Environment: Heating, innovative system for measuring fine particles

ENEA and Innovhub Experimental Stations for Industry have created an innovative system for measuring fine particles emitted by biomass stoves, fireplaces and boilers, designed to become a European standard.

This activity is part of the EU project "IMPRESS II - Metrology for Air Pollutant Emissions", which has the task of developing methods of analysis and measurement of some atmospheric pollutants, including nitrogen oxides and PM 2.5 and PM10 particulates, with the purpose of improving the technology behind the heating systems fueled by wood and pellets.

"Modern domestic appliances are much more efficient in terms of performance and environmental impact than in the past, but biomass combustion remains an important source of particulate matter to the detriment of air quality.

This is why the European Union is moving in the direction of imposing increasingly stringent emission targets; only in Italy more than 90% of the PM10 generated by the domestic heating sector derives from small wood-burning appliances.

So far, different methods have been used to measure particulate emissions and, at times, with mixed results, causing confusion on the market. To this aim we are working, together with other 17 European partners, on a standard measurement method, applicable to all types of biomass stoves and boilers.

This system will have to yield repeatable results with traceable and guaranteed accuracy and provide consumers with reliable information on the emissivity characteristics of a particular appliance or boiler, " Francesca Hugony of the ENEA Energy Efficiency Unit Department explained.

For the tests, ENEA and Innovhub chose a pellet stove with a nominal power of 8 kW, with stable emissions (necessary to make a comparison between the different samples) to verify the reliability of the new device.

The system consists of a "dilution chamber" where the combustion gas is mixed with dry, filtered and preheated air at a constant temperature of 35-40 ° C. The sampling is managed remotely, through a control software that guarantees, unlike other measurement systems, the replicability of the operating parameters.

The sampling system was then sent to three other European laboratories specialized in this field: the coordinator of the INERIS (Institut national de l'environnement industriel et des risques), DTI (Danish Technological Institute) and RISE (Research Institutes of Sweden). For this second phase, tests were also conducted on small-sized  wood stoves.

“Our next step will be to make our sampling tool more manageable in order to put it on the market; that’s why we will propose this technology in the next ENEA "Proof of Concept" call and later on as a method to be included in technical standards.

If it became a European standard, its potential buyers would mostly be certified laboratories. However, it could be useful to universities and research centers conducting experimental tests on combustion systems even as a dilution system.

France, for example, is already interested in our particulate sampling system for some production sectors and in Italy, the Municipality of Milan has asked our partner Innovhub to use the sampling system on a pizza oven in order to verify the emissions of condensable particulate matter[1].

Air pollution is responsible for approximately 400 thousand premature deaths, with annual health costs ranging between 330 and 950 billion euro in Europe. Over 60% of the EU urban population is exposed to particulate levels above the World Health Organization (WHO) guidelines and biomass boilers and other domestic heating systems are "the main responsible."

In order to protect the quality of life of citizens, the limits on air pollutants are becoming increasingly stringent and will also be introduced for those just regulated, such as ammonia and hydrogen fluoride, for which there are no standardized measurement methods at the EU level yet.

The results will enable regulators, plant operators, manufacturers and measurement service providers to comply with emission limits and monitoring requirements, supporting the efforts to ensure cleaner air across Europe for the benefit of public health and the environment.

For more information: http://empir.npl.co.uk/impress/

Francesca Hugony, ENEA – Energy Efficiency Department – Northern Area Regions Laboratory, francesca.hugony@enea.it

[1] Technical note: In the literature there are several definition of condensable particulate matter.