August 2, 2005
Roanoke, W.Va. – While our nation’s leaders may envision non-polluting hydrogen as the fuel of the future, researchers like West Virginia University‘s Dady Dadyburjor and Edwin Kugler will make that vision real.
Chemical engineering professors Dadyburjor and Kugler are directing hydrogen studies through the Consortium for Fossil Fuel Science, a five-university group that includes WVU, the University of Kentucky, the University of Utah, Auburn University, and the University of Pittsburgh. WVU’s efforts are coordinated through the WVU National Research Center for Coal and Energy.
While hydrogen is perhaps the most abundant element in the universe, hydrogen does not exist in its pure state on earth. It must be derived from some source. The CFFS is seeking routes for hydrogen from abundant domestic resources such as coal and coal-bed natural gas.
Today, most hydrogen is derived from methane, the prime component in natural gas, through a process involving steam. Dadyburjor, Kugler and their team of students and post-doctoral researchers have been focusing their efforts on energy from coal, including deriving hydrogen using methane and carbon dioxide.
The process, known as dry reforming of methane or DRM, uses lower pressure than steam reforming, potentially making it less expensive if the right catalyst can be designed.
“Catalysts are materials that increase the rate of chemical reactions without themselves being reacted,” Dadyburjor explained. “Catalysts are critical for all chemical processes, from the manufacture of plastics to the conversion of harmful air pollutants in the catalytic converters in our automobiles,” he said.
Today, nickel catalysts are the commercial choice. While they are inexpensive, nickel catalysts are prone to coking which causes them to lose their reactivity quickly. Nobel metal catalysts such as platinum stay reactive but are very expensive. Metal carbide catalysts are moderately resistant to coking and are moderately active. Dadyburjor and Kugler hypothesized that adding a second metal would improve the performance of carbide catalysts.
They were right—the researchers developed a tungsten-cobalt carbide catalyst that outperforms current commercial nickel-based catalysts. Their catalyst is long-lasting and can be recovered and reused.
“We have had the tungsten-cobalt carbide catalysts operate for about 200 hours in the reactor,” said Dadyburjor. “This is a tremendous amount of time for an academic lab. In fact, the only reason that we had to turn off the process was that the student needed to graduate,” he said.
The team’s results were presented at the CFFS annual technical meeting at Stonewall Resort in Roanoke, W.Va., August 1-3. Gerald Huffman, CFFS director, called Dadyburjor and Kugler’s results, “Impressive.”
The researchers suggest that a DRM facility is particularly relevant for stranded natural gas, that gas which does not have access to a transmission line or where a transmission line is already at capacity.
“For example,” said Dadyburjor, “a DRM facility could be located above an unmineable coal seam. Some amount of natural gas is present in all coal,” he said.
The catalytic conversion of methane with carbon dioxide in a DRM facility would produce not only hydrogen, but also carbon monoxide. The carbon monoxide could be reacted with water to produce more carbon dioxide and more hydrogen.
Some of the newly produced carbon dioxide could be fed back into the DRM process. The remaining carbon dioxide could be pumped into the coal seam to enhance the production of more coal-bed methane, while capturing and storing the carbon dioxide in the geologic formation, Dadyburjor suggested.
In fact, carbon dioxide has long been used by the oil and gas industry to increase the amount of oil and gas extracted from wells.
“Another possibility is to convert some of the hydrogen and carbon monoxide, also known as syngas, into liquid fuels to replace petroleum imports,” added Kugler. “Until there is a significant market for hydrogen for transportation, it makes sense to convert the hydrogen into liquid fuels that can be used today,” he said, adding that such liquid fuels burn more cleanly than petroleum-based fuels.
Kugler added a third option, using the syngas in a solid oxide fuel cells to produce electricity. “Imagine, a coal company with reserves far from the power grid,” said Kugler. “The company could erect a DRM facility, produce hydrogen and carbon monoxide, and then feed the fuels into a solid oxide fuel cell to make electricity for the mine, all without having to connect to the grid.”
Such imaginings backed by research offer hope of bringing the hydrogen economy ever nearer.