Air ir pollu llution from soli lid fuel l combustion - im implic lications for Atmospheric chemis istry ry Stuart Piketh North-West University MOSS Summer School 28 Nov-3Dec 2016
• World faces significant challenges in terms of impacts of air pollution on human health – this is particularly true of emissions from solid fuel ~3 billion people combustion • Particulate Matter (PM) is accepted as posing the GLOBALLY rely on solid highest health risk to exposed populations (Silva et fuel combustion as a primary energy source = al., 2013) increased exposure to • South Africa in turn has similar challenges and has elevated PM concentrations daily the added problem that many industrial sources are currently unable to meet the Minimum emission standards – enter Emissions Offsets
Mortality lin linked to outdoor air pollution in in 2010 annually Lelieveld et al., 2015 2010 - 2050
Why all the fuss about air pollution?
Hersey et al., 2015
Different cartographic views of the world Poverty
• S.A. is an important role player in emissions from coal fired power stations (13 coal fired power stations – typically 3600 MW delivering 95 % of energy requirement (some nuclear, renewabe and hydro) • Regionally • Internationally • RSA emissions of total PM, NO 2 and SO 2 are higher than 15 European countries included in the study for comparison purposes (Von Blottnitz, 2006) • SA is the 7th biggest emitter of carbon emissions from coal- fired plants globally (International Energy Agency, 2012 after International Energy Agency, 2010). (26 th biggest economy)
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• SA is is a majo jor role le pla layer r in in coal l fir fired power r statio ion emiss issio ions on a glo lobal l and regio ional l sc scale le • Largest power generator in Africa (based on 2011 data): Sudan and South Sudan Tunisia Algeria Egypt South Africa Libya Morocco Nigeria Ethiopia Kenya Mozambique Source: U.S. Energy Information Administration, 2014. International Energy Statistics. http://www.eia.gov/cfapps/ipdbproject/IEDIndex3.cfm?tid=2&pid=2&aid=7, accessed 22/04/2014. U.S. Department of Energy, Washington DC.
Impacts of Combustion on Air Quality
Emissions are a f function of f input fu fuel and combustion conditions
A comparison of average ash contents (%), calorific values (MJ/kg) and sulphur contents (%) of fuel coals from the major coal consumers in the world, namely China, US, India, Russia, Germany and South Africa (in descending order of coal consumption (Mtpa)).
Minimum Emissions Standards - Comparison
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25 25 Back to basics 20 20 Mass Fraction (%) Mass Fraction (%) Igbafe, 2007 15 15 10 10 5 5 0 0 Jan Jan Feb Feb Mar Mar Apr Apr May May Jun Jun Jul Jul Aug Aug Sep Sep Oct Oct Nov Nov Dec Dec Monthly mass fraction distributions of particulate sulphate relative to total sulphur at Elandsfontein between September 2004 and August 2005 10 10 Spring Spring Summer Summer Autumn Autumn Winter Winter 9 9 8 8 7 7 ug m -3 ug m -3 6 6 5 5 4 4 3 3 2 2 0 0 2 2 4 4 6 6 8 8 10 10 12 12 14 14 16 16 18 18 20 20 22 22 24 24 Time of day /h Time of day /h Diurnal variations of mean particulate sulphate concentrations at Monitoring Station Elandsfontein for the various seasons observed over southern Africa
Regio ional l sc scale le ass ssessment of f deposit itio ion usin sing an in inferentia ial l model l for r both th wet t and dry ry deposit itio ion Total Dep 4.45 kg.ha -1 .yr -1 Josipovic et al, 2009
Carbon monoxide also emitted
