Development of a pilot plant for flue gas cleaning

Luleå University of Technology, Lapland University of Applied Sciences and University of Oulu has strengthened the competence in flue gas purification in the Interreg Nord project NYEP (New technology for energy efficient particle separation from flue gases).

Tayebeh Darbandi and Mikael Risberg, Luleå University of Technology

Despite the fact that modern heating equipment provides very good combustion with small emissions of environmentally hazardous substances in gaseous form, the emissions of particles are too high. On the scale in question (boilers up to approx. 500 kW) are the best separation methods far too expensive. An absorber does not provide equally good purification but in return provides the opportunity for recovery of heat energy from the flue gases. World Health Organization (WHO) reported that particles up to 2.5 μm in size were the fifth largest cause in 2015 premature mortality in the world and proposed stricter emission requirements in the future. Therefore, is of importance to further develop cheaper gas cleaning equipment for small scale boilers. The next step is to do further optimization of the technology and find out if the efficiency could be improved further. When this is done it would be of interest to incorporate companies that want to further develop the technology to be a commercial product for the market.  

In the project a pilot plant for flue gas cleaning was constructed and measurement of the particle cleaning efficiency was performed. The reduction for the particle size smaller than 3 µm was around 40%, and for particle size larger than 3 µm was around 70%. The cleaning technology has also been shown to work on flue gases from burning of different fuels like pellets created from mining waste. In the project also the long-time stability of the absorption solution was tested and after 800 no deterioration for the absorption solution was found.  

Pilot plant for flue gas cleaning

The added value of the cross-border cooperation was the knowledge transfer. LTU’s knowledge of CFD technology in connection with the absorption technology utilized has been disseminated to Finland, which increased their know-how. Knowledge how to process and burn various fuels like mine waste and municipality waste have been disseminated from Finland by Lapin AMK and University of Oulu to LTU in Sweden together with information how to perform sustainability and techno-economic assessment. LTU has also increased the knowledge how to create models of the generator from the work performed to University of Oulu about multi-phase modelling of the generator that will be used in the future for designing of this part of flue gas cleaning equipment.  

Read more CFD modeling of the forces in the wet scrubber acting on particulate matter released from biomass combustion – ScienceDirect