04 Source types emissions inventories

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Source types and emissions inventories
Presentation by Dieter Schwela Stockholm
Environment Institute, University of York
Malé Declaration Workshop on Air Quality and
Health Impacts 19-22 February 2007, Bangkok,
Thailand
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Learning objectives

• Identification of different source types
• Identification of key pollutants
• Simple air quality management model
• Understanding source apportionment
• Understanding emissions inventories
• Applying a rapid assessment procedure

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Different types of sources
Stationary sources Factories, Power
plants Smelters, Production processes Fossil
fuel extraction/distribution Solvent
production/use Waste treatment/disposal
Smaller sources such as dry cleaners and
degreasing operations Mobile sources Cars,
buses, trucks, trains, aircraft Natural
sources Windblown dust Volcanic eruptions
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Typical problems related to sources

• Traffic
• local problems
• hot spots
• Industrial sources
• local, hot spots
• toxic
• specific impact
• Regional and large scale
• background

5
Typical problems related to sources

• Home heating, cooking / energy use, regional
  dependency
• Smoking
• Consumer products

6
Source distinction

• To identify source characteristics outdoor air
  pollution sources are divided into
• Point sources (emissions from stacks, e.g. power
  plants and industries)
• Line sources (emission from traffic along a road
  or a street)
• Area sources (e.g. residential heating and other
  small sources distributed over an area)

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Point sources

• Mainly large emitters that can
• be identified at a specific location
• defined by
• A single, identified stack
• ü  Geographical co-ordinates,
• ü  Combustion and non combustion activities
• ü  and other specific data.

Factory smoke Western Beijing (BBC)
Copper smelter. rural China
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Line sources
Road transport, Railways, Inland navigation,
Shipping Aviation
The lines are sections of the road,
railway-track, river, canal, sea-lane, aircraft
path
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Area sources
Many small sources spread over an area Position
not well defined Normally no or small stacks.

• Typical area sources
• Stationary sources such as residential fuel
  combustion
• Solvent use (e.g., small surface coating
  operations)
• Product storage and transport distribution (e.g.,
  gasoline)
• Light industrial / commercial sources, many small
  enterprises
• Agriculture (e.g., feedlots, crop burning)
• Waste management (e.g., landfills, open air waste
  burning)
• Miscellaneous (e.g., forest fires, wind erosion,
  unpaved roads)

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Area sources Tokyo
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Area sources
Storage of coal. Eastern Europe
Waste deposit. Lagos, Nigeria
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Area sources Forest fires
Wildfire Heilongjiang, China
Surface fire, tropical deciduous forest, India
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Source manifolds

• Big enterprises
• Waste burning
• Smelters
• Cement
• Brick factories
• Petrochemical

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Source manifolds
Suralaya power plant, Indonesia
Ahmedabat power plant, India
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What is emitted
Suspended particulate Gaseous pollutants matter
TSP, PM10, PM2.5, PM1.0 Diesel exhaust Sulphur
dioxide SO2 Coal fly-ash Carbon
monoxide CO Mineral dusts Nitrogen
oxides NOx Metal dusts and fumes Ammonia NH3 Ac
id mists Hydrocarbons HC Fluorides Volatile
organic compounds VOC Paint pigments Polycyclic
Aromatic Hydrocarbons PAH Pesticide mists Halogen
compounds HF HC Carbon black Oil
smoke
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Classification of further outdoor air pollutants
Secondary pollutants Odours Sulphuric acid
mist H2SO4 Hydrogen sulphide H2S Ozone
O3 Carbon disulphide CS2 Formaldehyde
HCHO Mercaptans R-SH R1 S
R2 Peroxyacetyl-nitrate PAN Others ?
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Compounds (indicators) from some selected sources
Source category
SOX
NOX
CO
VOC
TSP/PM10
Power generation
xx
xx
x
x
x
Residential, commercial combustion
x
x
xx
x
xx
Process industry with combustion
xx
xx
x
x
xx
Non- combustion industry
x
x
(xx)
xx
x
Extraction and distribution of fuels
x
x
x
xx

Solvent use


xx

Road transport
x
xx
xx
xx
xx
Other transport
x
(xx)
x
x
x
Waste disposal and treatment
x
x
xx
xx
xx
Agricultural activities


x
x
Natural sources


x
x
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Air pollution management model
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What is source apportionment?

