Title: 04 Source types emissions inventories
1Source 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
2Learning 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
3Different 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
4Typical problems related to sources
- Traffic
- local problems
- hot spots
- Industrial sources
- local, hot spots
- toxic
- specific impact
- Regional and large scale
- background
5Typical problems related to sources
- Home heating, cooking / energy use, regional
dependency - Smoking
- Consumer products
-
6Source 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)
7Point 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
8Line sources
Road transport, Railways, Inland navigation,
Shipping Aviation
The lines are sections of the road,
railway-track, river, canal, sea-lane, aircraft
path
9Area 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)
10Area sources Tokyo
11Area sources
Storage of coal. Eastern Europe
Waste deposit. Lagos, Nigeria
12Area sources Forest fires
Wildfire Heilongjiang, China
Surface fire, tropical deciduous forest, India
13Source manifolds
- Big enterprises
- Waste burning
- Smelters
- Cement
- Brick factories
- Petrochemical
14Source manifolds
Suralaya power plant, Indonesia
Ahmedabat power plant, India
15What 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
16Classification 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 ?
17Compounds (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
18Air pollution management model
19What 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
20Source 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).
21Source 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)
22Source apportionment of coarse (PM10-2.5) and
fine (PM2.5) particulate matter in Metro Manila
(XRF)
23Emission 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
24Emission 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
25Emission 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
26Emission 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
27Area Distributed Data in Fields
- A Field is a set of Data that are distributed in
one of the defined Grids
28Line 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
29The 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).
30Emissions of SO2
Bilbao, Spain
31Emissions of NOx, based on consumption statistics
32(No Transcript)
33Rapid 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
34Raw 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
35Advantages 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
36Disadvantages 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
37Screening 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
38Model 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.)
39Examples 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
40- 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,
41Definition 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
42Examples 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
43Example 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
44Source 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
45Example 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
46Heavy 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