Co-pyrolysis of palm kernel shell and discarded medical bottle for biofuel production: Synergistic effect and product distribution

Abstract

The present study uncovered the effect of pyrolysis temperature (400, 500, 600, and 700 °C), and biomass-to-plastic ratio (100:0, 25:75, 50:50, 75:25, 0:100) on the product distribution and synergistic effect during co-pyrolysis of palm kernel shell (PKS) and medical bottle (MB). The highest bio-oil yield of 65.93 wt% was attained at 500 °C and PKS:MB ratio of 25:75. To determine the synergistic effect, the product distributions (yield and chemical composition) were compared with those obtained from pyrolysis of individual components. The positive synergistic effect on the production of hydrocarbons and inhibition of acids were most dominant at PKS:MB ratio of 75:25. The presence of PKS-derived oxygen radicals and hydrogen abstraction from MB can accelerate the formation of hydrocarbons via secondary cracking and deoxygenation reaction. The produced oil at PKS:MB ratio of 50:50 showed better characteristics compared to PKS-derived oil which contains higher carbon (45 % higher), and hydrogen content (66 % higher), and lower oxygen content (71 % lower).