 |
Do you agree with new policy that reduces taxes for US producers of renewable chemicals?
|
 |
Biofuels International Conference 2013
11 September 2013 - 12 September 2013
Ramada Plaza, Antwerp, Belgium
Read more >> |
ILTA
3 June 2013 - 5 June 2013
Houston, Texas |
21st European Biomass Conference and Exhibition
3 June 2013 - 7 June 2013
Copenhagen, Denmark |
Renewable Energy World Europe
4 June 2013 - 6 June 2013
Messe Wien, Vienna, Austria |
|
|
|
|
|
Volume 3, Issue 6
Feature: Size matters |
A crucial factor when moving biomass is the bulk density – weight is rarely a problem. Loose plant-based biomass has a low bulk density ranging from 50 to 130 kg/m3 depending on the plant species, particle density, and particle size. Particle size makes a huge difference, although tree trunks and sawdust might have the same particle density, you can pack sawdust tighter than a stack of logs. Much the same applies to a heap of straw, peanut shells or any other plant waste. Wood chips have a bulk density of around 200-400 kg/m3 which is less than tightly stacked logs but substantially better than ‘brash’- the loose unwieldy heap of branches and twigs left after the logs have been removed from a forest. Biomass densifi ed into bales and cubes is even better with bulk density in the range 120-700kg/m3. Not only that, handling is easier too. The handling properties of pellets and cubes are similar to those of grains. Well established methods and conventional bulk handling equipment can be used to handle pelleted and cubed biomass. Loose straw or corn stover is much less dense than wood with a bulk density of around 15-45 kg/m3, but simply baling it in the fi eld increases that to 100-190 kg/m3 whilst shredding and pelletising it increases the density to 550-700 kg/m3. An important part of densifi cation is removing water from the biomass. This lowers the physical density of the material but raises the energy density. It also means industry players do not waste energy by transporting water.
|
|
|
|
|
|
|
