800 CRT units in operation in Europe




     Reductions of CO, HC and PM by            Sulphur content in diesel must be
      over 90% is achieved                       lower than 75 ppm
     Long-term engine tests in                 No HDV manufacturer sanctions
      Scandinavia have shown that                the retro-fitting of CRT technology
      there are no apparent negative             on existing vehicles or offers it as
      effects on engine wear                     extra equipment on new units
     No external muffler is needed




                                                                                                             23
  External Environmental Cost Benefits                                                                                        4
                                                                                                 Swed Gov’t cost ben 970203


   The external costs of air pollution has been estimated in other EU projects*


       The purpose of the ExternE project was to develop a unified methodology for
        quantifying the environmental impact and social costs associated with the production
        and combustion of energy
       External costs are defined as costs associated with an activity of a group on a second
        group which are not fully accounted for by the first group (e.g.):
       health effect costs for senior citizens from truck transport in cities
                       –   corrosion effects on buildings from power generation
                       –   crop damage from road transport
       In the cost benefit study, Coopers & Lybrand summarised the data from the ExternE
        project into units of economic value damage (ECU per tonne pollutant; net present
        costs) for airborne NOx and PM from transport for each country in EU-12


* European Commission, DGXII - ExternE, 1995.
*European Commission, DGXI - Cost Benefit Analysis of the Different Municipal Solid Waste Management Systems:
    Objectives and Instruments for the Year 2000, Final Report, Coopers & Lybrand, March 1996
                                                                                                                                  24
External Environmental Cost Benefits                                                                            4
                                                                                   Swed Gov’t cost ben 970203


There are large uncertainties in determining the true costs of air
pollution




                              Dispersion                       Impact on
 Emissions                  (concentration)                    receptors                    Costs

 • uncertainties in      • uncertainties in appointing   • uncertainties in the    • uncertainties
 calculating emissions   the source of pollutants        dose response functions   associated with the
 from road transport                                                               actual costs
                         - inherent uncertainties        •receptors (e.g.):
                                                                                   associated with the
                         associated with air pollution   - population
                                                                                   response
                         dispersion models               - crops
                                                                                   - health care costs
                                                         - buildings
                                                         - forests and rivers      • uncertainties in the
                                                                                   current value of
                                                                                   receptors
                                                                                   -the value of human
                                                                                   life
                                                                                   -costs associated
                                                                                   with “nonproductive”
                                                                                   individuals
                                                                                                                    25
External Environmental Cost Benefits                                                       4
                                                              Swed Gov’t cost ben 970203


There are three important valuation techniques for estimating the costs of
pollution from road transport




                                                                                               26
External Environmental Cost Benefits                                                       4
                                                              Swed Gov’t cost ben 970203


Effects on human health represent the largest proportion of unit
damage costs estimates




                                                                                               27
External Environmental Cost Benefits                                                     4
                                                            Swed Gov’t cost ben 970203


Unit economic values for damage in Europe per pollutant emitted in each
country (ECU per tonne emitted) was estimated as follows




                                                                                             28
External Environmental Cost Benefits                                                                               4
                                                                                      Swed Gov’t cost ben 970203


The estimated benefit in terms of externalised costs of a reduction in
sulphur fuel content is between 400 - 700 million ECUs per year*




 *Calculated for the current vehicle park. If sulphur levels are reduced, new emission reduction
 technologies can be introduced and subsequent costs benefits will be different.
                                                                                                                       29
Sulphur in Fuels - Benefits of Sulphur Reduction
                                                                       Swed Gov’t cost ben 970203


Table of contents

  1      Summary


  2      Sulphur’s Effect on Emissions


  3      New Technologies in Engine Design and Pollution Abatement Devices


  4      External Environmental Cost Benefits




                                                                                                    30
Sulphur in Fuels - Benefits of Sulphur Reduction
                                                                       Swed Gov’t cost ben 970203


Table of contents

  1      Summary


  2      Sulphur’s Effect on Emissions


  3      New Technologies in Engine Design and Pollution Abatement Devices


  4      External Environmental Cost Benefits




                                                                                                    31
Sulphur in Fuels - Benefits of Sulphur Reduction
                                                                       Swed Gov’t cost ben 970203


Table of contents

  1      Summary


  2      Sulphur’s Effect on Emissions


  3      New Technologies in Engine Design and Pollution Abatement Devices


  4      External Environmental Cost Benefits




                                                                                                    32
Sulphur in Fuels - Benefits of Sulphur Reduction
                                                                       Swed Gov’t cost ben 970203


Table of contents

  1      Summary


  2      Sulphur’s Effect on Emissions


  3      New Technologies in Engine Design and Pollution Abatement Devices


  4      External Environmental Cost Benefits




                                                                                                    33
                                              Swed Gov’t cost ben 970203




Sulphur in Fuels -    Final Report          Arthur D. Little AB
                      February 12, 1997     Box 70434
Benefits of Sulphur                         107 25 Stockholm
Reduction                                   Telephone +46 8 698 30 00
                      Swedish and Finnish   Telefax +46 8 698 30 02
                      Governments
                                                                           34

								
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