2000 Progress Report: Multiphase Reactive Equilibria In CO2-Based Systems

EPA 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 Period Covered by this Report: October 1, 1999 through September 30, 2000
Project Amount: $295,000
RFA: Technology for a Sustainable Environment (1998) RFA Text |  Recipients Lists
Research Category: Sustainability , Pollution Prevention/Sustainable Development


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.

Progress Summary:

Our most important accomplish on this project in the last year has been the study of the effect of CO2 pressure on the esterification of acetic acid with ethanol. We show that the application of just 58.6 bar pressure at 333 K shifts the equilibrium conversion from 63 percent in neat solution to 72 percent in CO2. Thus, we demonstrate that CO2 is an excellent substitute solvent to replace VOC solvents, and that it can be used to alter (improve) the extent of reaction of equilibrium-limited reactions. In addition, we have made significant progress in the development of a completely reliable computation method to model the high pressure phase behavior of equilibrium-limited reactions. It allows us to reliably calculate complex phase and reaction equilibria of high pressure CO2-based systems using equation of state models. Finally, we have used some funds from this grant to explore an exciting new potential application of supercritical CO2; the extraction of solutes from ionic liquids. Ionic liquids are organic salts with negligible vapor pressure that are being explored as non-volatile replacements for organic solvents. Thus, the use of CO2 to remove products from ionic liquids represents the combination of two different environmentally benign solvent technologies. This newly-developed project has already resulted in several important publications, as listed below.

Future Activities:

The primary goal of the final year of this grant is to complete the development of the completely reliable computational method for the calculation of combined phase and reaction equilibria at high pressure. The secondary goal is to conduct an in-depth analysis of data collected by Dr. Tapan Das, a post-doctoral research associate who conducted experiments at DuPont during the first year of this grant.

Journal Articles on this Report : 8 Displayed | Download in RIS Format

Other project views: All 13 publications 9 publications in selected types All 8 journal articles
Type Citation Project Document Sources
Journal Article Blanchard LA, Brennecke JF. Esterification of acetic acid with ethanol in carbon dioxide. Green Chemistry 2001;3(1):17-19. R826734 (2000)
not available
Journal Article Blanchard LA, Gu ZY, Brennecke JF. High-pressure phase behavior of ionic liquid/CO2 systems. Journal of Physical Chemistry B 2001;105(12):2437-2444 R826734 (2000)
not available
Journal Article Blanchard LA, Brennecke JF. Recovery of organic products from ionic liquids using supercritical carbon dioxide. Industrial Engineering and Chemical Research 2001;40(1):287-292. R826734 (2000)
not available
Journal Article Gau CY, Stadtherr MA. Reliable nonlinear parameter estimation using interval analysis: error-in-variable approach. Computers & Chemical Engineering 2000;24(2-7):631-637 R826734 (2000)
not available
Journal Article Maier RW, Brennecke JF, Stadtherr MA. Reliable computation of reactive azeotropes. Computers and Chemical Engineering 2000;24:1851-1858. R826734 (2000)
not available
Journal Article Scurto AM, Lubbers CM, Xu G, Brennecke JF. Experimental measurement and modeling of the vapor-liquid equilibrium of carbon dioxide + chloroform. Fluid Phase Equilibria 2001, Volume: 190, Number: 1-2 (NOV 1), Page: 135-147. R826734 (2000)
not available
Journal Article Stradi BA, Brennecke JF, Kohn JP, Stadtherr MA. Reliable computation of mixture critical points. American Institute of Chemical Engineers Journal 2001;47:212-221. R826734 (2000)
not available
Journal Article Xu G, Scurto AM, Castier M, Brennecke JF, Stadtherr MA. Reliable computation of high-pressure solid-fluid equilibrium. Industrial & Engineering Chemistry Research 2000;39(6):1624-1636 R826734 (2000)
not available

Supplemental Keywords:

pollution prevention, green chemistry, solvent substitution., RFA, Industry Sectors, Scientific Discipline, Sustainable Industry/Business, Chemical Engineering, cleaner production/pollution prevention, Environmental Chemistry, Manufacturing - NAIC 31-33, Sustainable Environment, Technology for Sustainable Environment, Economics and Business, multiphase reactive equilibria, reaction solvent, carbon dioxide reaction systems, cleaner production, waste minimization, waste reduction, environmentally benign solvents, modeling, green process systems, chemical reaction systems, chemical manufacturing, high pressure system, solvent substitute, pollution prevention, source reduction, alternative chemical synthesis, environmentally-friendly chemical synthesis

Relevant Websites:


Progress and Final Reports:

Original Abstract
  • 1999
  • Final