Industrial and domestic coal combustion:
A South African perspective
Harold Annegarn
School of Geo and Spatial Sciences, North-West
University, Potchefstroom
[email protected]; [email protected]
“Summit on Black Carbon and Other Emissions from
Combined Cooking+Heating and Coal Heating Stoves ”
Ministry of the Environment, Warsaw
29th - 30th May 2017
Air quality issues in RSA
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Domestic combustion emissions (coal, wood, kerosene)
Coal-fired power plant emissions
Wild-fire emissions (local and regional)
Vehicle emissions
Industrial emissions
Wind-blown dust from mine tailings
Examine solutions that are:
“Leapfrogging with strategies that are affordable,
scalable, inclusive and inventive”
A tale of township pollution – biomass and
coal combustion in South African informal
settlements
Credit - Philip Lloyd, UCT
3
“Imbuala” brazier-type coal stove,
used in informal settlements
Ambient or indoor pollution hazard?
Credit: Attie van Niekerk, Nova
Annegarn
4
The mystery of smoke revealed:
Combustion aerosol particle from domestic coal burning –
condensed VOCs (volatile organic carbons)
Annegarn
5
Ambient monthly average PM10 particulate concs: Soweto
Monthly mean PM10 concentrations
conc.
Monthly
mittlere Ko
n ze n tramean
tio n derparticulate
9 S am me lstatio
nen
3)³]
S owe tos
[µ g/m
(µg/m
300
g rob [µg/m³]
fein [µg/m³]
250
200
Old South African
PM10 guideline
150
100
New South African
PM10 guideline
50
0
Ja n
F eb
M rz
A pr
Ma i
Ju n i
Ju li
A u g Se p
Ok t
N ov
De z
Examples of emissions from top-down and
bottom-up coal fire lighting methods
Basa njenga Magogo
“Make fire like the old lady”
7
Classical fire-lighting methodology
TLDD – Top-Lit Down Draft
Pyrolysis front moving downwards through fuel bed
Unburnt fuel
= air pollution
Flame zone
Cool zone –
SVOC condensation
VOCs and SVOCs combusted
Hot zone –
VOC distillation
Hot zone –
VOC distillation
Flame zone
8
Sulphur is liberated throughout
the burn: emitted as SO2 or H2S
Energy Poverty
If residential areas (post-apartheid) are extensively
connected to electrical grid, why is there not a reduction in
use of domestic solid fuel combustion?
Electricity is not an economic option for space heating!
Energy poverty – a definition:
Spending more than 10% of household disposable
income on energy services
 A scalable concept
The poor suffer disproportionate health and safety risk
from use of domestic energy
Baseline: negative externalities of domestic energy use
- defective housing and energy systems
Annegarn
Photos by Susan Cook
11
Rebuilding after a shack fire
Annegarn & Guy
12
Leapfrogging the Rights to Clean Air
– the South African Experience
1. A constitutional Right to Clean Air
2. Public health and power plant emissions – a
novel approach to emission offsets
3. Reducing domestic emissions – improved
stove testing procedures
4. Satellite images for determining regional air
quality and DALYs
A constitutional Right to Clean Air
South African Constitution provides for:
• And whereas everyone has the constitutional right to an
environment that is not harmful to their health or wellbeing;
• And whereas everyone has the constitutional right to
have the environment protected, for the benefit of
present and future generations, through reasonable
legislative and other measures.
The South African approach
• South African environmental law is based on the concept
of cooperative governance, rather than centralised
command and control
• Change from source control to management of
receiving environment
• Individual rights and agency, entrenched public
consultation
• Regulators, industry environmental AQ managers,
AQ consultants become important agents of protecting
environmental rights
Southern African thermal power generation:
location and rated power
Thermal power
generation (MW)
3600
Courtesy of Gavin Fleming CSIR
Acid rain!
Or not?
The passive diffusive sampling network distribution
Power plant
source region
© Annegarn 1 April 2011 NACA
17
Net acidic
deposition
(meq m-2 y-1)
Contours derived
from passive
deposition network
© Annegarn 1 April 2011 NACA
18
Preliminary Results from GOME
Daily NO2 column depth over southern Africa
2000-08-18
2000-08-31
Annual mean SO2 compared to
critical levels
© Annegarn 1 April 2011 NACA
20
Acid deposition verdict?