Background: Mercury Sources Anthropogenic Hg Natural Hg contribution contribution (Mg.year-1) (Mg.year-1) Fossil fuel combustion 810 Oceans 2682 Biomass burning 675 Artisanal gold mining 400 Non-ferrous metal production 310 Desert 546 Vegetation 448 Cement Production 236 Waste Incineration 187 Forest 342 Caustic Soda production 163 Hg evasion 200 Mercury Production 50 Agriculture 128 Pig iron & Steel production 43 Lakes 96 Coal bed fires 32 Geothermal Activity and Volcanoes 90 Vinyl Chloride Monomer production 24 (Lindqvist & Rodhe, 1985; Ebinghaus et al. 1999; Pacyna et al. 2006; Pironne et al. 2010)
Methodology Dabrowski et al. 2008; Leaner et al. 2009; Masekoameng et al. 2010 : ME = C (mass) x C (Hg) x 10 -6 (1-ERF) where: C (mass) = Amount of coal burned per annum (tonne y -1 ) C (Hg) = Hg concentration in combusted coal (mg.kg -1 ) ERF = Emission Reduction Factor (Depends on control device) Fabric Filters (FFs) : 0.5 Electrostatic Precipitators (ESPs) : 0.1 Recommended emission reduction factors (UNEP, 2005 & 2011) Too conservative and not representative of the removal capability (Roos, 2011)
Methodology This Study utilised the bottom-up approach (Zysk et al, 2011): ME=FC*C*(1- ƞ) where: ME= Mercury emission (kg) FC= Fuel consumption (M.tonne y -1 ) C= Concentration Hg in fuel (mg tonne -1 ) Ƞ= Hg removal efficiency (%) Bituminous coal-fired plants + emission control device = Higher removal efficiencies (ICR, 1999) EPA (2010): FFs : 0.89 ESPs : 0.36
Methodology
Results - Currently fitted vs idealised FFs replacement of ESPs 2,5 2 Hg emission (Mg y-1) 1,5 1 0,5 0 Power Station Current
Size in um
Kwadela Township - Pil ilot project for Offset in interv rventions
Experimental design Indoor & Person sonal al Temperatu erature Monitoring Monitoring iButtons ns (Kitchen, Living room, Bedroom, (10mm Dorr-Oliver Cyclone) External, Stove) 1.7 L.min -1( ±5%) 1.6 m AMBIEN IENT Mobile Monitoring STRU TRUCT CTUR URED ED INTERV TERVIEW IEWER ER- Station QUEST UESTION IONNAIR NAIRES ES Meteorological parameters (21% Settlement) MetOne BAM 1020 (PM 10 ) MetOne E-BAM (PM 2.5 ) 4 Sampling Campaigns Winter 2013 Jul. – Sept. Summer 2014 Feb. - May Winter 2014 Jul. – Sept. Summer 2015 Feb. – Apr.
Ambient concentrations of f PM on cold days – Kwadela
In Indoor concentrations of f PM
Addressing the spatia ial ext xtent of the problem of healt lth im impacts associated wit ith domestic burnin ing
So Source Apportionment – Kwadela
Oth ther sources of f PM do need consideration Unpaved roads Vehicles Burning of Waste Veld fires
Particulate matter concentrations in in Kwazamakuhle and Hendrina
Summary of emissions for Power stations, industry and domestic burning Source SO2 (tpa) PM10 (tpa) Power stations 1,433,524 52,407 (53.22) (81.5%) Other source (industry, BB, 319,735 43,873 (18.2) (44.6) Vehicles,Dust Domestic burning 3,958 2,186 (0.2) (2.2) Total 1,757,217 98,466 Parenthese gives % of Total Scorgie and Thomas, 2006
Impacts on non-accidental mortality current emissions (%) Source Pollutants Non-accidental Respiratory Mortality Hospital Admissions Power Stations 3 0.6 Industrial 34 35 Vehicles 9 11 Domestic burning 50 50 SO2 28 5 NOx 3 4 PM10 69 90 Scorgie and Thomas, 2006
68 8, 9 June 2015
Ground Data
Monthly Trends
Monthly Trends Township sites are 51 and 78% higher on average than urban/suburban and industrial sites, respectively
Diurnal Trends
Diurnal Trends Summer Fall Winter Spring Maxima at township sites are a factor of 2-3x higher than for urban/suburban residential and industrial sites
Air quality in South Africa
Im Impacts of f reducing Ambient concentrations Lindeque et al, 2015
Thank you
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