Biomass co-pyrolysis: Effects of blending three different biomasses on oil yield and quality

Abstract

In the present study, pyrolysis and co-pyrolysis of sugarcane bagasse, poppy capsule pulp, and rice husk were conducted in a fixed bed reactor at 550⁰C in nitrogen atmosphere. The moisture (5%–8%), ash (4%–17%), volatile matter (60%–76%), and fixed carbon analyses (11%–24%) of the utilized biomass were conducted. The decomposition behavior of biomasses due to the heat effect was investigated by thermogravimetric analysis/differential thermal analysis . In the pyrolysis of biomasses separately, the highest bio-oil yield was obtained with sugarcane bagasse (27.4%). In the co-pyrolysis of the binary blends of biomass, the highest bio-oil yield was obtained with the rice husk and sugarcane bagasse blends. While the mean bio-oil yield obtained with the separate pyrolysis of these two biomasses was 23.9%, it was observed that the bio-oil yield obtained with the co-pyrolysis of biomass blends was 28.4%. This suggested a synergistic interaction between the two biomasses during pyrolysis. It was observed that as the total ash content in the biomasses used in the pyrolysis increased, the bio-oil yield decreased, and the solid product content increased. Characterization studies of bio-oils were conducted by Fourier-transform infrared spectroscopy, gas chromatography–mass spectrometry (GC-MS), and hydrogen-1 nuclear magnetic resonance analyses. Results of these studies revealed that, all bio-oils were mainly composed of aliphatic and oxygenated compounds. The calorific values of bio-oils were determined by calorimeter bomb. Based on the GC-MS, the bio-oils with high fatty acid and its ester content also had high calorific values. The highest calorific value was 29.68 MJ kg^-1, and this was obtained by pyrolysis of poppy capsule and sugarcane bagasse blend.