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Thermochemical processing of biomass produces a solid product containing char (mostly carbon) and ash. This char can be combusted for heat and power, gasified, activated for adsorption applications, or applied to soils as a soil amendment and carbon sequestration agent. The most advantageous use of a given char depends on its physical and chemical characteristics, although the relationship of char properties to these applications is not well understood. Chars from fast pyrolysis and gasification of switchgrass and corn stover were characterized by proximate analysis, CHNS elemental analysis, BrunauerEmmet-Teller (BET) surface area, particle density, higher heating value (HHV), scanning electron microscopy, X-ray fluorescence ash content analysis, Fourier transform infrared spectroscopy using a photo-acoustic detector (FTIR-PAS), and quantitative 13 C nuclear magnetic resonance spectroscopy (NMR) using direct polarization and magic angle spinning. Chars from the same feedstocks produced under slow pyrolysis conditions, and a commercial hardwood charcoal, were also characterized. Switchgrass and corn stover chars were found to have high ash content (32-55 wt %), much of which was silica. BET surface areas were low (7-50 m 2 /g) and HHVs ranged from 13 to 21 kJ/kg. The aromaticities from NMR, ranging between 81 and 94%, appeared to increase with reaction time. A pronounced decrease in aromatic CÀ ÀH functionality between slow pyrolysis and gasification chars was observed in NMR and FTIR-PAS spectra. NMR estimates of fused aromatic ring cluster size showed fast and slow pyrolysis chars to be similar ($7-8 rings per cluster), while highertemperature gasification char was much more condensed ($17 rings per cluster).

Printed on paper containing at least 50% wastepaper, including 10% post consumer waste.iii ForewordThe purpose of this techno-economic analysis is to determine the economics of converting biomass to transportation fuel components via fast pyrolysis. Every effort has been made to place this analysis on an equivalent basis with other biomass conversion technologies analyzed in separate reports by using common assumptions. The process design and parameter value choices underlying this analysis are exclusively based on public domain literature. Accordingly, the results should not be interpreted as optimal performance of mature technology, but as the most likely performance given the current state of public knowledge. Executive SummaryThe purpose of this study is to develop techno-economic models for assessment of the conversion of biomass to valuable fuel products via fast pyrolysis and bio-oil upgrading. Liquefaction of biomass by fast pyrolysis and subsequent upgrading of the resulting pyrolysis oil (bio-oil) by hydrotreating and hydrocracking-refinery processes that use hydrogen to remove impurities and break large molecules down to smaller ones-is a promising means for producing renewable transportation fuel. The upgrading process assessed in this study produces a mixture of naphtha-range (gasoline blend stock) and diesel-range (diesel blend stock) products. This study develops techno-economic models and uses them to analyze the economics of two scenarios. In one, hydrogen needed for the upgrade process is produced onsite by reforming biooil. In the other, the hydrogen is purchased from an outside source.Both scenarios are based on a fast pyrolysis plant with bio-oil upgrading using 2,000 metric tons per day (MT/day) of corn stover feedstock. Major assumptions made for this analysis match those of companion analyses for producing transportation fuel from biomass via biochemical and gasification technologies. Product value-defined as the value of the product needed for a net present value of zero with a 10% internal rate of return-is first calculated for a mature industry or n th plant and then adjusted for a pioneer plant or one of the first of its kind.The study results indicate that petroleum fractions in the naphtha distillation range and in the diesel distillation range are produced from corn stover at a product value of $3.09/gal ($0.82/liter) with onsite hydrogen production or $2.11/gal ($0.56/liter) with hydrogen purchase. These values correspond to a $0.83/gal ($0.21/liter) cost to produce the bio-oil. Based on these n th plant numbers, product value for a pioneer hydrogen-producing plant is about $6.55/gal ($1.73/liter) and for a pioneer hydrogen-purchasing plant is about $3.41/ gal ($0.92/liter). Although these results suggest that pyrolysis-derived biofuels are competitive with other alternative fuels, the technology is relatively immature, resulting in a high level of uncertainty in these estimates.Capital costs for integrated hydrogen production are estimated at $287 million with a fuel yield of 35...