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Green Chemistry Challenge: 2020 Academic Award

Professor Steven Skerlos, University of Michigan and Fusion Coolant Systems


Professor Steven Skerlos, of the University of Michigan and Fusion Coolant Systems, is being recognized for creating Pure-Cut™, an alternative to traditional metalworking fluids that uses high pressure carbon dioxide (CO2) instead of oil-based lubricants. Pure-Cut™ can improve performance and machining tool lifespan compared to traditional metalworking fluids, while greatly reducing hazards to the environment and worker health.

Summary of Technology:

Traditional metalworking fluids used for lubrication and cooling during metalworking are most commonly aqueous emulsions, which often employ hazardous additives such as surfactants and biocides that can be hazardous to workers and the environment. Even non-hazardous metalworking fluids can dissolve heavy metals during use, making the used fluid hazardous and difficult and costly to dispose of safely. Additionally, metalworking fluids often require expensive treatment to reduce biological oxygen demand, oil contamination, and nitrogen and phosphorus content. If not properly treated, used metalworking fluids can be harmful to aquatic ecosystems, for example by reducing the amount of oxygen available to some aquatic life forms.

Pure-Cut™ uses supercritical CO2, a physical state of CO2 that is between a liquid and a gas and is produced by pressurizing CO2 to high pressure. CO2 is a common byproduct of industrial processes such as combustion, fermentation, and reactions, and this waste CO2 can be used to produce supercritical CO2. Pure-Cut™ is a drop-in technology that replaces traditional metalworking fluids, using little or no oil lubricant, and can be used on most existing machine tools. The system completely eliminates most of the hazard and toxicity concerns associated with traditional metalworking fluids. Pure-Cut™ serves as a coolant as well as a lubricant because CO2 cools as pressure in the system decreases. Compared to traditional metalworking fluids, Pure-Cut™ can improve tool life and cleanliness of parts, which can reduce waste and save money for facilities adopting Pure-Cut™. The system can be adjusted to meet the needs of each process, such as by increasing pressure to increase oil solubility and cooling. Testing indicates that Pure-Cut™ performs as well as or better than other metalworking fluids across many metrics, including lubrication and cooling as well as environmental health and safety.

Pure-Cut™ was created at the University of Michigan, and Fusion Coolant Systems was launched to commercialize the technology. Manufacturers have begun to adopt Pure-Cut™ in several industries including the aerospace and medical device industries, wherever performance and cleanliness of metalworking fluids are critical.

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