The Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) was formed in 1999 as a multi-institutional effort to develop comparative information on cellulosic biomass pretreatment options. Our prior work focused on a comparative evaluation of corn stover feedstock for five leading pretreatment technologies (dilute acid, hot water, ammonia recycle percolation, ammonia fiber explosion and lime). Our current efforts, known as the CAFI II project, have been expanded to cover hybrid poplar as the feedstock and an additional pretreatment (SO2). This paper will describe the logistical support and modeling efforts that the National Renewable Energy Lab has provided to the consortium in the CAFI II project. Model updates include a more current costing basis for the economic models, the development of a graphical user interface, and the incorporation of a woody biomass (hybrid poplar) feedstock handling system. In addition, initial pretreatment and saccharification data on hybrid poplar for each pretreatment process has been incorporated into the economic models. Progress toward the incorporation of hydrolyzate fermentation performance and the inclusion of any necessary hydrolyzate conditioning processes into the economic models will also be reported.