Nearcritical Water For Environmentally Benign Chemical ProcessingEPA Grant Number: R825325
Title: Nearcritical Water For Environmentally Benign Chemical Processing
Investigators: Eckert, Charles A. , Liotta, C. L.
Institution: Georgia Institute of Technology
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1996 through September 30, 1999
Project Amount: $180,000
RFA: Technology for a Sustainable Environment (1996) RFA Text | Recipients Lists
Research Category: Sustainability , Pollution Prevention/Sustainable Development
Description:Nearcritical water (NCW) is an environmentally-benign solvent that offers tremendous opportunities for pollution prevention for a wide variety of manufacturing processes spanning the chemical, petrochemical, pharmaceutical, and plastics industries. As a solvent in the range of 250-350 C, NCW has a density and dielectric constant similar to that of ambient acetone, which permits the dissolution and reaction of both organic and ionic species, as well as the swelling of polymers.
This project is jointly funded by NSF and EPA. The investigation will first gather, evaluate critically, expand, and model the database of thermodynamic data (primarily solubilities) for organics in NCW. Next, kinetic data will be obtained for a variety of important reactions of industrial interest. Such information will facilitate the commercialization of this technology. The studies that will be carried out with EPA funding include: oxidation of alkyl aromatics, hydrolytic depolymerization of condensation polymers, and associated thermodynamic measurements. Other reactions, that will be studied with NSF funds are: Friedel-Crafts alkylation reactions, Friedel-Crafts acylation reactions, and associated thermodynamic measurements.
Preliminary kinetic data demonstrate that one alkylation reaction can be run successfully without any added acid catalyst, and that an acylation reaction can be run with only traces of catalyst in place of the 2-3 fold molar excess of AlCl3 usually used.
As a result of these investigations, new processes will be available using "green chemistry" for sustainable development. NCW will replace many less desirable solvents, such as aromatic hydrocarbons and chlorinated compounds, it will avoid the use of polluting mineral acids and hazardous catalysts, it will permit the minimization or even the elimination of unwanted byproducts, it will provide better control of reactions which can be run homogeneously instead of heterogeneously, and it will facilitate closed processes by reuse of waste materials.