Bio-oils from arid land plants: Flash pyrolysis of Euphorbia characias bagasse

The devolatilization of the bagasse obtained by solvent extraction of dried Euphorbia characias, a bushy plant growing in arid land of the Mediterranean area, was investigated under rapid heating conditions at atmospheric pressure using a bench-scale fluidized bed pyrolyser. Particle heating rates exceeded 10⁴°C s^?1. Bagasse was fed continuously at the rate of 6 g h^?1 directly into a sand bed fluidized by nitrogen operating in the temperature range of 400°–750°C. The yields of oils, gases and chars are reported. A maximum oil yield of 44% (wt/wt) (moisture free bagasse) was obtained at 500°C. Yields of gases, CO, CO₂, C₁–C₄ hydrocarbons increased with the rise in temperature, reaching a maximum at 750°C. Elemental analyses showed that the composition of oils and chars was dependent on pyrolysis temperature. The nitrogen content is fairly high; an upgrading process could be necessary for its remotion before the use of the bio-oil as combustible. The other characteristics of oils fall in the range of oils derived from other biomass feedstocks. Chars have a high HHV (15.36 MJ kg^?1 at 500°C), representing a valuable fuel.