Softwood forest thinnings as a biomass s

Biotechnol Prog 2000, 16, 947−957 947 Softwood Forest Thinnings as a Biomass Source for Ethanol Production: A Feasibility Study for California Kiran L Kadam,*,† Robert J Wooley,† Andy Aden,† Quang A Nguyen,† Mark A Yancey,† and Francis M Ferraro‡ National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393, and Merrick and Co., 2450 South Peoria Street, Aurora, Colorado 80014 A plan has been put forth to strategically thin northern California forests to reduce fire danger and improve forest health The resulting biomass residue, instead of being open burned, can be converted into ethanol that can be used as a fuel oxygenate or an octane enhancer Economic potential for a biomass-to-ethanol facility using this softwood biomass was evaluated for two cases: stand-alone and co-located The colocated case refers to a specific site with an existing biomass power facility near Martell, California A two-stage dilute acid hydrolysis process is used for the production of ethanol from softwoods, and the residual lignin is used to generate steam and electricity For a plant processing 800 dry tonnes per day of feedstock, the co-located case is an economically attractive concept Total estimated capital investment is approximately $70 million for the co-located plant, and the resulting internal rate of return (IRR) is about 24% using 25% equity financing A sensitivity analysis showed that ethanol selling price and fixed capital investment have a substantial effect on the IRR It can be concluded that such a biomass-to-ethanol plant seems to be an appealing proposition for California, if ethanol replaces methyl tert-butyl ether, which is slated for a phaseout Introduction California is faced with several critical issues related to how its forest resources are used and managed In particular, because of suppression of forest fires, mainly during the last century, growing quantities of dead/ diseased trees, underbrush, and small-diameter green trees have accumulated in the forests, creating a severe fuel loading problem that threatens human life and property Resulting fires are so intense that they can literally turn forests into sterile deserts Air quality impacts on ecological systems and human health are also enormous as these fires emit large quantities of smoke and particulate matter, especially PM10 (particulate matter