Pre-treatment technologies, and their effect on international bioenergy supply chain logistics. Techno-economic evaluation of torrefaction, fast pyrolysis and pelletisation

The pre-treatment step has a significant influence on the performance of bioenergy chains, especially on logistics. Torrefaction, pelletisation and pyrolysis technologies can convert biomass at modest scales into dense energy carriers that ease transportation and handling.Torrefaction is a very promising technology due to its high process efficiency (94%) compared to pelletisation (84%) and pyrolysis (64%).1 When torrefaction is combined with pelletisation, the product (TOP2) energy content is as high as 20.4–22.7 GJ/ton. The primary energy requirement for TOP delivery from Latin America to Rotterdam harbour can be as low as 0.05 GJ/GJ, in contrast to 0.12 GJ/GJ for pellets and 0.08 GJ/GJHHV for pyrolysis oil. TOP can be delivered to Europe at over 74 €/ton (3.3 €/GJ) and electricity could be produced as cheap as 4.4 €cent/kWhe from an existing co-firing plant. Fisher Tropisch fuel costs 6 €/GJHHV for TOP, 7 €/GJ for conventional pellets and 9.5 €/GJHHV for pyrolysis oil. Consequently, fuel production from TOP and conventional pellets is comparable to the current gasoline production cost ranging from 3 to 7 €/GJHHV and diesel from 2 to 7 €/GJHHV, depending on the oil market.3 Thus, well designed supply chains make international trade of biomass feasible from energy efficiency and economic perspective.