Life Cycle Management of Municipal Solid Waste Perspectives and by li3490

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									   Life Cycle Management of Municipal
               Solid Waste:
                   Perspectives and Tradeoffs

                                            Keith Weitz
                                            May 29, 2008



                           RTI International is a trade name of Research Triangle Institute



3040 Cornwallis Road   ■   P.O. Box 12194 ■ Research Triangle Park, North Carolina, USA 27709
Phone 919-541-6973                    Fax 919-541-7155                      e-mail kaw@rti.org   1
                    RTI International

RTI is an independent, non-profit research organization formed in
1958 and dedicated to improving the human condition. RTI’s main
areas of research include:

  Health Sciences
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  Education and Training
  Social and Economic
  Development
  Advanced Technology


                                                                    2
      NPR’s All Things Considered:
             May 4, 2007
If I'm concerned about global warming what should I do with my
banana peel?
Possible options:
   Landfill
   Compost
       backyard
       dedicated facility
   “Waste-to-energy”

What if I’m concerned about cost, energy conservation, and/or
sustainability?

                                                                 3
Quick Points on Municipal Solid Waste

There is a lot generated and
disposed even after
aggressive recycling.                                300                                   5

It’s a mix of different                              250




                                                                                               Pounds/Person/Day
                                                                                           4




                               Million Metric Tons
materials, not homogeneous.                          200
                                                                                           3
                                                                                                                   Total
                                                     150
It has energy value (perhaps                         100
                                                                                           2                       Per Capita

3,000 to 5,000 btu/lb on                                                                   1
                                                     50
average).
                                                      0                                    0

It is a local burden and/or                                1960 1970 1980 1990 2000 2005

resource.                                                       U.S. Waste Generation

It stinks…
                                                                                                                           4
      California Organics Waste Stream
               Characterization

                                                 Other
About 40 million tons of                        Organics
organics are disposed                 Branches
statewide.                      Leaves/Grass                              Inorganics


Organics breakdown:
                                    Food
   70% carbon-based organics
   30% is readily compostable
   21% is paper                                                           Lumber
                                      Plastic
   15% is food
                                                           Paper
Regional characterization of
organics being developed.                  Readily Compostable Organics
                                           Other Carbon-based Organics

                                                                                       5
             Presentation Outline

Introduction of the application of the life cycle concept
to waste management.
Review of waste management options:
   Energy producers:
      Landfill
      Waste-to-energy
   Energy savers:
      Recycling
      Composting

Summary of life cycle tradeoffs.
                                                            6
             Life Cycle Assessment

A systems analysis, not
isolated operations.
Considers upstream and
downstream burdens.
Multi-media and multi-
pollutant.
Main components:
   Inventory Analysis
   Impact Assessment
   Interpretation
                                     7
                  Life Cycle of Solid Waste

                                Collection




                                                                   Ash
                                                      Waste-to-
  Composting         Landfill          Recycling                  Landfill
                                                       Energy




Compost Product                     Remanufacturing
   End Use                             Facility




                                                                             8
 Life Cycle Process Boundaries


              Energy      Materials




Solid                                      Products
              Waste Management
Waste          Activity/Operation          Energy


                     Water
          Air       Pollution   Residual
        Emissions                Waste



                                                      9
Life Cycle GHG Emission Boundaries
     for Solid Waste Management




                                     10
                            Landfill

Designed and operated
according to Federal
regulations.
Conventional, bioreactor, and
ash landfill design types.
Different gas management
options:
   Venting
   Collection and flaring
   Collection and utilization for
   energy recovery
                                       11
 US Federal MSW Landfill Standards

Location restrictions.
Composite liners requirements.
Leachate collection and removal system requirements.
Operating practices.
Groundwater monitoring requirements—requires testing.
Closure and postclosure care requirements.
Corrective action provisions for control and clean up of landfill
releases to meet groundwater protection standards.
Financial assurance for environmental protection during closure
and post-closure care.
                                                                    12
    Landfill Leachate Collection and
      Treatment: Offsite or Onsite


                                                   t
                                                 en
                                             atm
                                          Tre
                                     te
                               fsi
                             Of




                             On
                               sit
                                   e      Tre
                                             atm
Leachate Collection System                       en
                                                   t




                                                       13
    Landfill Gas Collection and
Management: Flare or Energy Recovery


                                       re
                                    Fla




                                 En
                                   erg
                                       y   Re
                                                co
                                                  ver
                                                      y

Landfill Gas Collection System


                                                          14
        Landfill Burdens and Benefits

  Life Cycle Burdens                   Life Cycle Benefits
Energy and emissions                 Energy recovery and offset of
associated with material inputs      utility sector emissions
(e.g., liner)
                                     Revenue from sale of energy
Energy and emissions
associated with landfill operation   Long term carbon storage

Landfill gas emissions
Energy and emissions
associated with leachate
collection and treatment


                                                                     15
   Landfill Gas Collection Efficiency

Landfill gas contains about                                         70,000
50% methane which is a




                               Annual Carbon E m issions (M TCE )
                                                                    60,000
potent greenhouse gas.
                                                                    50,000


Gas collection and control                                          40,000


can greatly reduce methane                                          30,000


emissions.                                                          20,000


                                                                    10,000
Assumed gas collection
                                                                        0
efficiency can significantly                                                 Landfill (vent)   Landfill (flare)   Landfill (energy)

impact carbon emissions.



                                                                                                                                      16
      “Waste-to-Energy” Systems

Thermal Systems:
  Mass Burn
  Gasification
  Pyrolysis
  Plasma Arc

Non-Thermal Systems:
  Anaerobic digestion
  Hydrolysis (fermentation)


                                  17
           Mass Burn Technology

Well proven technology for MSW.
Minimum waste preparation required.
Designed to meet Federal, State and
Local environmental regulations.
Higher capital cost.
Reduces waste volume by 90%.
Metals can be recovered for recycling.
Ash can be reused or landfilled.

