Pelletizing of fuel blends mixed with lignin for energetic use in small scale combustion units

Abstract

As part of future bio-economy concepts technical lignin, by-products derived from the pulp- and paper industry, may be recycled for further utilization. Via a specially developed process the liquid lignin lye can be converted into a solid state. The lignin granules were mixed with a blend of canola straw and peeled oat bran in different proportions (1–2 wt.-%) to adjust the characteristics of the mixtures for pelletizing. Combustion tests with the produced pellets were carried out in a small scale combustion unit (25 kW) showing that depending on the amount and kind of lignin CO-, SO2- and particulate matter emissions are affected. Through further optimization of fuel mixtures and by means of secondary measures existing emission limits could be complied.