This work explores the case of torrefaction of biomass at the final use location, which is a large-scale coal and biomass co-firing unit, instead of the usually researched case of upstream biomass torrefaction close to the collection area. The potential advantages of this approach include simplifying the related supply chain by removing the respective stages of pelletizing and subsequently grinding the pellets at the co-firing unit. Furthermore, process efficiencies can be gained by integrating the torrefaction process in the existing technological system. Most importantly, after torrefaction, biomass can approach similar combustion performances as that of coal, which allows burning biomass in coal burners without retrofits and fewer modifications at the fuel preparation stage. It also provides a technical solution of higher biomass co-firing ratios that would be limited without torrefaction. The tradeoff is that the long-distance logistical advantages of torrefied biomass do not apply in this case. A whole system approach is taken, considering both the biomass supply chain and the co-firing unit performance to have a better understanding of the potential benefits or drawbacks at the whole system level. The analysis includes techno-economical as well as environmental system performance aspects and focuses on a case study application of a European-based co-firing station procuring Palm Kernel Shell biomass from South Asia.
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