                                         18
Mass Burn WTE Plant: Water and Air
     Pollution Control Systems


                                     ter
                                   wa
                                ste
                              Wa




                                Ba
                                  gh
                                    ou
 Modern Mass Burn WTE Plant           se




                                           19
 New Emerging Waste Management
         Technologies

Many new and emerging waste
technologies are being
developed and marketed to
communities.
Cost and environmental
performance of new and
emerging waste treatment
technologies is uncertain.
Better understanding of all
issues associated with
adopting new waste treatment
technologies is needed.
                               Schematic of Waste Gasification


                                                                 20
Waste-to-Energy Burdens and Benefits

  Life Cycle Burdens                   Life Cycle Benefits
Energy and emissions                 Diversion of MSW from landfills
associated with facility operation
                                     Energy production and offset of
Energy and emissions                 utility sector emissions
associated with transport of
recovered metals to                  Metals recovery and recycling
remanufacturing plants
                                     Revenue from sale of energy
Energy and emissions                 and recyclables
associated with transport of ash
to landfill
Energy and emissions
associated with ash disposal

                                                                       21
Net Total Energy Consumption for WTE
          and Landfill Options
                                   1,000,000


                                           0
 Annual Energy Consumption (MBTU




                                                WTE   Landfill (vent)   Landfill (flare)   Landfill (energy)
                                   -1,000,000


                                   -2,000,000


                                   -3,000,000


                                   -4,000,000


                                   -5,000,000


                                   -6,000,000




                                                                                                               22
Net Total Life Cycle Carbon Emissions
    for WTE and Landfill Options

                                  500,000


                                  400,000
 Annual Carbon Emissions (MTCE)




                                  300,000


                                  200,000


                                  100,000


                                        0
                                             Landfill - Vent   Landfill - Flare   Landfill - Energy   WTE
                                  -100,000


                                  -200,000




                                                                                                            23
Components of WTE Carbon Balance

       30,000


       20,000


       10,000


            0
MTCE




                 Net Total   WTE Plant   Electricity Offset   Ash Landfill   Ferrous Offset
       -10,000


       -20,000


       -30,000


       -40,000




                                                                                              24
    WTE Electricity Production and
      Assumed Utility Offset
The mix of fuels used to
produce electricity varies
throughout the U.S.
The fuel(s) displaced by
WTE can significantly impact
results of an environmental
analysis.




                                     25
                     Recycling

Designed to accepted different
types of material:
  Mixed MSW
  Commingled recyclables
  Presorted recyclables

Automated or manual
Market for recycled materials
are regional and fluctuate.

                                 26
     Recycling Burdens and Benefits

  Life Cycle Burdens                  Life Cycle Benefits
Energy and emissions                Diversion of MSW from landfills
associated with separate
collection                          Conservation of energy and
                                    virgin resources
Energy and emissions
associated with MRF operation       Revenue from sale of
Energy and emissions                recyclables
associated with transportation of   Forest carbon storage
materials to remanufacturing
                                    associated with paper recycling




                                                                      27
                       Composting

Designed to accepted
different types of material:
   Organics only
   Mixed MSW
Highly automated in-vessel to
less automated windrow and
aerated static pile designs.
Markets for compost product
are regional and dependant
on product quality.

                                    28
    Composting Burdens and Benefits

  Life Cycle Burdens                    Life Cycle Benefits
Energy and emissions                 Diversion of MSW (organics)
associated with separate             from landfills
collection
                                     Potential for offset of other
Energy and emissions                 products (fertilizer, etc.)
associated with compost
operation                            Revenue from sale of compost
                                     product
Energy and emissions
associated with for transportation   Soil carbon storage
of compost product and residuals


                                                                     29
    Summary of Life Cycle Tradeoffs

Landfills and WTE are well established and tested, accept unprocessed
waste, have pollution control requirements, and can recover significant
amounts of energy from waste.
Recycling and composting typically require separate collection and can
save significant energy by offsetting upstream production activities.
Landfill has generally been the cheapest option while WTE typically the
most expensive option, and recycling and composting typically fall in-
between.
WTE most efficient at producing energy while recycling most efficient at
saving energy.
WTE, recycling, and composting all avoid landfill methane generation.
Materials and energy recovery create significant (upstream) benefits.
                                                                           30
Back to the NPR Question: What should
       I do with my banana peel?
 Backyard composting perhaps the best, but all options are pretty
 good…
 Answers are typically site-specific and depend on values:
    waste management facility design and operation
    cost versus GHG emission reductions
    local versus global impacts
 What about other organic and inorganic materials in the waste?
    glass
    plastics
    metals
    paper
    yard waste
                                                                    31
               Take Home Thoughts

Municipal solid waste can provide feedstock for bioenergy
production…but perhaps challenging to use.
All waste management options cost money, consume energy, and create
environmental burdens.
Waste management options can create significant energy related
benefits:
   Energy savings (recycling, composting)
   Energy production (LFG to energy, WTE)
Where is the tipping point between energy consumption and energy
savings/production?
Energy savings/production from waste can also produce significant
savings of GHG emissions.
Source reduction is perhaps a win-win option.
                                                                      32
                         Thank You



                                                   Keith A. Weitz
                                                  RTI International
                                                3040 Cornwallis Road
                                                   RTP, NC 27709
                                                  Ph: 919-541-6973
                                                 Fax: 919-541-7155
                                                 Email: kaw@rti.org




Visit our web site: https://webdstmsw.rti.org                          33

								
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