Transportation

Transportation of lignocellulosic biomass feedstock is an important task within a biomass-based energy provision system. The distributed availability of low-density feedstock makes this operation highly challenging. The proposed aim to replace a large percentage of fossil fuels with renewable lignocellulosic bioenergy sources by the year 2030 [1, 2] will require adaptation and possibly renovation of the existing transportation infrastructure. The complexity of the biomass provision system will be further increased as compared to the current system since the biomass feedstock portfolio will consist of a range of energy crops, grown in various locations with unique climates and transportation infrastructures. Ideally, biomass would be preprocessed into a gravity-flowable particulate bulk form that allows utilization of and expanding upon the existing transportation infrastructure of agricultural bulk products such as corn and soybean. Such a form would require size reduction of feedstock, which is energetically expensive, followed by compression. To optimize long-distance transport, the bulk density of this feedstock would ideally be as high as that of coal in railcars. This would require very high in-mold particulate densities of the feedstock generated by machines with very high throughput. Even if this goal could be achieved, it is currently not clear what the effect of such a highly densified material form on the conversion efficiency would be. Finally, apart from technical challenges in producing the ideal form of biomass from a provision and conversion perspective, there is a huge challenge in the mere scale of the proposition: If the goal set by the US government of replacing 30 % of current fossil fuels by 2030 is to be reached, the annual transported volume of biomass would be three times that of the 2011 US corn yield. This chapter reviews the literature on research that addresses biomass feedstock provision including transportation and identifies challenges that must be addressed in the near future.