Co-pyrolysis of empty fruit bunch and waste tire: A kinetics and synergism analysis

Abstract

The efforts in discovering new, green and sustainable energy sources have been overwhelming, all with the common aim of combating global warming and environmental pollution while protecting the supply security of conventional energy sources. Pyrolysis is a secure thermo-chemical conversion method suitable for the conversion of biomass waste into a product of higher energy value, aimed for energy production. Co-pyrolysis on a blend of feedstock from different sources has captured the attention of the scientific community as it has been demonstrated to be able to overcome undesirable characteristics of the derived products like high acidity and high ash content. The present study demonstrates the co-pyrolysis of empty fruit bunch (EFB) and waste tire (WT) at a mass ratio of 1:1 using a thermogravimetric analyser. The results were compared with the baseline of pure feedstock pyrolysis. It was reported that EFB is more reactive at a lower temperature region (200-325°C) due to the composition of cellulose and hemicellulose. WT has a higher temperature degradation zone (300- 480°C), correlating with the compositions of natural rubber, styrene-butadiene rubber and butadiene rubber. A synergism analysis by comparison of theoretical and experimental TG and DTG curve of the blend revealed an inhibitive effect on the decomposition rate on the first peak of the DTG graph (-316°C) while promoting the decomposition rate on the second peak of the DTG graph (-371°C). The activation energy of the blend (194.98 kJ/mol) is determined to be lower as compared to EFB (257.29 kJ/mol) and WT (252.92 kJ/mol) obtained through Flynn-Wall-Ozawa (FWO) method, which indicates some form of synergism between both feedstock during copyrolysis. Thus, the blending of EFB and WT has been proven to attain synergism during pyrolysis. This finding reports a viable pathway for co-processing of biomass waste (EFB) and rubber waste (WT) while potentially able to generate valuable bio-products of alternate use.