Tree ring counts indicated that aboveground portions of these trees were 15e35 years old. Tree branches (5e10 cm diameter) were chain sawed down and then passed through a Vermeer wood chipper. Leaf and small twigs were removed from branches before chipping. Chipped material was then passed through a motorized sieve system to separate into different particle sizes. No attempt was made to separate heartwood, sapwood and bark in either species. At the time of harvest, fresh wood moisture content was between 30 and 45% [Ansley, unpublished data]. During the chipping and sieving process, wood moisture content declined to between 10
and 20%. Wood chips were subsequently stored in cellulose bags and transferred to College Station for gasification trials.