Some isolated or poorly ventilated spaces within the U.S. fleet submarines can benefit from local removal of carbon monoxide (CO), which is a very toxic and flammable gas. This SBIR topic seeks to develop an energy-efficient, compact, portable, stable, and stand-alone system to prevent the build-up of CO in such isolated and poorly ventilated spaces. Requirements formulated for such a system are very stringent: the proposed portable system will continually monitor its local space and activate when necessary (i.e., greater than 50 ppm CO) to continuously remove the CO until a local concentration of 5 ppm is attained. The airflow through the CO removal system must be at least 100 cubic feet per minute (cfm). The system must achieve a 95% removal rate over a temperature range of 15C to 25C and relative humidity in the range of 50%-80%. The confined spaces do not have access to cooling water but will have access to electrical power (115 VAC, 100 Watt maximum) for running a fan, operating a CO sensor, and all other system equipment. The system must operate for 10,000 hours without requiring maintenance when 115 VAC power is available. Battery backup must be included to allow the system to remove CO for one hour if 115 VAC electrical power is not available. The final target maximum system weight and volume are 50 pounds (lbs.) and 2 cubic feet, respectively. Continuous oxidation of 50 ppm CO admixture in airflow of at least 100 cfm with a 95% removal rate at room temperature using less than 100 Watt is a challenging task. This task will be resolved using a combination of a catalyst based on gold nano-particles (GNPC) and nano-second pulsed non-thermal plasma (NTP). GNPC by itself loses oxidation efficiency relatively quickly: by 20% in about 10 minutes time on stream (TOS) and by 50% in about 8 hours TOS. It was demonstrated that nano-second pulsed NTP can regenerate GNPC in 5 min. after 70 min. TOS. The novelty of the proposed approach is the use of un-interrupting catalyst regeneration during TOS with the help of nano-second pulsed NTP. R&D efforts during Phase I will allow determining the optimal conditions for CO oxidation by GNPC and for un-interrupting catalyst regeneration. These conditions will then be used during a week-long operational test of the experimental system. The results of this test will be proof of concept for a new method of catalyst performance stabilization, which will be a foundation for the prototype development during Phase II. The Phase I Option will provide additional proof of concept by a two-months-long test of the performance of the developed experimental plasma-catalytic system. Additionally, the Phase I Option will provide time and funding for the initial design of a system prototype, which includes a more powerful pulsed power supply, and for developing a detailed plan of how to construct the prototype in Phase II taking into account special DoN requirements.
Benefit: Technology developed in the framework of the proposed project will be used for the manufacturing of energy-efficient, compact, portable, stable, and stand-alone oxidizing systems that will be used on U.S. fleet submarines. The role of these systems will be local removal of carbon monoxide (CO), which is a very toxic and flammable gas, in some isolated or poorly ventilated spaces within submarines. The technology will be patented; however, it can be used royalty-free within DoN, DoD, and other Federal Agencies. Our company will derive revenue from technological assistance during transitioning the system for Navy use and other military applications. A preliminary study of the potential market for low-temperature CO oxidizers showed that there are several significant areas related to commercial, residential, and military use where these oxidizers could find an application. One possible use would be in automotive repair garages. Another use is air cleaning in warehouses and hangars that use propane-powered forklifts and other internal transport. Many of these vehicles do not have catalytic converters that are the required equipment in modern cars or operate in a start-stop mode when the converters are not efficient. Though the CO concentration in warehouses, hangars, and automotive repair garages can cause health problems for operators and personnel, it is too low for conventional catalytic oxidizers. From this standpoint, the situation is similar to that described in the SBIR topic for submarine air. Another area is air cleaning in commercial kitchens that use natural gas or propane, e.g. in restaurants. Though all kitchens have hoods for removal of food cooking vapors and smoke, the design of these hoods intentionally prevents the interaction of ventilated air with a stove flame. As a result, products of incomplete combustion are not removed effectively by kitchen hoods, and CO concentration in poorly ventilated kitchens can be elevated. Poor ventilation can be caused by large internal and external temperature differences. Though CO concentration is elevated and can cause health problems for kitchen personnel, this concentration is too low for conventional catalytic oxidizers. One more area is air cleaning for commercial maritime operations, recreational boats and ships, including cruise liners. Upon completion of Phase I of the project, we will have a clear direction for the future design and the potential cost of plasma-assisted CO oxidizers, and the patentability of the technology. This knowledge will allow the company to begin the commercialization processes, including marketing potential products and identifying manufacturing partners. The Company believes that the potential market size is on the order of million units, however, it will be studied much more carefully after Phase I. We expect to generate revenue from joint ventures with manufacturing partners, and/or licensing the technology, and development of customized systems.
Keywords: gold nano-particles, gold nano-particles, nanosecond pulsed non-thermal plasma, un-interrupting catalyst regeneration, CO oxidation, Catalyst, Carbon Monoxide