Characterization of the liquid products in the pyrolysis of residual chañar and palm fruit biomasses

Abstract

The endocarp in the chañar (Geoffroea decorticans) fruit, the pericarp in the white palm (Copernicia alba Morong) fruit and the exhausted white palm seeds from the extraction of oil are all residual lignocellulosic biomasses from the food processing of these fruits. The pyrolysis was performed at 550 C in a fixed bed reactor during 30 min under N2 flow with a 15 C/min heating ramp from room temperature. In all the cases a liquid product (bio-oil and tar) with yields from 35 to 50 wt.%, a gas product and a solid product (char), were produced. The tar represented from 5 to 20 wt.% of the liquid product. The highest bio-oil yield (47 wt.%) was obtained with the chañar fruit endocarp and the highest tar yield (8.8 wt.%) was obtained with the white palm seeds. The bio-oils contained mainly acids (from 6 to 18 wt.%), aldehydes and ketones (from 2 to 10 wt.%) and phenols (from 4 to 13 wt.%), with a high water content (from 44 to 81 wt.%). Their pH was acidic and the densities ranged from 0.97 to 1.24 kg/dm3. The tars had mainly phenols and oxygenated compounds of high molecular weight. After these results, these residual biomasses can be considered as a potential source for energy or fuels and valuable chemical products.