Release Date: June 13, 2006
|DOE Projects Provide Stepping Stone to America's Hydrogen Economy
New Twist on Old Technology Stresses Feedstock Flexibility, Plant Mobility, Lower Emissions
WASHINGTON, DC - Department of Energy (DOE)-funded research is tweaking an old technology to develop new supplies of ultra-clean liquid transportation fuels from both coal and natural gas—and in the process provide a new source of non-polluting hydrogen energy.
Two projects managed by the Office of Fossil Energy's National Energy Technology Laboratory (NETL) use a proprietary technology developed by Syntroleum Corp. of Tulsa, OK, to convert the Nation's abundant raw fossil fuels into either hydrogen or high hydrogen-content liquids, such as ultra-clean diesel and other environmentally-friendly liquid fuels.
Syntroleum's natural gas-based gas-to-liquids (GTL) demonstration plant at Port of Catoosa, OK, has produced more than 330,000 gallons of ultra-clean diesel, jet, and naphtha fuels for various government programs since its start-up in 2003.
On March 30, 2006, DOE awarded funding of about $4.3 million for a $5.4 million project that would further develop Syntroleum technology to produce either hydrogen or high hydrogen-content, ultra-clean liquid fuels from coal—dubbed coal-to-liquids (CTL). The funding was part of a broader award of $62.4 million for 32 U.S. clean coal research projects. The Syntroleum CTL research is especially promising for America's energy security because of the Nation's vast coal reserves—the world's largest. If only 5% of U.S. coal reserves were converted to liquid fuels, it would equate to doubling America's proven oil reserves.
The lead partner in both projects with Syntroleum is Integrated Concepts & Research Corporation (ICRC), a subsidiary of Koniag Inc., an Alaskan Native Corporation with offices in Anchorage and Kodiak, AK. Marathon Oil Corporation also is a partner in the Catoosa demonstration plant. ICRC teamed with the University of Kentucky and the University of Alaska-Fairbanks in the coal-based project.
Syntroleum's GTL and CTL processes are based on a technology that has been around more than 70 years. German scientists Franz Fischer and Hans Tropsch developed a process for converting coal into liquid fuels in the early 1920s. The Fischer-Tropsch (FT) process is still used for CTL in South Africa, and a GTL demonstration plant started up in that country in 2004.
GTL technologies have received a great deal of petroleum industry attention in recent years. But what's envisioned are usually megaprojects costing upwards of several billion dollars and tied to gas fields holding 50-500 trillion cubic feet (Tcf) in reserves. Most of these megaprojects are planned for the Middle East, home to the lion's share of the world's oil and gas reserves.
That's where the Catoosa GTL plant comes in. The DOE Catoosa project called for the design and construction of a modular, "small-footprint" plant for converting natural gas to an ultra-clean diesel motor fuel, scaled to a gas reserves source of only 1-3 Tcf. The demonstration plant produces a sizable quantity of a synthetic crude oil feedstock from natural gas that is then converted to finished products via FT and hydroprocessing steps. The FT fuels then are tested in a variety of engines and vehicles to determine their compatibility with today's fuel injection systems and their ability to reduce tailpipe emissions.
The Catoosa GTL plant, which went on stream in November 2003, produces about 70 barrels per day of ultra-clean diesel. The plant design achieves a 25% reduction in construction and operating costs because the Syntroleum process relies on air rather than oxygen—thus avoiding the cost and safety issues with an onsite oxygen plant, according to a NETL Project Manager.
"This process differs from those [developed by the major oil companies] in two areas: it uses air, rather than oxygen to form syngas, and it's designed to be mobile," the Project Manager added. "The advantage of this system is that it can be moved to the resource, and its size is designed to take advantage of smaller resources that the majors cannot develop cost-effectively."
The small, modular nature and multiple-fuel capability of the Catoosa GTL plant design gives it a portability and logistical flexibility that already has attracted the attention of the U.S. military for possible battlefield applications.
The Catoosa plant's output has undergone real-world testing. The ultra-clean diesels fueled Metrobuses in Washington, DC, and bus fleets in Alaska's Denali National Park. Early results showed significantly reduced emissions and improved vehicle performance. The GTL diesel burns with much less of the soot commonly seen in diesel exhaust and surpasses not only current, but also pending Federal and State air quality standards for ultra-low levels of sulfur in fuels.
The Denali National Park summer testing was so successful that park officials asked to continue use of the fuel into the subsequent winter months.
Another environmental benefit of GTL is its potential to end natural gas venting or flaring—the controlled release or burning of gas that is sometimes economically necessary to produce the oil with which it is associated. More than 100 billion cubic meters of natural gas are lost annually to venting or flaring at sites around the world—enough to meet the natural gas needs of France and Germany.
GTL also holds the promise of monetizing an enormous natural gas resource that is "stranded" for lack of a market. The world's stranded gas reserves total about 2,500 Tcf. If this resource could find a market, it would exceed in energy-equivalent terms, Saudi Arabia's proved oil reserves.
Yet another benefit is the co-production of naphtha, an ideal fuel for fuel cells, a power source increasingly gaining attention for use in distributed power generation and in low-emission, high-mileage vehicles.
In the DOE-funded clean coal-to-liquids project, ICRC and Syntroleum will assess a cobalt-based FT catalyst for converting coal-derived synthesis gas to high hydrogen-content liquids, with an eye to producing research quantities of these liquids. Researchers will evaluate commercially available coal gasification and synthesis gas cleanup technologies. They then will seek to integrate these technologies with Syntroleum's cobalt-catalyst-based FT process as a precursor to an eventual commercial-scale CTL plant. In addition, engineering and economic analysis will be undertaken to assess the commercial feasibility of such a plant in a coal-producing state.
The 24-month CTL project will field-test research quantities of the liquids produced from coal-derived synthesis gas using the cobalt-catalyst FT process. The research volumes of coal-derived liquids produced during the project will be further processed into a range of products for end-use studies. These studies will include evaluation of these high hydrogen-content liquid fuels, such as:
Such field tests are intended to enhance public awareness and market acceptance of the environmental and energy security benefits of CTL transportation fuels and the potential for using these fuels as an easily handled source of hydrogen in reformer/fuel cell systems.
|Contact: David Anna, DOE/NETL, 412-386-4646|