Thermal behaviour and synergistic effect analysis of co-pyrolysis of coconut copra and eggshell for biofuels production

Abstract

This research investigates the thermal behaviour and synergistic effect of co-pyrolysis of coconut copra (CC) with eggshell (ES) for biofuels production using thermogravimetric analysis and a lab-scale tubular fixed-bed pyrolyzer at various CC:ES ratios. The TGA-DTG curves revealed that a CC:ES ratio of 1:1 had the highest total weight loss of 96 wt% and a degradation peak of 22 wt%/min. The co-pyrolysis of CC and ES using a tubular fix-bed reactor at temperatures between 350 °C and 600 °C showed that a maximum bio-oil of 74 wt% was produced from CC:ES ratio of 1:1 at 450 °C.I It was observed that as the mass of ES was greater than CC, the bio-oil yield decreased while biochar and pyrolysis gas yields increased. The synergistic effect of higher volatile matter in CC and higher ash content in ES had significantly altered the pyrolysis reactions and yielded different amount of pyrolysis products at different ratios of CC:ES. The presence of high metal content dominated by Ca in ES influenced the devolatilization behaviour of the feedstocks resulting in the increase of bio-oil yield at the suitable ratio of CC:ES. These findings also revealed that the main targeted pyrolysis products can be fine-tuned with the ratio of CC:ES.