Multiphase Reactive Equilibria In CO2-Based SystemsEPA Grant Number: R826734
Title: Multiphase Reactive Equilibria In CO2-Based Systems
Investigators: Brennecke, Joan F. , Stadtherr, Mark A.
Institution: University of Notre Dame
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1998 through September 30, 2001
Project Amount: $295,000
RFA: Technology for a Sustainable Environment (1998) RFA Text | Recipients Lists
Research Category: Sustainability , Pollution Prevention/Sustainable Development
Description:The objective of this work is to develop experimental, modeling, and computational methodologies that will facilitate the design and evaluation of equilibrium limited chemical reaction processes using supercritical carbon dioxide as an environmentally benign replacement solvent. Supercritical carbon dioxide, which is non-toxic, non-flammable, readily available and inexpensive, has been shown to be a viable reaction medium for a wide variety of reactions. However, the phase behavior, which determines the conditions needed to ensure single phase operation, is frequently the limiting factor. For equilibrium limited reactions it is a combination of phase and reaction equilibrium limitations that will determine operating pressures and temperatures and, thus the viability of CO2 as a replacement solvent. Reliable measurement, modeling and computation of high pressure multiphase reaction equilibrium is needed for the design and evaluation of these systems.
Approach:The multifaceted approach we plan includes: 1) measurement of the high pressure single phase and multiphase reaction equilibria of several representative systems that use CO2 as a solvent, 2) modeling of the phase and reaction equilibria with appropriate equation of state models, 3) development of a new and completely reliable computational method to solve multiphase reaction equilibrium problems and 4) application of the new computational method to model and predict the combined phase and reaction equilibria of the systems studied experimentally. The systems chosen for investigation will include both simple model reactions, as well as ones of significant industrial importance. Some of the experimental measurements will be performed at the DuPont Experimental Station in collaboration with Drs. Keith W. Hutchenson and Frank E. Herkes.
Expected Results:The expected results of the proposed research are the development of an experimental methodology that uses minimal experimental effort to obtain necessary model information, and the development of a completely reliable computational method to determine simultaneous phase and reaction equilibria in high pressure systems. The net result of these accomplishments will be a better understanding of equilibrium limited CO2-based reaction systems, and the ability to better scale-up and optimize this technology for commercial use.
Improvement in Risk Assessment or Risk Management: By allowing the reliable design, optimization and evaluation of CO2-based reaction processes, this research will expand the potential for substituting carbon dioxide for hazardous organic solvents that are currently used widely in the chemical industry. The large-scale use of CO2 as a replacement solvent for reactions will represent a significant advancement of environmentally benign processing in the chemical manufacturing industry.