On the other hand, the water content ranges between 20 and 25 wt.%, and decreases slightly with operating temperature, resulting in an increase of the calorific value of the bio-oil, although the differences in the range studied are low. Thus, the higher heating value of the bio-oil produced in this study is in the 16–18 MJ kg− 1 range. Regarding viscosity, the addition of the heavy organic compounds collected in the demister and filters results in a more viscous bio-oil compared to the fraction retained in the scrubber. However, the viscosity of the whole bio-oil is still low, between 24 and 41 cP at 40°C, and increases slightly with pyrolysis temperature due to the lower water content of the bio-oil obtained at high temperatures.