In the Lab
Rocket Science Gives Electricity Generation a Boost
Using rocket technologies, Clean Energy Solutions Inc. has developed a technology that could generate low-cost, pollution-free electricity from fossil fuels.
The Sacramento, Calif., firm composed largely of retired rocket scientists, approached Lawrence Livermore National Laboratory (LLNL) about building a research facility, since utility companies usually require a new technology to operate for five or six years before purchasing it.
"Utilities are known for wanting to buy the second or third plant, never the first," said Ray Smith, LLNL's Applied Energy Technology Program leader. "We think the government should reduce the scientific and economic risk by building the first plant."
Lab officials plan to submit a proposal to the U.S. Department of Energy (DOE) this year to build a 10 megawatt, $70 million facility at the Laboratory based on Clean Energy's technology.
Possible fuel sources for the Clean Energy system include natural gas, synthetic gas from coal, petroleum and biomass.
The firm's gas generator burns the fuel, as well as oxygen and water at high temperatures, around 2,600 degrees Fahrenheit, and produces a gas of steam and carbon dioxide. Like a rocket engine, the generator burns pure oxygen to produce steam and avoids the production of nitrogen oxides.
The steam powers turbines that drive an electric generator, producing energy without pollutants. A condenser cools the steam into water and separates it from the carbon dioxide.
Much of the water returns to the generator, and along with pure oxygen and the fuel source, provides more steam to drive the electric generator.
"Clean Energy's technology represents a whole new approach to producing steam and electricity cleanly," Smith said. "It replaces six-story high steam boilers with a generator that is seven to eight feet long and one foot in diameter."
Developers plan to send carbon dioxide from the proposed Zero Emission Steam Technology (ZEST) facility to an oil field just east of the Laboratory through a pipeline, where it would be used to boost oil production.
"A key part of the research we want to do is for the sequestration of carbon dioxide - how much of the gas stays in the oil field and whether it can also be sequestered in deep saline aquifers," said Smith.
Scientists estimate that the resultant carbon dioxide could be deposited underground at less than $20 per ton of carbon, compared to $100-plus per ton required for removing the gas from exhausts of conventional electricity plants.
Tests run by Clean Energy so far have been successful, according to company president Steve Doyle.
"We met all of our expectations. We learned more about gas kinetics and gas composition than we expected," Doyle said. "We were trying to prove that we could cool down the gas, from 2,600 degrees Fahrenheit to 1,000 degrees, and keep the flow almost completely steam and carbon dioxide without forming any pollutants, and we did so."
Clean Energy Systems has received a $75,000 grant from the California Energy Commission to build a scale model of its generator at the University of California and is currently negotiating a contract with the DOE.
For more information, visit LLNL at www.llnl.gov or Clean Energy Systems Inc. at www.cleanenergysystems.com.
Waste Not
A Battelle technology brought to the Northwest by researchers at the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) is transforming a waste lagoon into a waste treatment facility at a Washington state dairy.
The George DeRuyter Dairy in Outlook, Wash., has been outfitted since January 2001 with InStreem™, a technology that enhances naturally occurring biological activity to clean waste lagoons. Henry Pate of Battelle's Florida Marine Research Laboratory developed InStreem.
Lagoons traditionally have been used to store manure and liquid effluent from dairy herds. Wastes stored over the winter months are pumped onto fields in the spring where crops utilize the manure's nutrients. However, more nutrients, such as nitrogen and phosphorous, may be applied to crops than can be used effectively.
"InStreem is designed to use a dairy's existing infrastructure to convert lagoons from waste storage facilities to facilities that solve waste problems," said John Jaksch, PNNL program manager for the project in the Pacific Northwest. "In doing so, this technology addresses one of the dairy industry's most pressing issues."
Unlike conventional treatment methods, InStreem converts existing lagoons into extended aeration systems, establishing conditions favorable for both aerobic and anaerobic degradation of wastes. The aerobic process is designed to remove excess nitrogen and the anaerobic process is designed to remove other nutrient constituents, such as phosphorous. InStreem maintains an oxygen deficit condition in the lagoon and does not over aerate, while still allowing nutrient reduction to take place and bacteria to work on reducing the manure sediments. One InStreem unit treats a lagoon one to one and one-half acres in size.
To date, the demonstration is exceeding Jaksch's expectations. "In three months, the depth of solids dropped from six feet to six inches, and that was during the coldest part of the year," Jaksch said.
Additionally, InStreem has been successful tackling a problem common to all dairies -- odor. "Within two weeks of operation we noticed a huge reduction in odor," said George DeRuyter, owner of the diary. "Odors on the lagoon banks now are barely detectable."
The DeRuyter dairy, located on the dry, eastern side of Washington, is a large operation with approximately 2,600 head of cattle. DeRuyter utilizes a flush system in which the feed/loafing areas are flushed hourly with water. Manure is carried by water through a solids separator. The solids are turned into compost and the wastewater, laden with suspended manure solids, is returned to the lagoon, where it is recycled back into the flush system after processing.
The DeRuyter demonstration, which is on a lagoon approximately one and one-third acre in size, will run for one year. Soil Search of Finley, Wash., is assessing the demonstration by monitoring the site for nitrate, nitrite, ammonia, total phosphates, sulfates, chloride, biological oxygen demand, chemical oxygen demand, total and dissolved solids and fecal coliform bacteria. Soil Search provides nutrient management and precision farming services for the dairy industry in the Pacific Northwest.
"We chose DeRuyter's because it enabled us to demonstrate the technology under difficult conditions," said Jaksch. "Also, through an existing relationship with DeRuyter, Soil Search has more than four years of sampling data on the lagoon, providing invaluable background data for measuring InStreem's performance."
For more information, call 1.888.375.PNNL or e-mail inquiry@pnl.gov.
This article originally appeared in the December 2001 issue of Environmental Protection, Vol. 12, No. 12, p. 10.
This article originally appeared in the 12/01/2001 issue of Environmental Protection.