Environmental Engineering Reference
In-Depth Information
taBle 7.2
transportation options for Biomass Feedstocks
transportation options
description
Bags, totes, and bales
Bags and totes are commonly used for wood pellets, pucks, or briquettes. Small bags (15-30
kg) can be stacked on pallets for retail sale, whereas totes (1 m
3
; 100-500 kg) are more
appropriate for commercial/industrial operations. Bales can be in a small or large format,
with small bales typically rectangular and large bales round or cubed. All of these units are
typically transported by flat-bed truck or rail, but they can also be containerized for long
distance and shipping transport.
Flat-bed trailer
Flat-bed trailers are widely available and work well for a diverse range of materials and
applications. They can be used for palleted bags, totes, or bales and can also be used to
transport large logs. Forklifts or grapples are needed for loading/unloading.
Dump trucks and tipper
trailers
Dump trucks are also commonly used for transport of many bulk commodities. This system
can be appropriate for woodchips, pellets, and various other forestry, agricultural, and
industrial biomass feedstocks that are sufficiently dense. Biomass is delivered by gravity,
dumping the load into receiving hoppers or storage bunkers, thus minimizing the need for
additional handling or equipment.
Container and container
truck
Containers can be used for transport and storage. Intermodal trailers can be used for truck,
rail, and ship and are an efficient way to transport biomass long distances if it is suitably
densified. Modified containers can also be used for biomass storage on site, but require
sufficient ventilation and a pneumatic delivery system or other mechanism for fuel
unloading.
Walking floor trailer
Walking floor trailers have a hydraulic floor that pushes material out for rapid unloading. They
are an efficient delivery system for woodchips in bulk and would also be appropriate for
other loose but dense biomass. Direct rapid loading is possible from high-throughput
woodchip blowers, other pneumatic mechanisms, or overhead through retractable roofs.
Rail
Biomass can be transported via rail in boxcars or flat-bed cars (bags, totes, or bales), hopper
cars (bulk sawdust, chips, or pellets), or containers. Rail transport is highly energy-efficient
and low-cost where available.
Ship and barge
Palleted bags, totes, and bales can also be transported by barge or ship, but containers and
bulk transport in holds will typically be lower cost. Water is the most energy-efficient means
of very long-distance transport.
Pipeline
Although usually used for liquids or gases, pipelines can also be a low-cost means of moving
woodchip slurries long distances in high volumes (ยป500,000 Mg/year). Like rail and ship,
pipelines require terminals at both ends of transport and thus may be more appropriate for
plantation feedstock production and large end-users.
Source:
Biomass Energy Centre, available at http://www.biomassenergycentre.org.uk (accessed February 6, 2011), 2011;
Kumar, A., Cameron, J., and Flynn, P.,
Appl Biochem Biotechnol.,
113, 27-39, 2004; Uslu, A., Faaij, APC., and
Bergman, PCA.,
Energy
, 33, 1206-1223, 2008.
short-term on-site stock level (e.g., a few days' supply) can be stored, small processing equipment
can be used, and more regular, evenly spread deliveries of biomass will be required. Thus, low
levels of stockholding at the facility will increase the importance of reliable and flexible transport
services (Allen et al. 1998; Sokhansanj and Fenton 2006; Eksioglu et al. 2009; Frisk et al. 2010).
In contrast, a facility with a large capacity permits prolonged storage of larger on-site stock levels,
and cost advantages are made possible by economies of scale and use of large, powerful processing
equipment. In this case, transportation of biomass can be arranged less frequently and typically in a
less expensive, larger load size. In some cases, trains may be involved to support the transportation
to and from storage depots, offering a relatively less expensive transportation alternative to trucks.
However, prolonged storage of biomass creates costs in the form of cost of capital invested in the
biomass feedstock that remains unused during storage periods. This cost represents the interest
