Industry Watch: Solvent Management

Vapor degreasing is not dead,” asserts Craig Isaacs, Director of Solvent Services at the Rho Chem facility of PSC Environmental Services. Solvent services have evolved. Even in Southern California, where regulatory activities have actively fostered (some might say imposed) adoption of aqueous cleaning as an approach to achieving improved air quality, solvent cleaning remains an option. Isaacs states “our Southern California facility has been open every day since 1951. We help people get parts clean and help them stay in line with regulations. Solvent cleaning in vapor degreasers is the best approach for many applications, but it’s not as easy as it was 25 to 30 years ago.”

 

The emphasis on providing guidance and management of solvents is increasing. One expansion of a solvent service was announced during the recent Process Cleaning Expo (PCx) in Louisville, Ky. Ali Shah, business development leader for SAFECHEM North America (a subsidiary of the Dow Chemical Company) described the focus of the service as encompassing the “delivery, storage, handling, use, and safe disposal of chlorinated solvents, for precision cleaning needs.” Shah adds that “chlorinated solvents often provide the best cleaning performance if the product specific risks are adequately managed. Our service is designed to meet European standards and includes a closed loop container and transfer system that minimizes employee exposure as well as employee education and test kits to monitor solvent quality.” While initial efforts will involve traditional open-top degreasers, Shah sees efficient solvent usage as best achieved with enclosed degreasers.

 

In the U.S., open-top degreasers predominate; degreasers that have covers are still considered open top. Enclosed degreasers encompass many technologies and are generally divided into airtight or airless (vacuum) systems. While not currently required by Federal regulation, enclosed systems may be encouraged or even required in locales with poor air quality. In some instances, regulatory agencies may specify particular subsets of the technology. While they tend to cost more, they also can provide improved process control.

 

“In Europe, in the early 1990s,” explains Shah, “we started by working with those using open top degreasers. However, through OEM alliances and voluntary actions by manufacturers, enclosed systems have been adopted. Currently, especially in Germany and Switzerland, you would be hard-pressed to find an open-top system.” Shah anticipates a similar trend in the U.S. To expedite this trend, he sees education as critical. “We work with HSIA, provide case studies and work with companies. We have even initiated constructive dialogue with the EPA on the environmental compliance of our system.”

 

Vic Schuster, marketing manager specialty solvents, Hubbard-Hall Inc., indicates that 95 percent of degreasing solvent sales are for open-top systems; 5 percent are for vacuum systems. Schuster contends that “updated freeboard, cold traps, and automated hoists allow open top units to approach vacuum-like efficiency.” Schuster adds that to meet tighter regulations, “Many have converted to environmentally-friendly solvents like HFEs and HFCs. They are a growing part of our solvent business.”

 

Isaacs explains manufacturers utilize not only chlorinated solvents but also a number of HFCs, HFE, and HCFC 225; these may be used alone or as blends.   Part of solvent services involves custom recycling in a glass still for the specific user. Isaacs adds that “you have to have a lab; you have to know what you put into the still and what you get out of it.”

 

Shah adds that despite the significant capital investment in enclosed degreasers, “at the end of the day, you can reduce solvent use by over 90%. Because we constantly monitor, it is possible to get multiple years of solvent usage. Therefore, in the long run, the in-use cost is a better deal for consumers.” He notes that studies to document and quantify cost savings will be available.

 

“If the customer is willing to go to the expense of a vacuum system, it is important to keep on top of acid acceptance,” adds Isaacs. “We provide tests; we also provide a free laboratory service, where we do analysis, including ASTM methods, and provide a report. We encourage them to save the reports and to track trends. We sometimes help the customer to set limits in solvent quality parameters; sometimes these are application-specific.”

 

Isaacs emphasizes the importance of understanding the requirements of the manufacturer, adding, “I depend on repeat customers. “You have to build a foundation and to do that you have to get good information from the client that will assist in achieving safety, performance, economic and regulatory requirements.”