Fate of Minerals in the Fast Pyrolysis Process

The distribution of minerals between the products of biomass fast pyrolysis is important with respect to the sustainability of the chain as well as for downstream applications. In case biomass residues from agricultural origin are for example used for renewable energy production, it is important the nutritional value of the minerals can be recovered and recycled to the original environment. For most pyrolysis oil applications it is disadvantageous if high mineral concentrations are present in the product. This work investigates the influence of the biomass composition and the pyrolysis process conditions on the distribution of minerals between the products using three pyrolysis setups. Two existing plants, at 5 and 200 kg/h are representative of a full scale pyrolysis plant, while a small, 0.5 kg/h setup has been built specifically to recover all product from the process for analysis. Preliminary results with the 5 and 200 kg/h setup show the non-metal elements (S, P) are transferred to a large extent to the liquid product. The concentration of alkali (Na, K) and earth alkali metals (Ca, Mg) is on average 3% of the concentration found in the original biomass.