Pyrolysis of pine wood in a small integrated pilot plant rotating cone reactor

A small integrated pilot plant rotating cone unit has been tested for flash pyrolysis of biomass. The reactor vessel contains a rotating cone, a combustion bed for burning of the produced char, and a riser set-up for solids circulation. Compared to other flash pyrolysis reactors, there is little need for transport gas. The heat carrier material is transported mechanically by the rotating cone, while the produced vapours leave the reactor by displacement through pressure build-up. Preliminary results are presented for tests with pine wood derived saw dust as a feedstock material (up to 10 kg/hr). Oil yields between 50 and 65 wt.% (on wood basis as received) have been achieved at temperatures of 480 to 510 degreesC. Results of oil analysis have been compared with data From literature; densities, pH-values, viscosities and the elemental analysis of the fresh oil are in good agreement with values reported for e.g, the Union Fenosa oil. The produced gas (up to 15 wt.%) contains mainly CO, CO2 and CH4 (in a ratio of approximately 1: 1: 0.1), but hardly any H-2. Char yields in the order of 10 wt.% (on wood basis) have been estimated, a value which is comparable to the figure reported by Wagenaar et al. (1994) for a similar but batch-wise operated, prototype cone reactor. The mass balance closure was about 65-84 wt.%. In-situ burning of the char, one of the special features of this concept, occurred without major difficulties.