Leena Fagernäs

Characterization of biomass-based flash pyrolysis oils

Abstract An analytical scheme for the characterization of biomass-based flash pyrolysis oils was developed. The scheme was based on fractionation of the oils with water and on further extraction of the water-soluble fraction with diethylether. The chemical composition of the fractions was analyzed by gas chromatography–mass spectrometry. The physical and chemical nature of straw, pine and hardwood pyrolysis oils was determined and compared with each other. Correlations between the physical properties and chemical composition of the oils were drawn. The characterization method will be utilized in further work for stabilization and upgrading tests of flash pyrolysis oils.

Behaviour of Organic Compounds in Biomass Drying

In the thermal drying of wet biomass with steam or flue gases prior to conversion or combustion, organic compounds are released and constitute a load on the environment as emissions to the air or as effluents to natural waters. They can also cause operational problems by contributing to the formation of deposits in downstream sections. The release of these organic detrimental substances was studied both under atmospheric and pressurized conditions. Laboratory-scale fluidized-bed drying experiments were carried out at the temperature range of 150 – 350 °C for pine and birch barks and peat. The hydrophilic and lipophilic compounds released were analyzed by different chromatographic methods. In addition, dust, deposit and condensate samples from industrial bark and peat dryers were analyzed.