Dirty Oil Bottles Come Clean After a decade of development and many twists and turns, CO2-based recycling technology for HDPE motor-oil bottles is finally in the right place at the right time.

Dirty Oil Bottles Come Clean

After a decade of development and many twists and turns, CO2-based recycling technology for HDPE motor-oil bottles is finally in the right place at the right time. These bottles—2 billion of them a year in the U.S. alone—are messy to reclaim, owing to the oily residue they contain. Cleaning them with solvents or water generates hazardous waste. Now, the first commercial-scale equipment for a “clean” solution will be set up in April on a truck in Italy. It uses a process developed by Honeywell Federal Mfg. & Technologies in Kansas City, Mo., and equipment developed by Fedegari Autoclavi S.p.A. in Italy. The equipment will be marketed here by ITec International Technologies Inc. in Cincinnati.


Cleaning with gas

Liquid carbon dioxide under high pressure behaves like a solvent. It can separate oil from HDPE, allowing both the plastic and oil to be recovered in highly pure form, with no polluting byproducts. CO2 was applied to oil-bottle recycling back in the 1980s, but as a cryogenic coolant, not a solvent. The process was inefficient and never commercialized.
In the early 1990s, the U.S. Dept. of Energy began investigating liquid CO2 as an environmentally friendly degreasing agent and dry-cleaning solvent. It was applied to oil-bottle recovery by AlliedSignal (now Honeywell), which manages a DOE facility in Kansas City. Honeywell first worked with a small recycler, Blueberry Plastic Mill Inc. in Des Moines, Iowa. When Blueberry went out of business, Honeywell worked with FixCor Recycling in Heath, Ohio, which was molding pallets of recycled HDPE. FixCor got a California state grant to develop equipment for Honeywell’s patented process. But FixCor ran into financial difficulties and halted development in ’99.
Former FixCor president Gary DeLaurentiis and several others familiar with the Honeywell CO2 technology obtained a license from Honeywell to develop it. They set up ITec early last year to design and sell CO2 cleaning machinery to recyclers and oil-bottle makers worldwide.
The semi-continuous process uses multiple pressure vessels that can be small enough to mount on a truck. One or more vessels process a batch of material, while other vessels are being loaded or unloaded. Each batch takes about an hour. CO2 absorbs the oil in the liquid state and then releases it when it turns into a gas. CO2 is then recycled back into liquid. Total processing cost is about 3¢/lb, ITec says.

 

The Italian connection

Honeywell introduced fledgling ITec to Fedegari, a major European manufacturer of autoclaves and CO2-based extraction, degreasing, and dry-cleaning equipment. This was a big stroke of luck for ITec. “Fedegari’s experience dramatically shortened the development time,” says Robert Rothfuss, ITec executive v.p.
As DeLaurentiis and Rothfuss began commuting to Italy to work with Fedegari, they picked up Italian investors and customers. As it turned out, Italy had lots of pent-up interest in a mobile process to clean oil bottles, since the Italian government mandated separate collection of these bottles and strictly limited the ability to transport them because of the danger of spontaneous ignition inside a closed truck on a hot day.
By last July, Fedegari had built a prototype machine, which ITec markets as the ECO2 System. The first unit will be sold to O.P.T. Ltd. in Southern Italy, and six other Italian companies have ordered mobile systems that will travel to regional collection points such as gas stations.
—Jan H. Schut

 

In the U.S. alone, 2 billion one-quart oil bottles are discarded each year. They contain 250 million lb of HDPE and 15 million gal of oil residues. After a decade of development, a process using liquid CO2 can reclaim both the oil and plastic without generating hazardous waste.