This study consisted of in-depth techno-economic analyses of biofuel upgrading processes and of whole biotrade chains. The chains encompassed the production of pyrolysis oil or pellets from biomass residues in the source regions, the transportation of the upgraded fuels internationally over long distances and the final utilisation of the fuels. The techno-economic analysis of the biofuel upgrading processes was undertaken primarily to generate techno-economic data that were needed as input data for the assessment of the biotrade chains. The evaluation of pyrolysis-oil production was deemed to be one of the most reliable assessments made to date. The estimated pyrolysis-oil production costs, e.g. below 25 EUR/MWh for stand-alone production from forestry residues, compare favourably with the current consumer-prices of heavy fuel oil in many European countries. Integration of the pyrolysis process with an industrial combined heat and power (CHP) plant would lower the production costs by more than 20%. The production of pellets was assessed to be somewhat more energy-efficient and more cost-efficient than the production of pyrolysis oil. However, the higher production costs of pyrolysis oil would be counteracted by lower costs in connection with product handling and utilisation. Four international biotrade chains were analysed in detail. The chains cover two source regions, North-Western Russia and Eastern Canada, and two traded commodities, pyrolysis oil and pellets. The chains terminate in the Netherlands where the imported biofuels are co-fired with coal in condensing power stations. The costs of the delivered biofuels were estimated to be in the range 18-30 EUR/MWh, with the costs of pellets about 25% lower than those of pyrolysis oil. The estimated electricity-generation costs displayed little dependence on the type of biofuel - pyrolysis oil or pellets - because the costs associated with the utilisation of the biofuels for co-firing are higher for the pellets. For the Canada-Netherlands chains based on ...