• When air quality standards are exceeded
• Need to understand the contribution of individual
  sources
• Support for modellers to develop control options
• Support for policy makers to adopt control
  options
• Development of clean air implementation plans
• Cost-efficiency analysis of control options

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Source apportionment Some methods

• Spatial and temporal analysis ( are high
  concentrations observed on a regional scale or
  only at a few hot spots?).
• Assessing the age of an air mass accompanied with
  trajectory analysis.
• The use of satellite information to corroborate
  transport (e.g., Saharan dust storm exposure on
  U.S. sites).
• Model the dependence of PM on ozone to determine
  a component of PM that is photo-chemically
  produced.
• The use of tracers-of-opportunity and species
  ratios accompanied with trajectory analysis
  (e.g., using potassium to identify smoke exposure
  from forest fires).
• Use of multi-element nuclear techniques (e.g. ion
  beam analysis, x-ray fluorescence, neutron
  activation analysis).

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Source apportionment of particulate matter

• Primary PM
• Combustion-generated
• Mechanically generated
• Windblown dust
• Resuspended dust
• Seasalt
• C(PMP) Function (emission rate, dispersion
  variables, removal rate)
• Secondary PM
• Sulphites
• Ammonium nitrate
• Organic aerosols
• C(PMS) Function (precursor concentrations,
  other species concentrations, reaction
  constants, atmospheric conditions,
  cloud/fog droplet interactions, removal
  rate)

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Source apportionment of coarse (PM10-2.5) and
fine (PM2.5) particulate matter in Metro Manila
(XRF)
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Emission inventories

• Complete All sources included point, area,
  line
• Consistent Same definitions applied by all
  countries
• Appropriate and up-to-date emissions factors
• Transparent Contains all information necessary
  to check how emission estimates are obtained
• May be costly

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Emission inventories
Geographical Information System (GIS)
Calculation of Emission Fields
Modelling
Population
Industry
Traffic
Consumption

• stacks
• process
• consumption
• production
• time variation

• road information
• road type/class
• vehicle class
• emission factors
• time variation

• distribution in sub areas

• fuel type
• emission factors
• temp. variation
• time variation

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Emission factors (f)

• From literature
• boiler
• type of oil
• refining
• raw material characteristics
• operating conditions
• E.g. SOX
• sulphur content in fuel
• sulphur retained in ashes
• control efficiency
• type of process

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Emission estimate
E P f
E emission rate (g/h) P production, fuel use
etc... (ton/h) f emission factor (g/ton)
point area line
sources
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Area Distributed Data in Fields

• A Field is a set of Data that are distributed in
  one of the defined Grids

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Line Distributed Data Road Traffic

• Road Nodes Sub - Nodes
• Road Link Geographical Definition
• Road Link Physical Properties
• Road Link Classification
• Traffic Volume and Distribution
• Traffic Flow Properties

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The emission for a given road is a function of

• Speed,
• Road gradient,
• Year of calculation (technology level of the
  vehicle),
• Number of cars in each vehicle class
• CO and NOx from traffic are calculated by
  multiplying
• Traffic intensity
• Cars/hour x Length of the road km x Emission
  factor g/(kmcar).

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Emissions of SO2
Bilbao, Spain
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Emissions of NOx, based on consumption statistics

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(No Transcript)
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Rapid assessment procedure

• Effective way of assessing air releases by each
  source, or groups of similar sources, within the
  study area
• Convenient assessment of the effectiveness of
  alternative pollution control options
• Based on documented, extensive past experience of
  the nature and quantity of pollutants generated
  from each kind of source, with or without
  associated control system
• Prediction of anticipated releases from a given
  source

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Raw waste load factors
Source type
Generated loads
Activity type, magnitude and other
source- specific inputs
Control systems effectiveness factors
Released loads
Control type
Bold Field survey data Bold italic Model output
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Advantages of Rapid Assessment approach

• Convenience of use
• Integrated source inventories of air pollutant
  sources in highly complex situations
• Times spent a few weeks
• Resources necessary modest
• End result more reliable than that from direct
  source monitoring
• Estimation of effectiveness of alternative
  control schemes
• Formulation of rational control schemes

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Disadvantages of Rapid Assessment approach

• Statistical validity of inventory predictions
• Predictions only indicative as there is
  significant variation in normalized emissions
  between similar sources
• Control measures need be considered preliminary

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Screening and classification of pollution
generating activities (UN classification)

• Activities not adequately defined
• Agriculture, Hunting, Forestry Fishing
• Mining and Quarrying
• Manufacturing
• Electricity, Gas and Water
• Construction
• Wholesale and Retail Trade
• Transport, Storage and Communication
• Community, Social and Personal Services

