The Fine Particles Laboratory is focused on the identification and analysis of fine particles emitted by combustion processes, manufacturing processes and road transport emissions. The combination of several measurement methods covers the complete spectrum of emitted particles in terms of size and concentration. The measurements are either performed on-line or the particles are captured on filters for subsequent gravimetric or chemical analysis. The laboratory’s primary focus is on research into the formation and growth of the smallest particles during combustion processes.

The particles are most often extracted directly from the flue-gas stack. However, the concentration is too high for many devices, necessitating the dilution of the flue gas. Two diluters, employing disparate dilution principles, are available for this purpose. Both can be heated to prevent condensation of volatiles and water vapour.

The Palas instrument is employed for the measurement of coarse and fine particle concentrations, facilitating online measurement with one-second resolution, including particle size distribution. This instrument is more appropriate for monitoring lower concentrations, such as those in indoor air quality. Given that the instrument employs the principle of light scattering on dust particles, it is not applicable to the smallest particles due to the laws of physics. The fine and ultrafine fractions of dust particles are quantified through the use of analysers from TSI. In these, particles are initially sorted according to their electrical mobility, and then subjected to condensation of butanol vapour, which serves to enhance their visibility. Consequently, the smallest particles that can be detected are 2 nm in size, which corresponds to a cluster of a few molecules. The physical capture of size-sorted particles is conducted using a cascade impactor from Dekati. The evaluation is performed gravimetrically, with the option of subsequent chemical analysis. In addition to the aforementioned instruments, we also employ the conventional isokinetic sampling of particulate matter on filters for gravimetric analysis, in accordance with the procedures outlined in EN 13284-1.

Furthermore, combustion tests are conducted on an array of fuels within a laboratory setting. In this instance, the combustion apparatus is substituted with a thermogravimetric analyser, wherein a minute sample (weighing just a few milligrams) is combusted under meticulously monitored conditions. Subsequently, all flue gases are fed into the instrument for particle concentration analysis. The advantage of this configuration is the high degree of repeatability and controllability of the measurements. A mass spectrometer can be utilised to analyse the gaseous products produced. Additionally, an aerosol generator is available, which produces a harmless polydisperse aerosol of high concentration, and a particle size analyser for particles dispersed in the liquid medium.

The laboratory’s activities encompass the measurement of filtration efficiency and the evaluation of regeneration potential for a range of filtration materials.

The services we provide include:

• Laboratory thermogravimetric analysis of fuels and materials, including identification of the concentration and size distribution of emerging fine particles in the size range of 2–1000 nm.
• Identification of fine particles in the flue gas of residential solid fuel burning appliences, in the range of 2–1000 nm.
• Identification of fine particles in liquid media, in the range of 0.08–2000 µm.
• Identification of particles in the ambient environment (external and internal), in the range of 2–1000 nm or 1–105 µm.

Equipment

The following apparatus is employed for the purposes of measurement and research:

• Particle counter Palas Promo 2000
• Particle counter TSI OPS 3330
• Electrostatic Classifier TSI 3082
• Condensation particle counters TSI 3775 and TSI 3752
• Cascade Impactor Dekati HT-DLPI+
• Thermogravimetric analyser NETZSCH 449 F3 Jupiter
• Quadrupole mass spectrometer NETZSCH QMS 403 Aëolos Quadro
• Particle size analyzer FRITSCH ANALYSETTE 22 MicroTec plus
• Aerosol generator TSI 3079
• Rotating Disk Thermodiluter TSI 379020A
• Ejector diluter Dekati DI-1000

More detailed information about these devices can be found in the list of equipment.

Selected implemented projects:

• TAČR, no. TJ01000331 "Reduction of the fine particles concentration with using active temperature stabilisation in the flue gases of small sources" (2018-2019).

Selected publications and results:

• POLÁČIK, J.; POSPÍŠIL, J.; ŠNAJDÁREK, L. Size Distribution of Particulate Matter Emitted During Controlled Temperature Rise of Redwood Sample. TOP 2017 Proceedings of abstract. Bratislava: Slovenská technická univerzita v Bratislave, 2017. p. 60-60. ISBN: 978-80-227-4731-8.
• POLÁČIK, J.; POSPÍŠIL, J.; ŠNAJDÁREK, L.; SITEK, T. Influence of temperature on the production and size distribution of fine particles released from beech wood samples. In XXI. International Scientific Conference - The Application of Experimental and Numerical Methods in Fluid Mechanics and Energy 2018 (AEaNMiFMaE-2018). MATEC Web of Conferences. 168. 2018. p. 1-9. ISSN: 2261-236X.
• ŠPILÁČEK, M.; POLÁČIK, J.; POSPÍŠIL, J.; ŠNAJDÁREK, L.; SITEK, T. Fine Particles Emission from Controlled Combustion of Beech Wood in Laboratory Conditions. CHEMICAL ENGINEERING TRANSACTIONS, 2018, vol. 70, no. 1, p. 1945-1950. ISSN: 2283-9216, DOI:10.3303/CET1870325.
• POLÁČIK, J.; ŠNAJDÁREK, L.; ŠPILÁČEK, M.; POSPÍŠIL, J.; SITEK, T. Particulate Matter Produced by Micro-Scale Biomass Combustion in an Oxygen-Lean Atmosphere. ENERGIES, 2018, vol. 11, no. 12, p. 1-10. ISSN: 1996-1073, DOI:10.3390/EN11123359 [IF 2,676].
• SCHÜLLEROVÁ, B.; POLÁČIK, J.; ADAMEC, V.; HRABOVÁ, K.; POSPÍŠIL, J. Influence of temperature parameters on the production of fine particle distribution during the biomass combustion. In 18th International Multidisciplinary Scientific Geoconference SGEM 2018. Conference Proceeding. Volume 18. International multidisciplinary geoconference SGEM. 2018. p. 307-314. ISBN: 978-619-7408-70-6. ISSN: 1314-2704.
• SITEK, T.; POSPÍŠIL, J.; POLÁČIK, J.; ŠPILÁČEK, M.; VARBANOV, P. Fine combustion particles released during combustion of unit mass of beechwood. RENEWABLE ENERGY, 2019, roč. 140, č. 1, s. 390-396. ISSN: 0960-1481.

Selected Master’s and Bachelor’s theses

In the implementation of research and development activities, we try to cooperate with Bachelor’s and Master’s degree students, where the result of cooperation are quality diploma theses. When working on their theses, students have the opportunity to use the facilities and equipment of the laboratory, to participate in the implementation of research projects and to gain a range of practical knowledge:

• KOŠŤÁL, J. Vliv provozních parametrů kotle na přítomnost jemných částic ve spalinách. Brno: Vysoké učení technické v Brně, Fakulta strojního inženýrství, 2017. 93 s. Vedoucí diplomové práce doc. Ing. Jiří Pospíšil, Ph.D..
• HÁJEK, O. Jemné částice emitované při laboratorním spalování biomasy. Brno: Vysoké učení technické v Brně, Fakulta strojního inženýrství, 2018. 55 s. Vedoucí bakalářské práce doc. Ing. Jiří Pospíšil, Ph.D..
• SITEK, T. Ultrajemné částice generované spalovacím procesem. Brno: Vysoké učení technické v Brně, Fakulta strojního inženýrství, 2018. 89 s. Vedoucí diplomové práce doc. Ing. Jiří Pospíšil, Ph.D.

Contact

prof. Ing. Jiří Pospíšil, Ph.D.
Energy Institute, FME BUT
e-mail: pospisil.j@fme.vutbr.cz
tel.: +420 541 142 581