Graham Magnetics, Inc.

Year Submitted: 2003

Process: Solvent Distillation

Industry: Electronics Manufacturing

Wastes Reduced: Solvent

Substance: MIBK

Equipment: Distillation

Location: Graham TX

No. of employees: 420

Contact: Alan Johnson

Phone: (817) 549-4500

Description:

The purpose of the MIBK Recovery/Recycle Project was to develop a production method to recover methyl isobutyl ketone (MIBK) and tetrahydrofuran (THF) from the spent solvent waste stream. Graham Magnetics' solvent recovery operations were designed to remove THF from water, and had never been used to separate MIBK and THF into re-usable solvents of acceptable quality for the stringent demands of the magnetic tape manufacturing process.
Some distillation of THF had been used to remove as much THF as possible from the resulting waste before disposal. However, the waste consistently contained 50 %-70 % MIBK, 30%-50% THF, and up to 10% water.
Because of the high cost of waste disposal and the very high cost of replacement quantities of THF and MIBK, an attempt was made to develop a production process to recover and reuse as much of each solvent as possible.
With appropriate laboratory experimentation and production efforts, a process was developed using an existing pressure column to separate water and THF from MIBK and yield a raw material stream of MIBK with less than 300 parts per million water and less than 1% THF. The resulting THF/water mixture is then separated to recover all of the THF, and the water is disposed.

P2 Application:

While the process of distillation for purification of solvents is not at all novel, the use of the specific equipment at Graham Magnetics is not in line with its original design specifications and was not anticipated to be as straight-forward as it was. This was, literally, a "You can't do that on that equipment" type of project.

Environmental Benefits:

This project has eliminated several hundred drums of hazardous liquid waste from the process of transportation and incineration, reduced human exposure to a hazardous solution, and reduced the need for production of MIBK and THF to replace solvent which had been disposed of. It is also an ongoing production process, which will allow these environmental benefits throughout the lifetime of this project.

Details of Reductions

Additional Information :

Implementation of this project has resulted in a savings of greater than 150,000 pounds of MIBK, approximately 70,000 pounds of THF, and the elimination of about 610 55-gallon drums of flammable hazardous waste, for a combined savings of more than $200,000 through December 1993. The initial investment was less than $1,000; therefore, it had a payback of a few days.

Source: TCEQ