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Model for compiling air emission inventories
Emission Ej of a pollutant j Ej function
(source type, unit of activity, source size,
process or design particularities, source age
and technological sophistication, source
maintenance and operating practices, type and
quality of raw materials used, type, design and
age of the control systems employed, ambient
conditions, etc.)
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Examples for the variable in the argument of Ej

• Source type
• cement manufacturing
• vehicle traffic
• external fuel combustion
• Unit of activity
• raw materials consumed
• products manufactured
• mileage of vehicles
• aircraft landing and take-off cycles in an
  airport
• Source size
• related to process selection
• related to vehicle size categories
• Process or design particularities
• different kinds of kilns in the production of
  lime and cement
• different types of furnaces in metallurgical
  industry

s
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• Source age and technological sophistication
• failure of older systems
• elusion of technical innovation
• legislation and enforcement aspects
• Source maintenance and operating practices
• related to product quality
• for smaller sources improper maintenance is the
  rule
• Type and quality of raw materials used
• dictate the process to be used, offer some of the
  most important air pollution management options
• Type, design and age of the control systems
  employed
• removal efficiencies, downgrading of performance
  with time
• Ambient conditions
• wind velocity/ rainfall TSP emissions of roads
  and material storage facilities
• temperature road traffic emissions,

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Definition of emission factor for pollutant j
ej Ej kg/yr / Source activity units of
activity/yr
ej function (source type, process or design
particularities, source age and technological
sophistication, source maintenance and operating
practices, type and quality of raw materials
used, type, design and age of the control
systems employed, ambient conditions, etc.) ej
is the key objective of the air emissions model
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Examples of units of emission factors
ej Ej kg/yr / Source activity units of
activity/yr Mass-based emission factors Ej kg
of particle mass released/year Source activity
kg of mass of fuel burned/year ej kg of
particle mass released/kg of mass of fuel
burned/year Task-based emission factors Ej kg
of gas mass released/year Source activity km
traveled/year ej kg of gas mass released/ km
traveled
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Example 1 Manufacture of paper and paper
products

• Plant survey
• Paper production is 70 000 t/year
• Sulphate pulp mill
• Digester is uncontrolled
• Recovery boiler is with direct contact evaporator
  and Venturi scrubber
• Smelt dissolving tank is uncontrolled
• Lime kiln is uncontrolled
• Diffuse sources exist

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Source Unit Source Emissions factors Emissions factors Emissions factors Emissions factors Releases Releases
U size TSP SO2 CO H2S Hg TSP SO2 CO H2S Hg
1000U/y kg/U kg/U kg/U kg/U kg/U t/y t/y t/y t/y t/y
Sulphate pulping
Digester
Uncontrolled tn 70 0.6 1.2 40.6 80.5
Recovery boiler DCE Recovery boiler DCE
Venturi scrubber tn 70 24 3.5 5.5 6 1.5 1680 245 385 420 105
Smelt dissolving tank Smelt dissolving tank
Uncontrolled tn 70 3.5 0.1 5.5 0.1 0.2 245 7 385 7 10.5
Lime kiln
Uncontrolled tn 70 28 0.2 0.05 0.3 0.1 1960 10.5 3.5 17.5 7
Miscellaneous sources tn 70 0.3 17.5
Subtotal (present sheet) Subtotal (present sheet) 3885 263 774 445 123
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Example 2 Exhaust emissions from heavy duty
diesel powered trucks and buses

• Description of car fleet
• Number of trucks 3.5-16 tons 1 000
• Number of trucks gt 16 tons 200
• Number of buses gt 16 tons 300
• Annual mileage trucks 52000 km
• Annual mileage buses 20000 km
• Average speed 25 km/h
• Average trip length 8 km
• Cold/hot starts 75/25
• Mean ambient temperature 200C
• S-content in diesel 0.5

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Heavy duty diesel trucks Source size Emission factors Releases
1000U/y TSP SO2 Nox TSP SO2 Nox
kg/U kg/U kg/U t/y t/y t/y
S-content in diesel 0.5 0.5
Annual mileage trucks 52000 km 52000
Annual mileage buses 20000 km 20000

Number of trucks 3.5-16 tons 1000 1000 km 52 0.9 4.29 11.8 46800 111540 613600

Number of trucks gt 16 tons 200 52 1.6 7.26 18.2 16640 37752 189280

Number of buses gt 16 tons 300 20 1.4 6.6 16.5 8400 19800 99000

Subtotal (present sheet) 71840 169092 901880