EFFECT OF TEMPERATURE AND PARTICLE SIZE ON PYROLYSIS YIELD FROM PAPER MULBERRY (Broussonetia papyrifera)

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.