NSF/EPA Technology for a Sustainable Environment: Superheated Water and Steam Degreasing of Working Stocks, Parts, and Equipment in Machining, Manufacturing and Production

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

This NSF/EPA Technologies for a Sustainable Environment project will identify and develop an environmentally benign, innovative, efficient, low-cost technique for degreasing working stocks, parts and other metal surfaces using superheated water and steam. By utilizing the unique properties of pure superheated water for this purpose it is anticipated that the current use of conventional hazardous organic and alkaline solvents will be markedly reduced. The research will demonstrate that superheated water and/or steam (SHWS) will provide the same level of degreasing as conventional solvents. Optimum superheated water temperatures for effective degreasing will be correlated to quantifiable parameters of grease components, such as dropping point, thickener type and grease condition. Alternating sequences of superheated water and steam treatments will be tailored to specific types of grease to provide optimal degreasing effectiveness. The alternating sequence schemes will be coupled with reactor configurations and mixing scenarios that will enhance the SHWS degreasing process. It is expected that the energy costs for heating water and steam will be more than balanced by the reduction of treatment and disposal costs below those associated with traditional organic and alkaline solvent systems. For difficult degreasing situations that require solvent modifiers such as surfactants and chelating agents, superheating the water will allow minimization of these additives, reducing direct costs and wastewater problems. This NSF sponsored project, complemented by similar support from EPA for this research, is expected to result in significant reduction of solvent use in industrial parts cleaning operations.