[Gasification] Composite Residue Logs

[Jeff Davis]

One recent innovation involves the compaction of logging residues into 
cylindrical bales called composite residue logs (CRL) or biomass bundles 
(Johansson et al, 2006). CRLs are approximately 24 inches in diameter 
(61cm) and 10 feet (3m) long.

https://www.youtube.com/watch?v=XZOoHUEgf8w


One of the most appealing aspects of CRL is, they can be handled 
similarly to round logs. Bundles are efficiently handled and transported 
with conventional equipment used for roundwood. Simple modification to 
the trailer may be required depending upon CRL length and makeup. The 
1490D Slash Bundler can produce 18 to 26 bundles per hour. Cost to 
bundle at the logging deck is approximately $11 to $14 per green ton. 
Total cost of operations to gather, bundle and deliver is $21 to $25 per 
green ton. A blend of pine and hardwood offers best economic advantages 
due to the amount of available material on ground, relative ease of 
handling and energy content. The calorific heat content has been 
measured at 10 MJ per green kg (4300 Btu per green lb) and an energy 
density of 4.5 GJ per m3. By comparison, calorific heat content of oven 
dry bundles yield 19.7 MJ per ovendry kg (8500 Btu per lb).

Slash bundling offers superior storing characteristics. Private data 
shows that seasoning bundles (storing) for 11 months reduces moisture 
content to 25 percent to 30 percent and increase energy value to 17.2 MJ 
per kg (7400 Btu per pound). The post-seasoned delivered cost is 
$

14.50 per ton. To date, approximately 67,280 m3 have been bundled 
from 15 sites in East Texas. The best comminution option appears to be 
horizontal grinders at a terminal. Grinders accept bundles easily and 
costs are minimized. Independent data show a 65-percent reduction in 
grinding costs, using a 1,500 horsepower electric motor from parasitic 
load of the electric power plant for which the bundles are serving.

http://www.extension.org/pages/26530/bundling-woody-biomass



Cheers,
Jeff