CondensabLe AeRosol from non Ideal Stove Emissions (CLARISE)

Lead Research Organisation: University of Manchester
Department Name: Earth Atmospheric and Env Sciences

Abstract

Domestic wood burning is now the dominant direct source of airborne particulate matter less than 2.5 microns (PM2.5) in the UK (~38 % of the total in 2019 according to the National Atmospheric Emissions Inventory) and can account for a high fraction of the carcinogenic potential of particles even in urban areas. Current emission inventories underestimate the impact of residential wood burning, as they focus on optimum use conditions and exclude condensable material, which can contribute to both primary emissions and secondary aerosol production. Based on evidence from recent studies of wood combustion, we propose that 'non-ideal' operational conditions, including ignition, reloading, maloperation and use of unconventional fuels are a large and unaccounted for source of particulate pollution in the UK. The CLARISE project brings together unique expertise in biomass burning experiments, emissions monitoring, atmospheric complexity analysis and regional modelling. We will study emissions from domestic heating stoves, under a range of non-ideal conditions, providing high time resolution measurements of transient event emissions during operation.

CLARISE will study wood burning in a dedicated stove test facility at the University of Manchester and will use a combination of state of the art online instruments that can capture the transient emissions with a high time resolution. An oxidation flow reactor (OFR) will be used to simulate the effect of atmospheric chemical ageing on the emissions and allow insight into the formation of secondary, or 'condensable' particulate. Gas and particulate samples will also be collected for subsequent analysis in the laboratory at the University of York. A novel suite of mass spectrometric methods will be used to generate volatility profiles of the emissions under both ideal and non-ideal conditions, using the popular Volatility Basis Set (VBS) approach. Where molecules are identified in the secondary particulate, these will be compared against the Master Chemical Mechanism (MCM), the gold standard explicit atmospheric organic chemistry model, in order to identify gaps in mechanistic understanding that should be targeted for future studies on reaction kinetics.

The experimental data and parameterised outputs will then be used in regional atmospheric model simulations to predict the relative amounts of secondary particulate that can be expected from both the ideal and the non-ideal emissions relative to the ideal primary particulate that is already accounted for in the national inventory. This will allow us to assess not only the relative importance of non-ideal emissions but also their estimated contribution to PM2.5 in the UK and beyond. We will also produce a schedule of emission modes, fuels and emitted VOCs that will be of interest to the scientific community, stove manufacturers/installers, the third sector and policymakers, as many of the problem non-ideal areas can potentially be addressed by user education, engineering controls in the stoves and policy interventions.

Publications

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