Grantee Research Project Results
Final Report: Heterogeneous Catalysts for Catalytic Wet Air Oxidation
EPA Contract Number: 68D02019Title: Heterogeneous Catalysts for Catalytic Wet Air Oxidation
Investigators: Roark, Shane E.
Small Business: Eltron Research & Development Inc.
EPA Contact: Richards, April
Phase: I
Project Period: April 1, 2002 through September 1, 2002
Project Amount: $69,997
RFA: Small Business Innovation Research (SBIR) - Phase I (2002) RFA Text | Recipients Lists
Research Category: Watersheds , SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)
Description:
The objective of this research project was to determine the feasibility of a class of heterogeneous catalysts for catalytic wet air oxidation (CWAO) of organic compounds present in industrial wastewater. Inclusion of catalysts in wet air oxidation systems increases total destruction of organic compounds and reduces the severity of the operation conditions, resulting in a decrease in processing cost. The technical goals for this project were to achieve high oxidation activity and stability under relevant conditions, with minimal leaching of catalyst metals.
Eltron Research, Inc., synthesized, characterized, and evaluated a range of catalyst compositions for destruction of organic contaminants under CWAO conditions. Acetic acid was used as the target organic contaminant because it is one of the more refractory pollutants and a common by-product of incomplete oxidation of larger organic compounds. In a typical experiment, 300 mL of a 1,000 mg/L aqueous acetic acid solution was placed in a reaction vessel with 3 g of catalyst. Removal of total organic carbon (TOC) was measured as a function of time at 200ºC and 300 psi with continuous stirring and oxygen flow. Selected catalysts were tested for lifetime, leaching, and structural changes under operating conditions. The most promising compositions were tested supported on commercial ceramic saddles.
Summary/Accomplishments (Outputs/Outcomes):
Catalysts evaluated during this project demonstrated high activity for destruction of acetic acid in water under CWAO conditions. The most active metal oxide catalyst achieved 70 percent TOC removal after 50 minutes at 200ºC and 300 psi, and nearly complete removal after 125 minutes. Catalysts containing Pt were more active, and achieved complete TOC removal after 50 minutes under identical conditions. These catalysts did not leach significantly into the water samples and did not demonstrate structural changes during use. Preliminary lifetime measurements indicated that the catalysts were reusable, and standard commercial ceramic saddles worked very well as structural supports. Both metal oxide and Pt analogs outperformed commercial 1 percent Pt/Al2O3 in side-by-side tests.
Conclusions:
Results from this Phase I research project demonstrated the potential of a class of catalysts for CWAO. These findings suggest that this technology has good potential for commercial success, and this conclusion was supported by a commercialization assessment performed by an outside company. The Phase I results clearly indicated the most promising ranges of compositions, and future work must focus on composition optimization and producing catalysts in appropriate forms for commercial CWAO. A patent application (Roark SE. Application of catalysts for catalytic wet-air oxidation of organic compounds) was filed on September 25, 2002, as a continuation-in-part to Patent Number 6,458,741.
Supplemental Keywords:
wet air oxidation, water treatment, hydrothermal, catalyst, total organic carbon, pollutants, metal oxide, SBIR, Scientific Discipline, Water, Chemical Engineering, Environmental Chemistry, Wastewater, Chemistry, Environmental Engineering, Engineering, Chemistry, & Physics, wastewater treatment, industrial wastewater, wastewater remediation, oil/water emulsions, alternative technology, wastewater discharges, aqueous waste, aqueous waste stream, catalytic wet air oxidationThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.