Inherent process variations between fast pyrolysis technologies: A case study on Eucalyptus grandis

• Lignocellulosic composition variations within the woody feedstock may occur.
• The quality of FP liquid at any scale depends on the vapour-solid separation system efficiency.
• Small feed capacity FP plant produced the highest organics content.
• Large feed capacity FP plant provided high-energy density carriers as slurry-like biosyncrude.
• Large feed capacity FP is likely to be process related.

Fast pyrolysis of Eucalyptus grandis was carried out using different reactor configurations and scale setups, a 0.1 kg/h bubbling fluidised bed (BFB) reactor, a 1 kg/h BFB reactor and a 10 kg/h twin-screw reactor. The influence of lignocellulosic composition, process configuration (reactor configuration, separation and condensation system) and their feed capacity on yields and quality of pyrolysis products was discussed. The increasing reactor scale study had constraints such as the availability of biomass feedstock with inherent changes in the chemical composition and the practicality of the condensation chain. Although the methods employed for phase separation and liquid collection differ from plant to plant limiting the repeatability of results, it was clearly identified that the implementation of efficient solid separation and use of mineral oil as the coolant system were crucial aspects of the mass production of organics. These results suggest that yields and quality of fast pyrolysis at a larger scale are all process-related rather than feedstock conditioned. A comparison of energy balances indicated that fast pyrolysis retained the same energy yield at scales of 1 and 10 kg/h.