Abstract:
Pyrolysis technology is most commonly employed to convert widely
available biomass into useful biofuel products to meet energy needs and obtain
chemical feedstocks. In the present study, pyrolysis of paper mulberry
(Broussonetia papyrifera) was carried out with the aim to study the product
distribution and their chemical compositions. The optimum process conditions for
maximizing the pyrolytic yield were also determined. Experiments were performed
in a well-swept resistively heated fixed-bed reactor to examine the effect of
temperature and particle size on pyrolysis yields. Different ranges of temperature
350 °C, 450 °C, 550 °C and particle sizes 1 mm, 2 mm and 3 mm were used and
their effect was evaluated on pyrolysis of Broussonetia papyrifera. The pyrolysis
products were collected within three different groups as non-condensable gases
products, condensable liquids and solid biochar. The result showed that the highest
biochar product was attained at 350 oC and 3 mm particle size while the highest
bio-oil yield was obtained at 450 oC and 2 mm particle size. On the other hand, the
optimum temperature and particle size for gas yield was 550 oC and 1 mm. The
bio-char with highest fixed carbon content (61%) and calorific value (26.5 MJ/Kg)
was observed at 550 °C and 3mm. Nutrient elements like Mg, Al, Cu, Zn, Ca and
K were found in high concentrations. The GC-Ms analysis of bio-oil showed that it
was rich in alkanes, alcohols, ketones and cycloalkanes. The bio-oil was acidic (pH
ranging 3.4-3.9) at all temperatures and particle sizes. The heating value of bio-oil
was maximum at 3 mm and 550 °C (25 MJ/Kg). The gas product was mainly
composed of CO2, CO, CH4 and hydrocarbons. The results of the present study
showed that the pyrolysis of Broussonetia papyrifera produce carbon rich, high
energy and relatively pollution-free potential solid biofuels and bio-oil.
