Residential combustion: integration of air Residential combustion: integration of air pollution and climate change issuespollution and climate change issues

M. Viana, F. de Leeuw, C. Guerreiro, M. Vogt, A. Colette,S. Collet, A. Alastuey, X. Querol, A. Lükewille

mar.viana@idaea.csic.es

Ljubliana, October 6th 2015

OutlineOutline

•Background•Objectives•Impacts on emissions•Impacts on air quality•Uncertainties•Mitigation strategies•Summary & Conclusions

BackgroundBackground

- Renewable- EU goal: >20% net energy

consumption in 2020= renewable- Climate-oriented policies

The commercial and residential combustion sector was identified in the majority of European cities as the second-largest contributor to exceedances of PM10 and NO2 LVs (EEA, 2014)

Whereas the use of coal for residential purposes is decreasing in general over Europe, there is currently a growing interest in the use of wood/biomass in residential energy production

BackgroundBackground

• Biomass = renewable source, with evident climatic benefits, and when combusted efficiently, it may be a (nearly) CO2-neutral

• However, its use as residential fuel under non-optimal operating conditions entails negative consequences: low combustion efficiency, poor fuel quality and/or poor maintenance.

• The recent economic recession in Europe and recent changes in consumer habits have encouraged the use of biomass as a residential fuel

Downside: air quality & health

ObjectivesObjectives

To provide an overview of the contribution of domestic combustion to ambient air pollution and climate change across EU:

– quantifying emission trends– quantifying source contributions– assessing the technological/regulatory framework in place– taking into account uncertainties– baseline year: 2012

Total GHG emissions from the Total GHG emissions from the residential sector in 2012residential sector in 2012

Overall, residential sector <20% total GHG emissions

Strong link with population:Germany, UK, Turkey and France

Emission trendsEmission trends

• Emissions not constant across years, depending on meteorological but also economic and social factors

• The relative contribution of emissions from the residential sector (1.A.4.B) over total emissions (sectors 1-7, excl. 5. LULUCF)

Statistically significant (+ & -): 22/33 countries assessed

Residential/total emissions: •Increases: 0.67 to 2.65%/year•Decreases: -0.20 to -3.82%/year

Res. consumption per fuel typeRes. consumption per fuel type

IPCC (2006): solid fuels (coal, coal briquettes), gaseous fuels (natural gas), biomass (wood/wood waste, charcoal, other primary solid biomass), liquid fuels (gasoline or diesel oil)

Gaseous fuels: 34%Biomass: 33%

Fuel type trendsFuel type trends

Germany, Austria, UK, Turkey

Changes over time due to economic & social aspects, also national or EU policies (e.g., banning or incentivising

specific fuel types)

Greece, Ireland, Spain, Czech Rep.

Denmark, Belgium, The Netherlands

Fuel type trendsFuel type trends

Norway, Denmark, Austria, Bulgaria Spain, Greece, Hungary, Croatia, France

Incentives to specific fuel types?Economic recession?

Summary:•Solid & liquid fuels (coal, gasoline/diesel) generally decreased across Europe between 1990 and 2012•Gas & biomass mostly increased•Change in trend ( to ) around 2005 for biomass: economic, regulatory & social factors•Large uncertainty in the biomass emissions inventories:unreported collection & others may account for as much as 50%

Fuel trends Fuel trends vsvs. BaP emissions. BaP emissions

Relationship between biomass/coal consumption as residential fuel and BaP emissions from this sector

A correlation between BaP emissions and biomass consumption trends is detectable, even though a direct relationship cannot be extracted with the data available

Impact on air qualityImpact on air quality

Annual mean BaP concentration (2012) (AirBase & EMEP)

• The uncertainty in the BaP map may be considered large

• Monitoring data missing in large parts of Europe: when concs.<0.4 ng/m3 no regular monitoring data required; modelling or indicative measurements optional

>25% of EU27 population in zones where LV was exceeded in 2012

Impact on air qualityImpact on air quality

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BaP

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Monthly variations of BaP (ng/m3), averaged for all operational stations for which monthly data is available in AirBase (2012)

•Analysis of PM2.5 & BaP levels in ambient air (EEA, 2014) indicated that only for a small number of stations a clear trend can be observed•The set of stations that could be used for an analysis during the heating season was even smaller, and only 3 (out of 56) stations showed a significant trend (for PM2.5)•In sum: it is not possible to define areas where air pollution is mainly attributable to residential combustion (based on Airbase data alone)

Monthly BaP concentrations

Impact on air qualityImpact on air quality

Impact on air qualityImpact on air quality

Impact on air qualityImpact on air quality

Why such high impacts?Why such high impacts?

