NETL's Recently Patented Technologies

NETL Patent Addresses Catalyst Deactivation, Diesel Reformation

When NETL researchers patented a unique hexaaluminate catalyst, they advanced the technology a long way toward solving problems associated with catalyst deactivation--a problem that had long inhibited processes such as diesel fuel reforming.

Hexaaluminate unit cell illustration.

Until the NETL patent, researchers wrestled with the problem that commercially available catalysts would deactivate in the presence of sulfur and aromatic compounds. As a result, the presence of those compounds in diesel fuel represented a major problem in reforming the fuel. If researchers were to successfully convert diesel fuel into synthesis gas--a process known as reforming that requires a catalyst--then a solution for the deactivation problem had to be found.

The NETL researchers developed a method to reform hydrocarbon fuels using hexaaluminate catalysts. In general, the method successfully disrupts the formation of carbon that leads to the deactivation of the catalysts, a key element in the reforming of hydrocarbon fuels, and minimizes deactivation under the most severe reforming conditions.

The NETL patent, titled "Methods of Reforming Hydrocarbon Fuels Using Hexaaluminate Catalysts" by Todd Gardner, Dushyant Shekhawat, and David Berry, works by using the unique unit cell structure of the hexaaluminate oxide compound as a molecular scaffold to atomically disperse and support catalytically active metals. By doing so, the active metals are maintained in a state of low coordination to disrupt the carbon formation. A series of articles (Gardner et al., J. Phy. Chem. C 114, 2010, 7888-7894 and Catal. Today 157, 2010, 166-169) describes the unique structural characteristics and catalytic properties of the materials.

The technology could be applied, for example, to the trucking industry where hydrogen needed for fuel in solid oxide fuel cells can be produced by converting the hydrocarbons present in long-haul truck diesel fuel into synthesis gas. Nationwide, 2.2 million long-haul trucks annually produce an estimated 11 million tons of carbon dioxide, 200,000 tons of nitric oxide, and 5,000 tons of particulate matter. While idling, the trucks waste more than 1 billion gallons of diesel fuel. By incorporating solid oxide fuel cells, these trucks could obtain power from a cleaner, more efficient power source.

Research is currently active on the technology, and it is available for licensing and/or further collaborative research from NETL. The technology could potentially compete with conventional methane reforming catalyst technology, and it is useful for dry reforming, partial oxidation, and steam reforming applications.

Integrated Pollutant Removal Process Captures CO₂

NETL's Integrated Pollutant Removal™ (IPR) process captures “smoke” from fossil-fueled power plants using oxycombustion, a process that burns fuel in pure oxygen rather than air, which contains only about 20 pct oxygen. Collaborative testing and development mating Jupiter Oxygen's high-temperature oxycombustion approach to NETL's IPR process provides data that can be used to bolster designs of near-zero emissions power-plants. A joint patent for such a power plant was awarded to this team on October 18, 2011 (8,038,773).

IPR test rig with oxyfuel boiler at Jupiter Oxygen's Hammond Burner Test Facility (JHBTF).

To use hydrocarbon fuel (coal, oil, natural gas) without adding to our atmosphere's load of carbon dioxide (CO₂), the CO₂ produced from combustion needs to be stored rather than released to the air. Deep within the earth's crust is the main target-space for this storage. In order to inject CO₂ to sufficient depth, we need to pressurize it to approximately 2000 psi. Capturing and compressing CO₂ is work that power plants have not had to perform to date. To be practical, this work must be done with as little extra energy as possible. The IPR process, capturing exhaust from oxy-combustion, accomplishes this by sharing the heat it generates with the power-plant and by purifying the CO₂ it captures with the water which condenses in IPR from the processed exhaust.

Currently, fuel is burned in air, which is about 79% nitrogen, 20% oxygen and 1% other gases. Oxy-combustion brings only the oxygen-portion to the fuel. Therefore, oxycombustion exhaust is undiluted by air-nitrogen. Because of this, there is very little untargeted material for IPR to capture. Made up of about two thirds CO₂ and about one third water, with smaller amounts of acid gases (SO_x, NO_x, Cl_x) and heavy metals like mercury from the coal, this exhaust enters IPR hot and releases its heat to water-spray in a scrubbing tower. The remaining gas goes through a compression/cooling process repeatedly, releasing heat and dropping out water (containing pollutants) at each stage. The IPR cooling processes release heat to the power-plant. Captured water is cleaned for reuse in the plant or release back to the environment.

Schematic of an oxycombustion/IPR power plant.

NETL and Jupiter Oxygen are working jointly to develop both technologies in tests being performed at the Jupiter Oxygen Hammond Burner Test Facility (JHBTF) as well as through models of the test-installations and system models of power-plants employing oxycombustion/IPR for CO₂ capture. NETL researchers will use the results of this modeling to develop the engineering knowledge base to help ease the implementation of CO₂ capture if and when it comes into practice.

Through the joint patent (Integrated Capture of Fossil Fuel Gas Pollutants Including CO₂ with Energy Recovery) describing the use of IPR technology with the use of Jupiter's high-temperature oxycombustion approach, Jupiter Oxygen and NETL are working to transfer this near-zero-emission strategy for fossil-fuel power production to the larger public sector.