• Not guilty as charged!
• BUT….
• Stack emissions of SO2 and NOx exceed permissible
emission rates; occasional ambient ground level exceedences
• Department of Environment Affairs has devised
a novel offsets policy:
• In terms of Atmospheric Emission Licences (AEL), company
given conditional exemption to continue current emissions
(for five years) if they implement, monitor and demonstrate
exposure reduction to domestic combustion emissions
within impact zone surrounding power plant (~50 km )
© Annegarn 1 April 2011 NACA
21
Reduction strategies for
power plant offsets
• Insulation of dwellings to reduce space heating needs
• Fuel/stove substitution with improved stoves or different
energy carriers
• Electricity too expensive for space heating & cooking
• LPG gas a technically viable option but
– May need a continuing fuel subsidy
– No indigenous LPG supply; lacking infrastructure for bulk LPG import
• Kerosene fuelled stoves are poorly constructed and a serious
fire accident hazard; odour of kerosene socially undesirable
• Available solid fuel (wood and coal) stoves still high emitters of
PM2.5 - need for improved stove technologies to burn widely
available, inexpensive or no cash cost fuels
Reducing domestic emissions – improved stove
testing protocols
• We recognised a need for standardised method for
performance evaluation of improved cookstoves
• Devised new test from first principles –
SeTAR Centre Heterogeneous Testing Protocol,
– Based on mass balance measurements
– Recognises that the system under test is [stove plus fuel] cannot devise a useful test using a universally standardised
fuel or a standardised burn sequence
Satellite images for determining
regional air quality and DALYs
Regional or continental scale estimates of human
exposure and externality costs make use of aerosol
climatology results
• Can be based on ground level monitoring, emissions
inventories and dispersion modelling
or
• Use of satellite based retrievals of aerosol products.
We have devised a method using 10-day average
aerosol optical depths and unsupervised classification
to derive a aerosol classification over South Africa
(Kneen et al. Atmos Envir. 2016)
Classes defined on the ten-day average time-series patterns
created using ten-year seasonally averaged PM2.5 column depth
Google Earth image with the PM2.5 classification (40x1) version
superimposed.
Higher resolution image of the Johannesburg metropolitan
conglomerate (southern Gauteng Province) draped over a Google
Earth satellite image, with partial transparency of the classes.
Uses and limitations of satellite
aerosol retrievals
• Satellite retrievals provide realistic spatial and seasonal concentrations
over large areas – useful for estimating Disability Adjusted Life Years
(DALYs) on epidemiological scales
• Limitations are satellite retrievals miss nocturnal level high
concentrations in concentrated informal settlements. These account for a
large fraction of population exposure
(Cumulative exposure = concentration x duration x number exposed).
• Regional exposure assessment models, such as the IIASA Greenhouse
Gas - Air Pollution Interactions and Synergies (GAINS) model, need to
incorporate nested regions to address this factor
(http://gains.iiasa.ac.at/models/)
SAWB AEROCOMMANDER 690A ZS JRB,
equipped for tropospheric aerosol and gas measurements
From whence cometh the smoke?
© Annegarn 1 April 2011 NACA
28
Aerosol transport pattern dubbed the River of Smoke
Biomass burning
smoke and haze
exiting off east
coast
4 September 2000
Provided by the SeaWiFS Project,
NASA/Goddard Space Flight Center,
and ORBIMAGE
Satellite: OrbView-2 Sensor: SeaWiFS
Image Date: 09-04-2000
Image captured by CSIR Satellite
Application Centre
RIVER OF
SMOKE
Conclusions
• Regulation, monitoring, mitigation and exposure
assessment from solid fuel combustion are not operated
in isolation
• The strict regulatory approach developed in the USA and
Europe, and aspirational guidelines set by WHO, are
products of a particular historical evolution, and are not
necessarily the best or most cost effective tools for air
quality management in developing countries
• Constant evaluation of received wisdom, and innovative
regulation, monitoring and assessment should be part of
our continuing efforts to realise our
RIGHT TO CLEAN AIR
Energy Institute
Acknowledgements to ERGO GOLD Ltd for
permission to use data and access to sites;
To NRF and Eskom for long-term support for
atmospheric, energy and remote sensing research;
To University of Johannesburg (SeTAR Centre Grant)