Chemical Engineering and Processing, Vol.124, 235-244, 2018
Fodder radish seed cake pyrolysis for bio-oil production in a rotary kiln reactor
Fodder radish seed cake (FRSC) was pyrolyzed in a rotary kiln reactor at different rotation speeds (0, 3 and 6 rpm) and inert gas flow rates (0.25, 0.75 and 1.25 L/min). Pyrolysis of the bran (oil-free FRSC) were also carried out to investigate the effect of residual oil present in the FRSC. The experiments showed that the optimal rotation speed for bio-oil production is 3 rpm, with a bio-oil yield of 60.99 wt.%. The experiments carried out at different inert gas flow rates showed an increase of bio-oil yield at 1.25 L/min (63.22 wt.%). The residual oil in the FRSC increased bio-oil yield, since FRSC bran (oil-free) pyrolysis presented a bio-oil yield of 49.34 wt.%. The bio-oils obtained from FRSC pyrolysis, as well as its bran, presented distinct chemical composition. FRSC bio-oil presented, besides aromatics, amines, amides, and nitriles (nitrogen containing functional groups). The bio-oil obtained from FRSC bran pyrolysis presented higher aromatics content than the bio-oil from FRSC, with lesser amines content and absence of nitriles. The bio-oil obtained from FRSC pyrolysis at 3 rpm was the one that presented the more adequate physicochemical properties for use in industry and for energy production. Due to the composition, the bio-oils can be used as fuel, to obtain chemicals and as a feedstock for gasification.