The guayule (Parthenium argentatum) plant is a source of natural rubber and a possible high-energy biofuel. Herein guayule bagasse, the residual biomass after latex extraction, which accounts for 90% of the processed plant material, is modeled in a fast pyrolysis biorefining process. The simulation uses PRO/II® software and is based on data and processes used successfully in a bench scale facility. The unique 200-ton per day plant includes fast pyrolysis utilizing the tail gas reactive process followed by atmospheric separation, hydrodeoxygenation and final product separation, resulting in products similar to traditional fuels, i.e., gasoline, jet fuel and diesel. Approximately 10% of the biomass is converted to liquid fuels with 10% of this converted to gasoline, 34% jet fuel and 56 % diesel. These yields are compared to alternative feedstock and methods. The simulation results are utilized in an exergetic assessment. The depletion of exergy from its natural state (cumulative exergy demand, CExD) is considered as a measure of sustainability of the refining process. Breeding factors, measures of exergy production (the ratio of chemical exergy of the output products to the process exergy inputs), are determined. Results show, for the entire biorefining process, favorable breeding factors can possibly exceed 10, thus suggesting a favorable method of exergy production.
Estimating the specific chemical exergy of municipal solid waste