The FunktioMat, SIMO and ILMARI laboratories of the Fine Particle and Aerosol Technology Laboratory in Kuopio had an open house early this May. The three laboratories make it possible to produce functional materials for industrial needs, and fine particle emissions can also be studied in a variety of different ways.
The new FunktioMat laboratory has just been equipped with a flame spray pyrolysis device that makes it possible to produce large quantities of nano-sized metal oxides for industrial needs, for example. Earlier, it took researchers up to one year to produce just one kilo of these metal oxides, but now the process is very quick.
'Our flame spray pyrolysis device enables the production of one kilogram of metal oxides per hour, and our spray pyrolysis device can produce around 700 grams per hour,' says Anna Lähde, who recently secured Academy Research Fellow funding from the Academy of Finland.
Anna Lähde presenting the flame spray pyrolysis device.
The particles produced are nano-sized, and one gram of them can cover the area of a football field. This means plenty of active area in, for example, water purification or energy storage.
In flame spray pyrolysis, the source material is fed to a very high temperature flame in which the nanomaterials are formed in a matter of milliseconds. The precursors are dissolved in an organic solvent. The organic compounds burn in the flame into carbon dioxide and water. The metals in the source material, on the other hand, oxidise and form nanoparticles that move upwards with the carrier gas and end up in a large filter, from which they can be collected for delivery to the clients.
'The source material can be anything that ignites and burns in a flame, for example an organometal. Water can't be used as a source material in this method, but we can produce particles from watery solutions by spray pyrolysis alone. For the time being, the filters are emptied by hand, but this part of the process will also be automated in the future,' Lähde explains.
The FunktioMat laboratory is also equipped with an induction oven that can be used to produce carbon nanostructures, such as graphene, for industrial needs. It takes approximately one hour to produce a couple of grams of graphene in the oven.
The laboratory's induction oven works similarly to household induction ovens; however, the temperatures are higher, reaching 2,600 degrees Celsius at one point of the process. Graphene can be manufactured by removing silicon from the source material, and it can be utilised in energy collection, conducting inks, fine films and wastewater purification.
'We have the advantage of having Savonia University of Applied Sciences' Water Laboratory right next to our facilities, making it possible to easily test our samples,' Lähde says.
Emissions from wood stoves and sauna stoves are studied in the movable SIMO container
The SIMO container - a household combustion simulator - standing on the university yard represents a new approach to the study of fine particles. The SIMO container makes it possible to simulate a house with a wood stove. The other similar container, on the other hand, is equipped with a sauna, making it possible to study various wood-heated sauna stoves. Both the containers are movable. They can be used in various fairs, for example, or be rented out to clients for their own measurement purposes.
'These containers make it possible to study new zero energy homes and also older houses through ventilation adjustments, for example,' Postdoctoral Researcher Heikki Lamberg says.
'In practice, clients can bring in any stove they wish to study, for example a small soapstone masonry heater - the floor of our container is strong enough. We then connect the combustion appliance to the container chimney and to our measurement devices. Here we can study combustion emissions and air quality - for example how to enhance combustion by using a steering system.'
The SIMO container is soon ready for testing. Heikki Lamberg in the photo.
The sampling systems are located in the chimney. During the measurements, the sample is diluted to lower the concentration and the temperature.
Savonia University of Applied Sciences was in charge of building the container's measurement system, which makes it possible to obtain real-time measurement data.
'The container has its own aggregate and pressurised air system, which means that it can be moved anywhere,' Lamberg says.
'In the future, we seek to improve ventilation technology and building services engineering in order to better optimise air supply for wood stoves. This would make it possible to reduce emissions. In addition to boilers, we could also make the function of wood stoves and sauna stoves more automatic.'
Fine particles can be removed from combustion gases
The ILMARI laboratory is also located right next to the containers. For nearly 20 years already, extensive research into the health and climatic effects of combustion emissions has been carried out in ILMARI.
Currently, the laboratory is carrying out the Pyreus project which is investigating various cleaning solutions for combustion gases.
'We study the usage of pyrolysis oil and its combustion emissions, and we are now running a pilot flue gas scrubber system for cost-efficient cleaning of combustion gases,' Research Manager Olli Sippula explains.
This combustion gas scrubber has been designed in ILMARI. Olli Sippula in the photo.
'This solution has been developed especially for small boiler systems that don't have effective combustion gas cleaning systems. Nowadays lots of wet biomasses are used as fuel in small- and medium-sized boilers, and a lot of energy is consumed for water evaporation. In the piloted flue gas scrubber, water gets condensed and this makes it possible to effectively remove fine particles while also increasing the efficiency of heat production.'
According to Sippula, the EU will introduce increasingly tighter regulations on particle emissions of small boiler units, and this is why affordable and cost-effective solutions are now needed.
In households, however, it is more difficult to control combustion gases and emissions.
'People use a wide selection of wood fuels in household combustion. The fuel moisture content can be too high, operational practices vary and the combustion techniques are not easy to control,' Senior Researcher Jarkko Tissari explains.
Emissions from household combustion are also studied in ILMARI. Jarkko Tissari in the photo.
Text: Marianne Mustonen
Photos: Tuija Hyttinen