Valorisation of residual biomass by pyrolysis: influence of process conditions on products

• Published in: Sustainable energy & fuels 2024-01, Vol.8 (2), p.379-396
• Main Authors: Vilas-Boas, A. C. M, Tarelho, L. A. C, Oliveira, H. S. M, Silva, F. G. C. S, Pio, D. T, Matos, M. A. A
• Format: Article
• Language: English
• Subjects: Agroforestry; Biomass; Carbon content; Charcoal; Energy sources; Eucalyptus; Fixed bed reactors; Fixed beds; Forest biomass; Heating; Heating rate; Industrial production; Oils & fats; Pyrolysis; Sawdust; Thermal energy
• ISSN: 2398-4902; 2398-4902
• DOI: 10.1039/d3se01216f

In the context of sustainable residual biomass management, this work explores the pyrolysis process of residual biomass using a bench-scale fixed bed reactor. The main focus is to comprehensively analyze the effects of diverse forest and agroforestry biomass, pyrolysis temperature (350, 450 and 550 °C) and heating rate (2, 10 and 30 °C min −1 ) on the yield of the products biochar, bio-oil and permanent gas, and on the composition of biochar and permanent gas. This analysis provides a valuable collection of insights to support the advancement of pyrolysis projects and their expansion into industrial production, facilitating the creation of versatile products. The study showed that the biochar, bio-oil and permanent gas yields were between 0.22 and 0.47, 0.26 and 0.59 and 0.17 and 0.41 kg kg −1 dry biomass, respectively. The pyrolysis of olive pomace has the maximum biochar yield, that of eucalyptus sawdust has the maximum bio-oil yield, and that of giant reed has the maximum permanent gas yield. The increased temperature led to a decreased biochar yield and an increased bio-oil yield. The increased heating rate led to a decreased biochar yield and an increased bio-oil yield. Biochar has a carbon content above 0.7 kg kg −1 dry ash free, with an LHV between 24.2 and 30.5 MJ kg −1 dry biochar, suggesting potential for soil enrichment and the energy vector. Permanent gas has an LHV between 5.4 and 9.7 MJ Nm −3 , and seems useful as a thermal energy source to support the pyrolysis process. In the context of sustainable residual biomass management, this work explores the pyrolysis process of residual biomass using a bench-scale fixed bed reactor.