• Biomass is a renewable fuel with clear climatic benefits

• However, impact on local and regional-scale air quality (PM10, PM2.5, BC, EC & OC):– open fires for agricultural/garden waste (banned in most areas)– use of non-regulated stoves– use of non-standardised fuels (like treated, painted or not

sufficiently dried wood)– inadequate use of stoves (under sub-optimal conditions)– inadequate maintenance of stoves in homes

• Technical measures, regulations & guidance, and economic instruments in place in different countries

UncertaintiesUncertaintiesSeveral sources:(a)Emissions inventories(b)Emission factors, dependant on technology, type of fuel, fuel quality (including humidity content), and operating mode(c)Estimation of fuel consumption, by type of fuel and quality for the different technologies of ovens and boilers.(d)Field vs. laboratory conditions

(a) BaP emissions:•LRTAP Convention: parties are invited to report emissions data for PAHs and BaP•Within the EU28, only 20 countries reported BaP officially (2012): major gap in inventories•EMEP estimates BaP emissions for their modelling domain, based on officially reported emissions and applying gap-filling strategies•As a result: officially reported BaP emission of the 20 countries (2012) was 180 tonnes (EEA, 2014), vs. 241 tonnes estimated by EMEP (EMEP/CEIP, 2014)•Discrepancies also regarding trends

UncertaintiesUncertainties

• Particle emission factors determination requires common methods and practices at the European level. These conditions are not yet met. They should involve lifespan analysis (20-40 yrs.), old technology as well as state-of-the-art, replacement rates, etc.

• 4 different particle sampling procedures can be used (Nussbaumer et al. 2008): SP (solid particles); SPC (solid particles and condensable organic fraction); DT (dilution tunnel); SPFID (solid particles and flame ionization detector)

• Large differences (up to factor of 10!)• Methods SPC or DT are recommended, as they take into account the

condensable organic fraction• Method SPC allows comparability with SP, largely used up to now

(b) Emission factors

(c) Estimation of fuel consumption, by type of fuel and quality for the different technologies of ovens and boilers

(d) Field vs. laboratory conditions

Technical measuresTechnical measures

• Primary measures: technological activities for reducing original emissions from incomplete combustion, such as TSP, PM, CO, NMVOC, PAH, PCDD/F as well as heavy metals and SO2, and NOx. Examples: improving fuel quality, homogenization and stabilization of the moisture contents, improved construction of the combustion appliances, etc. Increasing of appliance efficiency (for all fuels) leads to decreasing emissions (Kubica et al., 2007)

• Secondary measures: applied to remove emissions. Examples: settling chambers, cyclone separators, electrostatic precipitators

Fuel dependant!

Regulations and guidanceRegulations and guidance

• EU-level: Ecodesign and Ecolabelling Directives

• National level: examples, Norway, Germany, UK, France

• Voluntary eco-labelling systems that evaluate the impact of a product on the environment throughout its life cycle:

• information on how various fuel types (types, materials, quality, moisture content) affect output and emissions

• fuel types suitable for the stove• recommendations for the handling and storage of fuels• how the stove is lit• instructions for filling and the volume and size of fuel• instructions for cleaning, inspection and maintenance of the stove

Economic instrumentsEconomic instruments

• Incentives to promote replacement of old stoves: Oslo, Bergen, Madrid,...• Example of Madrid (Spain): www.cambiatucaldera.com

• Installation of new appliances, which should be registered in the database of efficient boilers

• Minimum reduction of 20% in consumption with regard to the period before the installation

• Installation by an official operator/company, which should be registered in the official database

• The stove/boiler removed must be disposed of and inutilised

ENVIRONMENTAL IMPACTS

PLAN RENOVE

Energy savings

(MWh/year)

Emissions reduction:

CO2 (T/year)

Emissions reduction:

NOx (T/year)

Individual boilers 80.000 16.282 52.0

Boiler rooms 23.600 4.814 15.3

TOTAL 103.600 21.096 67.3

Summary & ConclusionsSummary & Conclusions

A) Need to establish (and inforce) policy, control and monitoring systems, and economic instruments at regional, national and EU level.

B) Small combustion installations: large uncertainties, (primary PM2.5, BaP, BC). Linked to emission inventories, emission factors and usage data, and lack of monitoring data.

C) Based on Airbase data alone, it is not possible to define areas where air pollution is mainly attributable to residential combustion.

D) Contributions from residential sector emissions to ambient air quality: <5% - 40% of PM10 and PM2.5 during the heating season.

E) Main reasons: use of non-regulated stoves, inadequate maintenance, use of non-standardised fuels.

F) Modern stoves with high efficiency and low emissions are becoming more and more available on the market.

Thank you for your attentionmar.viana@idaea.csic.es