Science Inventory

TREATMENT AND PRODUCT RECOVERY: SUPERCRITICAL WATER OXIDATION OF NYLON MONOMER MANUFACTURING WASTE

Impact/Purpose:

The University of Texas at Austin (UT) proposes to conduct a unique research study (Phases II and III) leading to the development of a commercially viable waste treatment and product recovery facility. The previous study (Phase I), supported by grants from Gulf Coast Hazardous Substance Research Center (GCHSRC) and industries, successfully demonstrated that the supercritical water oxidation (SCWO) process was effective in treating Nylon monomer manufacturing wastewater and recovering inorganic electrolytes. Specifically, the SCWO process achieved greater than 99% of organic carbon conversion, provided a unique opportunity to recover greater than 90% of boron (as boric acid), and demonstrated removal of greater than 99% of the sodium (as sodium carbonates). However, experimentation is required to develop an effective reactor for continuous removal of inorganic salts from supercritical. water.

The proposed treatment and recovery concept has important economic considerations. A preliminary cost benefit analysis clearly demonstrated the attractiveness of this new concept. This analysis included three cases: (A) SCWO; (B) deep-well injection; and (C) a combination of reverse osmosis and incineration. The calculation was based on (1) a 11,000 lb/hr waste stream containing 2% sodium, 2% carbon, and 0.17% boron (as s6dium carboxylates and borate); (2) 10 years of plant life; (3) 8% interest rate; and (4) 10% salvage value. The net costs (capital recovery + operating costs - credit) were $0.27, $4.93, and $2.75 for processing 1000 pounds of the waste by Cases A, B, and C, respectively. The low net cost for Case A was the result of $1,369,000 per year credits for recovering boric acid, sodium carbonate, and steam/water from the SCWO process. Although deep-well injection is currently used for such disposal, this method does not recover resources, and therefore, has the highes

The University of Texas at Austin (UT) proposes to conduct a unique research study (Phases II and III) leading to the development of a commercially viable waste treatment and product recovery facility. The previous study (Phase I), supported by grants from Gulf Coast Hazardous Substance Research Center (GCHSRC) and industries, successfully demonstrated that the supercritical water oxidation (SCWO) process was effective in treating Nylon monomer manufacturing wastewater and recovering inorganic electrolytes. Specifically, the SCWO process achieved greater than 99% of organic carbon conversion, provided a unique opportunity to recover greater than 90% of boron (as boric acid), and demonstrated removal of greater than 99% of the sodium (as sodium carbonates). However, experimentation is required to develop an effective reactor for continuous removal of inorganic salts from supercritical. water.

The proposed treatment and recovery concept has important economic considerations. A preliminary cost benefit analysis clearly demonstrated the attractiveness of this new concept. This analysis included three cases: (A) SCWO; (B) deep-well injection; and (C) a combination of reverse osmosis and incineration. The calculation was based on (1) a 11,000 lb/hr waste stream containing 2% sodium, 2% carbon, and 0.17% boron (as s6dium carboxylates and borate); (2) 10 years of plant life; (3) 8% interest rate; and (4) 10% salvage value. The net costs (capital recovery + operating costs - credit) were $0.27, $4.93, and $2.75 for processing 1000 pounds of the waste by Cases A, B, and C, respectively. The low net cost for Case A was the result of $1,369,000 per year credits for recovering boric acid, sodium carbonate, and steam/water from the SCWO process. Although deep-well injection is currently used for such disposal, this method does not recover resources, and therefore, has the highe

Description:

EPA GRANT NUMBER: R822721C569
Title: Treatment and Product Recovery: Supercritical Water Oxidation of Nylon Monomer Manufacturing Waste
Investigator: Earnest F. Gloyna
Institution: University of Texas at Austin
EPA Project Officer: S. Bala Krishnan
Project Period: September 1, 1998 - August 31, 1999
Project Amount:
RFA: Gulf Coast Hazardous Substance Research Center (Lamar University)
Research Categories: Hazardous Waste/Remediation, Targeted Research

Description

Objective:

The University of Texas at Austin (UT) proposes to conduct a unique research study (Phases II and III) leading to the development of a commercially viable waste treatment and product recovery facility. The previous study (Phase I), supported by grants from Gulf Coast Hazardous Substance Research Center (GCHSRC) and industries, successfully demonstrated that the supercritical water oxidation (SCWO) process was effective in treating Nylon monomer manufacturing wastewater and recovering inorganic electrolytes. Specifically, the SCWO process achieved greater than 99% of organic carbon conversion, provided a unique opportunity to recover greater than 90% of boron (as boric acid), and demonstrated removal of greater than 99% of the sodium (as sodium carbonates). However, experimentation is required to develop an effective reactor for continuous removal of inorganic salts from supercritical. water.

The proposed treatment and recovery concept has important economic considerations. A preliminary cost benefit analysis clearly demonstrated the attractiveness of this new concept. This analysis included three cases: (A) SCWO; (B) deep-well injection; and (C) a combination of reverse osmosis and incineration. The calculation was based on (1) a 11,000 lb/hr waste stream containing 2% sodium, 2% carbon, and 0.17% boron (as s6dium carboxylates and borate); (2) 10 years of plant life; (3) 8% interest rate; and (4) 10% salvage value. The net costs (capital recovery + operating costs - credit) were $0.27, $4.93, and $2.75 for processing 1000 pounds of the waste by Cases A, B, and C, respectively. The low net cost for Case A was the result of $1,369,000 per year credits for recovering boric acid, sodium carbonate, and steam/water from the SCWO process. Although deep-well injection is currently used for such disposal, this method does not recover resources, and therefore, has the highes

t net cost. Furthermore, based on a capital investment of $4,500,000 and a baseline treatment cost of $4/1000 lbs of waste, roughly equivalent to the operating cost for deep-well injection, the return of investment for the SCWO process is $2,200,000 and the investment has a payback period of 4.5 years.

Approach:

This proposed two-year, technology development and transfer effort involves four tasks: (A) experimentation directed to reactor development, design, and testing; (B) overall process development and design; (C) pilot-plant validation of process design concepts; and (D) economic assessments. GCHSRC is requested to provide $56,720 for Phase H (Tasks A and B). Subject to successful, laboratory-scale demonstration of a SCWO reactor system, an additional $56,720 will be needed for Phase III (Tasks C and D). Matching funds will be derived from industry ($50,000/year) and UT ($6,900/year) for Phases II and III, respectively.



Supplemental Keywords: Water, TREATMENT/CONTROL, Sustainable Industry/Business, Scientific Discipline, Wastewater, Water Pollution Control, Chemical Engineering, Technology, Environmental Engineering, Environmental Chemistry, New/Innovative technologies, Economics and Business, industrial wastewater, wastewater treatment, inorganic electrolyte recovery, clean technologies, emissions control technology, supercritical water oxidation, aqueous waste stream, effluents, hazardous liquid waste, monomer manufacturing wate

Progress and Final Reports:
1999 Progress Report

URLs/Downloads:

1999 Progress Report

URL

Record Details:

Record Type:PROJECT( ABSTRACT )
Start Date:09/01/1998
Completion Date:08/31/1999
Record ID: 57864