Contact: Becky Rische(512) 471-7272Date: April 5, 2001
UT Austin engineers working to improve soil cleanup process
AUSTIN, Texas -- Engineers at The University of Texas are working with a Massachusetts-based startup firm to improve a leading-edge technology for cleaning up contaminated soil. The arrangement will net the University at least $125,000 per year.
The toxic cleanup process was the brainchild of several engineers, including a UT Austin graduate who went on to work for Houston-based Shell Technology Ventures Inc., a Shell Oil Co. subsidiary. Their toxic cleanup process already is in use at U.S. Superfund sites and has proven effective for a wide range of soil contaminants from PCBs and pesticides to by-products of the petroleum industry. It is known as In-Situ Thermal Destruction (ISTD).
Last year, Shell Technology Ventures donated a collection of patents to the process to UT Austin, a gift valued at $80 million. UT Austin's Center for Petroleum and Geosystems Engineering, in turn, recently signed a licensing arrangement with Terra Therm Inc. The arrangement allows TerraTherm, a venture company that conducts soil cleanup on a national scale, to use the technology while UT Austin faculty and students research and further develop it. TerraTherm, headquartered in Fitchburg, Mass., has a major test facility in northwest Houston.
"When Shell decided to exit the waste clean-up business, they essentially turned over their complete, state-of-the-art operations to UT Austin, instead of selling it," said Dr. Gary Pope, director of UT Austin's Center for Petroleum and Geosystems Engineering. "It represented an unusual gift: the technology they provided was fully developed and, therefore, exceptionally comprehensive in its ability to remove many common toxic wastes. Yet it was novel to the marketplace, since it was protected by 19 new patents."
Another important benefit of the arrangement with UT Austin is that proceeds from the licensing agreement will go toward the support of environmental cleanup-related education and research by UT Austin engineering faculty and students, Pope said.
For example, a current UT Austin research project involves testing the use of the process to clean up metallic wastes such as mercury in soil. Dr. Lynn Katz, an environmental engineer in UT Austin's civil engineering department, heads that effort. Pope said the process "hasn't been tried with metals yet. But it's clearly within the realm of feasibility."
Pope was contacted in 1999 through the efforts of the technology's co-inventors, Dr. Harold Vinegar and Dr. George Stegemeier of Shell Technology Ventures. Stegemeier is a UT Austin College of Engineering alumnus who earned his Ph.D. degree in petroleum engineering in 1959.
"These gentlemen already had really close ties with the college's petroleum engineering department and with our research center," said Pope. Pope said the arrangement "wouldn't have happened otherwise."
Shell employed the process commercially for several years with great success before the company left the waste management business. "It's a very simple, very powerful and very versatile technology," said Pope.
ISTD simultaneously applies a vacuum and intense heat to remove sub-surface soil contaminants without resorting to excavation. The method's capacity to destroy and draw out contaminants at the same time represents a big advantage over alternative technologies, such as injection of steam into the soil.
"It directly attacks and completely removes the contamination source, which otherwise could continue to contaminate ground water for hundreds of years," said Dr. Russell T. Johns, an assistant professor of petroleum engineering working on the technology. "Other technologies do not as easily remove the source."
The ISTD cleaning process employs small-bore "heater-vacuum wells" that typically are 10 feet to 20 feet deep. They are set six feet to eight feet apart in hexagonal patterns. An electric heater capable of generating temperatures up to 800 degrees Centigrade is lowered into each well. At the same time, a vacuum is applied.
Heat sufficient to vaporize most volatile liquid wastes also decomposes many organic chemicals into water and carbon dioxide. The vacuum process and a surface seal ensure that all gases generated by the process are captured and treated. Any waste products remaining in the collected gas stream are broken down further by a second "scrubbing" operation: a trip through a thermal oxidizer and carbon bed. What finally emerges is so clean, it is safe to vent to the atmosphere. For shallow soil pollution, the basic heating unit of the heat-plus-vacuum combination takes the form of a series of horizontal heaters stretched across the contaminated soil.
For more information, contact Dr. Gary Pope at (512) 471-3235 or visit www.terratherm.com.
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