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Poster Presentation 1-09
Modeling of Carbonic Acid Pretreatment Process Using Aspen Plus
Kemantha Jayawardhana and G. Peter van Walsum
Department of Environmental Studies, Baylor University PO Box 97266, Waco, TX 76798-7266
Telephone: (254) 710-6552; Fax: (254) 710-2309; E-mail: Gpeter_van_Walsum@Baylor.edu
Use of carbonic acid instead of sulfuric acid for the pretreatment of biomass would offer environmental and process benefits for the production of renewable fuels and chemicals. The viability of this substitution depends on the effectiveness and economics of the process.
Aspen Plus software was used to create a process model of carbonic acid pretreatment. Aspen Plus is a widely accepted process simulator that provides a thorough treatment of the process thermodynamics. Because most of the physical property data for many of the key components used in the simulation of pretreatment processes are not available in the standard Aspen Plus property databases, values from an in-house database (INHSPCD) developed by the National Renewable Energy Laboratory (NREL) are used in this model. Due to unavailability of reaction kinetics, the pretreatment reactor is modeled as a “black box” reactor, making use of stoichiometric data that were generated in the laboratory. The Aspen Plus model is used to determine energy costs of carbon dioxide compression and the viability of different energy recovery options. Sensitivity results indicating economic advantages and disadvantages of the carbonic acid system, compared to water-only and sulfuric acid-based systems are discussed. A plug flow reactor model is also proposed that may be used when kinetics are developed for the pretreatment reactions.
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