Implementing residue chippers on harvesting operations in the southeastern US for biomass recovery

Abstract

Implementing small residue chippers on conventional feller-buncher, skidder, and knuckleboom loader logging operations was studied in 2006 and 2007. A thinning operation fed the chipper using the same loader that handled roundwood sorting and loading, while a clearcut operation used a separate loader with the chipper. Both operations used set-out trailers to improve transportation efficiency. Production was evaluated for 65 weeks on the thinning operation and 42 weeks on the clearcut operation. Costs for producing and delivering the biomass material were estimated using an after-tax cash-flow method. The thinning operation produced an average of 32 metric tonnes (35 American tons) of biomass per day (SD: 20 tonnes and 22 tons, respectively), at an estimated cost of $18.38 per tonne delivered ($16.71/ton). The clearcut operation averaged 50 tonnes (55 tons) of biomass per day (SD: 19 tonnes and 21 tons), at a cost of $17.81/tonne ($16.19/ton). The biomass produced contained about 75% wood, with the remaining material consisting of bark, needles, and twigs. Implementing a residue chipper on a conventional operation can be economically feasible for producing biomass for an alternative fuels market, provided that it does not interfere with roundwood production. Set-out trucking aids the operation by minimizing the delay time for trucks.