1. Abstract:  Estimated percentages of cellulose, hemi-cellulose, lignin, and other minor proximate components in biomass materials.  Analyzed by elemental ratios and experimental heating values. Introduction:  Previous research limited to lengthy laboratory techniques.  A simpler approach; using heating values and molecular group contributions.  Basis for the computer code is a geometric relationship of elemental ratios plotted graphically.  Majority of biomass material falls in the area between the lignin and cellulose points.  Deviation from the line connecting lignin and cellulose results from other compounds in the sample.  Different structures of lignin exist, represented by the cluster of three lignin points on the graph.  Used the relative amounts of hetero atoms in a sample to estimate the percentage of certain more complex components.  Percentage protein was determined by the established formula: Mass% Nitrogen * 6.25 = Mass% Protein 1  Basic components such as cellulose, hemi-cellulose and lignin have distinct heating values, which determined a total heating value. H f Cellulose: 976 kJ/kmol 2 H f Lignin: 1593 kJ/kmol 2 H f Hemi-Cellulose: 762 kJ/kmol 2 Analysis:  Visual basic program to calculate the percentages of cellulose, lignin, protein, and other extractives.  Biobank database 3 of elementary analysis supplied the needed elemental data.  Cellulose and lignin percentages were determined using the areas formed on the hydrogen/carbon vs. oxygen/carbon graph by lines drawn from the biomass to the points for cellulose, lignin, and a third compound.  Third compound was taken as a lipid or protein because a large portion of the unknown extractives were expected to have a similar composition.  Hemicellulose and cellulose concentrations differentiated by the following estimates: Hardwood/Grasses: 63% Cellulose, 37% Hemicellulose 4 Softwood : 53% Cellulose, 47% Hemicellulose 4  Gross calorific values checked the validity of the findings by multiplying heats of combustion by mass percentages.  Predicted GCVs were then compared with experimentally determined gross calorific values. Results: Conclusions:  The type of analysis provides more accurate estimates for those biomass materials with smaller amounts of exotic compounds and those with limited degradation of proximate compounds.  This program could prove to be an effective method to screen large numbers of biomass materials for a desired proximate composition. This could be followed by a more exact laboratory analysis. Gavin George Dr. Larry Baxter Dept. of Chemical Engineering, Brigham Young University, Provo, Utah Acknowledgements:  US DOE/EE Biopower Program  National Renewable Energy Laboratory 1 - U.S Department of Energy, Office of Transportation Technologies, Biofuels, http://www.ott.doe.gov/biofuels/glossary.html#P 2 - Development of an ASPEN Plus Physical Properties Data base for Biofuels Components, Robert J. Wooley Victoria Putsche, National Renewable Energy Laboratory, http://www.afdc.doe.gov/pdfs/3955.pdf 3 - BioBank version 2.4, BIOS consulting, Graz, Austria 4 - Emissions of Rural Wood-Burning Cooking Devices, Grant Ballard-Tremeer, Appendix D Wood combustion, http://www.energy.demon.nl/thesis/AppdxD.htm  The user interface of the program: Hardwood: 29 compounds tested Average Values %Cellulose = 41.3% %Hemicellulose= 32.2% %Lignin= 21.0% %Protein= 0.025% %Other= 2.4% Hardwood: (Scurlock 5 ) Average Values %Cellulose = 45.0% %Hemicellulose= 30.0% %Lignin= 20.0% %Protein= n/a% %Other= 5.0% Softwood: 5 compounds tested Average Values %Cellulose = 37.7% %Hemicellulose= 20.1% %Lignin= 26.0% %Protein= 0.011% %Other= 16.2% Softwood: (Scurlock 5 ) Average Values %Cellulose = 42.0% %Hemicellulose= 21.0% %Lignin= 26.0% %Protein= n/a% %Other= 11.0% Grass: 183 compounds tested Average Values %Cellulose = 36.5% %Hemicellulose= 32.4% %Lignin= 22.8% %Protein= 0.056% %Other= 9.67% Grass: (Scurlock 5 ) Average Values %Cellulose = 30.0-50.0% %Hemicellulose = 25.0-40.0% %Lignin= 15-25.0% %Protein= n/a% %Other= 5.0-15.0% 1. 5 - “Bioenergy Feedstock Characteristics”, Jonathan Scurlock, Oak Ridge National Laboratory, Bioenergy Feedstock Development Programs, http://bioenergy.ornl.gov/papers/misc/biochar_factsheet.htmlz