NASA Tech Briefs: What was the LTOC method originally developed for? Dr. Jeff Jordan: The NASA LTOC was originally developed to meet the need for space-based carbon dioxide (CO 2 ) lasers that were being applied to atmospheric science applications such as measuring ozone. In a carbon dioxide laser, the CO 2 is broken down during the lasing process to carbon monoxide. So, for ground- based CO 2 lasers this is a trivial issue because you can just replenish the CO 2 with a new gas cylinder. But, at $10,000 per kilogram to ship mass into low-Earth orbit, it becomes non-trivial and cost prohibitive. So, the advanced chemistry group was called upon to develop a catalyst that would oxidize carbon monoxide to carbon dioxide under the cold vacuum conditions of space. Current technologies at the time would only operate under elevated temperatures, so this was a challenge. It turns out that by the time they developed this LTOC, the need for carbon dioxide lasers in space was supplanted by solid-state laser technology. So, our team endeavored to adapt the LTOC for environmental remediation applications by exploiting its relatively unique low-temperature operation capability. One exciting activity focused on the development of LTOC-based catalytic converter technologies for internal-combustion applications with industry partner Airflow Catalyst Systems, Inc. of Rochester, NY. Most recently, this low-temperature capability has been exploited to address formaldehyde remediation in industrial smokestack emissions. NTB: What are current pollution remediation technologies? What makes the LTOC method a better alternative? Dr. Jordan: Many industrial processing schemes involve the heating of raw materials to enable mold castings (e.g., plastics), thin film fabrication (e.g., microelectronics), and extrusion (e.g., filter materials) as the first step in product manufacturing, to name just a few. The heating of polymeric and other man-made materials can liberate volatile organic compounds (VOCs), many of which are harmful to the environment. Of particular concern is the emission of formaldehyde, which has been the subject of investigation and regulation by the U.S. Environmental Protection Agency. Existing technologies for the remediation of formaldehyde from industrial smoke stack effluent streams include water misting and total combustion furnace technologies. In the mist-and-treat method, the emission stream is subjected to a water mist, which serves to condense formaldehyde and other VOCs. The formaldehyde and VOCs are captured in the collected water, which is then recovered and shipped to chemical processing facilities where the formaldehyde is removed from the water and destroyed by conventional means. This is a time-consuming and costly process that exhibits insufficient capacity to remove formaldehyde at levels encountered in the heating of many classes of industrial-use resin materials. Total combustion furnaces do not suffer the limitations of water-misting technologies, however, they are very costly to procure, integrate, and maintain for the purpose of reducing VOC emissions, specifically formaldehyde emissions in industrial processing facilities. When compared against the millions of dollars a year per facility that these technologies require, the LTOC application becomes ever increasingly favorable from both a cost and ease of integration perspective. NTB: How exactly is the NASA LTOC being applied to reduce smokestack emissions? Dr. Jordan: The system that our team designed consists of an intake pipe that is the same diameter of the pipe of the native smoke stack system. The emission flow is split into multiple tubes that are each lined with catalyst-coated honeycomb-shaped bricks. As the gases pass over the catalyst surface, formaldehyde and other VOCs are converted to carbon dioxide (CO 2 ) and water prior to emission through the smoke stack. The system architecture facilitates the integration into existing facilities and maintains the flexibility to be optimized based on mass flow, plumbing architecture, diameter of the actual pipes used, and pollutant concentration considerations. This multiple pipe design also lends itself to continuous operation, because individual channels can be closed and isolated from the flow to accommodate routine maintenance. NTB: Has the LTOC technology been proven successful? Dr. Jordan: At this time we are awaiting a demonstration test and we are working on this in collaboration with our industrial partner and technology licensee, Automated Control Technologies, Inc. (ACT) of Fairmont, WV. They have been working in collaboration with NASA and other agencies, as well as the state of West Virginia and a local fiberglass processing plant to enable this demonstration test, which is scheduled to occur sometime within the next couple of months. NTB: What role has ACT played in the development of this technology? Dr. Jordan: Their main focus in this industry is to provide automation and control technologies for industrial manufacturing facilities, so they identified the need in response to corporations' issues with the new EPA requirements. ACT approached NASA's Technology Commercialization Program Office (TCPO), and under TCPO support, our team tested LTOC formulations for this application and worked with ACT personnel on the conceptual design of the system. ACT then designed and fabricated a single-channel prototype system. The catalyst-coated bricks were fabricated in NASA laboratories and sent to ACT for installation into their catalytic insert system at a fiberglass processing plant in West Virginia. NTB: Can you explain in further detail the LTOC tests to be conducted? Dr. Jordan: The test will involve formaldehyde detectors both upstream and downstream of our catalytic prototype insert to measure the efficiency of the formaldehyde destruction over a range of varying conditions to assess system performance. The multi-channel design provides a mechanism to vary the mass flow, temperature and the ratio of emission gas to external air to accommodate optimization for individual facilities and different process streams. NTB: The NASA LTOC technology was never implemented for its original purpose, and yet it's still being applied to address a wide range of air pollution problems. Did you ever imagine that you'd be working with private companies on such diverse applications of the LTOC? Dr. Jordan: It's been an exciting experience and very rewarding to adapt NASA technology for integration into efficient and cost-effective systems to reduce industrial emission pollutants. It has been a great opportunity to be able to contribute technologies that will improve air quality and human quality of life on a global scale—a mission that is central to the NASA agency. I feel proud as an American taxpayer to contribute to such a worthy cause. NTB: Is NASA still accepting license inquiries for LTOC applications? Dr. Jordan: The LTOC is already licensed for several fields of use, but NASA is still accepting applications for additional areas. You can contact Dr. Frank Farmer (757-864-2490) at NASA Langley for information regarding license opportunities.
|
||||||||||
