Transportation - Engineering and Science of Biomass Feedstock Production and Provision - page 157

transport becomes more efficient and economical. In this case, centralized storage
and preprocessing centers (CSPs) are needed that store bales and transform the
feedstock into a stable, storable, blendable, and gravity-flowable form, such that the
feedstock becomes a marketable commodity. The bulk density of the particulates in
the flowable form must allow railcars to reach their volume and weight limits simul-
taneously. For instance, gondola-type coal railcars can accommodate the density of
coal in a pile, which is 850 kg m −3 , rendering the production of biomass with a simi-
lar bulk density attractive. However, to produce such a bulk density, the “in-mold”
density of the particulates comprising the bulk material needs to be over twice as
high as the bulk density, to compensate for post-compression rebound and porosity.
Overall, compression of biomass is energetically inexpensive, but the machinery
that can deliver massive amounts of highly compressed biomass is arguably expen-
sive. The same bulk form must also allow the conversion plant to efficiently pretreat
and convert the feedstock into liquid fuels.
Water transport using barges is another option for long-distance biomass trans-
portation, although the dispersion of waterways limits its application domain and
the bulk density of the material being transported must be significantly lower than
that of water. Pipeline transport, where biomass in particulate form is suspended in
a carrier fluid, has been shown unfeasible for transportation of biomass.
In the near future, several technologies must be developed/optimized to make
bioenergy a realistic alternative to fossil fuels. To integrate ongoing and future
developments, the generation of comprehensive models on strategic, tactical, and
operational levels must be pursued. These models must include the latest research
data and technologies, and be properly validated before any conclusions can be
gleaned from them.
References
1. Perlack R, Wright L, Turhollow A, Graham R, Stokes B, Erbach D (2005) Biomass as feed-
stock for a bioenergy and bioproducts industry: the technical feasibility of a billion-ton annual
supply. U.S. Department of Energy Oak Ridge National Laboratory, Oak Ridge, TN. p: 1-78
2. U.S. Department of Energy Biomass Program (2012) Feedstock supply and logistics: biomass
as a commodity. DOE/EE-0766. Available at: https://www1.eere.energy.gov/bioenergy/pdfs/
feedstocks_four_pager.pdf (verified on Dec. 13, 2013)
3. Humbird D, Davis R, Tao L, Kinchin C, Hsu D, Aden A, Schoen P, Lukas J, Olthof B, Worley M,
Sexton D, Dudgeon D (2011) Process design and economics for biochemical conversion of ligno-
cellulosic biomass to ethanol: dilute-acid pretreatment and enzymatic hydrolysis of corn stover.
U.S. Department of Energy National Renewable Energy Laboratory, Golden, CO. p: 1-114
4. Miao Z, Grift T, Hansen A, Ting K (2013) Energy requirement for lignocellulosic feedstock
densifications in relation to particle physical properties, pre-heating and binding agents.
Energy Fuel 27:588-595
5. U.S. Department of Energy (2011) U.S. Billion-ton update: biomass supply for a bioenergy
and bioproducts industry. U.S. Department of Energy Oak Ridge National Laboratory, Oak
Ridge, TN. p: 1-227
6. Hess J, Kenney K, Ovard L, Searcy E, Wright C (2009) Commodity-scale production of an
infrastructure-compatible bulk solid from herbaceous lignocellulosic biomass. Idaho National
Laboratory, Idaho Falls, ID