A New Era in Hydrogen Detection - Element One Hydrogen
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A New Era in Hydrogen Detection... Now there’s a better way to positively indicate the presence of hydrogen. Element One’s low-cost visual indica- tors and wireless sensors can: • Improve plant safety, efficiency and productivity • Minimize down time by quickly detecting and showing the location of gas leaks for faster repair Element One has developed and patented a unique family of hydrogen and hazardous gas sensing tech- nologies that form the basis for a wide array of low cost, reliable gas detection systems. The hydrogen systems are based on a simple chemochromic hy- drogen detector that visually indicates the presence– or absence–of hydrogen. Because of their low cost, Element One’s visual indi- cators and wireless sensors can be abundantly de- ployed to detect leaks at the source to complement conventional electronic detection systems. This technology, developed under a cooperative ef- fort with the National Renewable Energy Laboratory, incorporates either thin films or particles of transition metal oxides with a very thin, discontinuous coat- ing of a catalyst to create materials that dramatically change color in the presence of gaseous hydrogen. Gas Off Gas On The indicator rapidly begins to reverse when the hydrogen gas is shut off. A video showing the rapid color change can be seen at www.elem1.com/technology.htm. In addition to our core patent (US 6,895,805), Ele- ment One has additional patents pending for: • Conformable hydrogen indicating wraps (Thin Films) • Hydrogen indicating pigments (Coatings) • RFID hydrogen gas sensors (Wireless) Element One is continuing to improve and test the performance of several prototypical products based on these patents, and will soon have products ready for commercial testing and market introduction. A summary of progress to date for each follows. Thin Films Element One’s thin films may be applied on virtu- ally any substrate, including stretch and shrink films to make indicating wraps and tapes to encapsulate tanks, equipment, fittings and valves monitoring for hydrogen at the most likely leak sites. For selected applications, the film could be deposited in the form of symbols or words that would appear when ex- Indicating paints and specialty coatings, inks, marking pens, indicating tapes, stretch films, shrink wrap, and low cost RFID wireless sensors are just a few of the numerous products made possible by Element One’s technologies.
Transcript of A New Era in Hydrogen Detection - Element One Hydrogen
A New Era inHydrogen Detection...Now there’s a better way to positively indicate the presence of hydrogen.
Element One’s low-cost visual indica-tors and wireless sensors can:
• Improveplantsafety,efficiencyand productivity • Minimizedowntimebyquickly detecting and showing the location ofgasleaksforfasterrepair
Element One has developed and patented a unique family of hydrogen and hazardous gas sensing tech-nologies that form the basis for a wide array of low cost, reliable gas detection systems. The hydrogen systems are based on a simple chemochromic hy-drogen detector that visually indicates the presence–or absence–of hydrogen.
Because of their low cost, Element One’s visual indi-cators and wireless sensors can be abundantly de-ployed to detect leaks at the source to complement conventional electronic detection systems.
This technology, developed under a cooperative ef-fort with the National Renewable Energy Laboratory, incorporates either thin films or particles of transition metal oxides with a very thin, discontinuous coat-ing of a catalyst to create materials that dramatically change color in the presence of gaseous hydrogen.
Gas OffGas On
The indicator rapidly begins to reverse when the hydrogen gas is shut off. A video showing the rapid color change can be seen at www.elem1.com/technology.htm.
In addition to our core patent (US 6,895,805), Ele-ment One has additional patents pending for:• Conformable hydrogen indicating wraps (Thin Films)• Hydrogen indicating pigments (Coatings)• RFID hydrogen gas sensors (Wireless)
Element One is continuing to improve and test the performance of several prototypical products based on these patents, and will soon have products ready for commercial testing and market introduction. A summary of progress to date for each follows.
Thin Films
Element One’s thin films may be applied on virtu-ally any substrate, including stretch and shrink films to make indicating wraps and tapes to encapsulate tanks, equipment, fittings and valves monitoring for hydrogen at the most likely leak sites. For selected applications, the film could be deposited in the form of symbols or words that would appear when ex-
Indicating paints and specialty coatings, inks, marking pens, indicating tapes, stretch films, shrink wrap, and low cost RFID wireless sensors are just a few of the numerous products made possible by Element One’s technologies.
posed to hydrogen, making leaks or flammable mix-tures readily recognized by the untrained eye. Applications include coatings for protective gear, equipment, piping and valves, storage tanks, ve-hicles, stationary appliances, connectors, refueling stations or in closed spaces such as garages.
Coatings
Element One’s hydrogen indicating pigments are the only available coatings for the detection of hydrogen that change color, either reversibly or non reversibly as desired, to give both current and historical infor-mation about leaked hydrogen.
Particles of transition metal oxides can be used as pigments in indicating paints and printing inks. Coat-ings may be applied with a brush, spray can, paint or marking pen, or used to coat decals or tape that may be affixed wherever a leak might occur.
In a round of environmental applications testing at the NASA/Kennedy Space Center corrosion test fa-cility in Florida, our thin film samples performed ex-tremely well.
Visual Indicators with Adjustable Recovery Times
Element One is developing films and pigments that could be applied as dots of chemochromic material, each having different properties that would change back to normal coloration at varying rates. One dot could react rapidly while others could revert at varying rates to provide historical information over a period of minutes or hours. Such decals could be placed on the inside of fuel doors on vehicles, worn as badges, or placed anywhere an indication of the presence of leaked hydrogen is needed.
Figures 1 through 3 illustrate the adjustable recov-ery time that can be built into coatings. The pair of samples in the upper right are the fastest. The one horizontal sample at the bottom of each figure with the dark spot is essentially irreversible. The exposed spot will remain dark for weeks. This cus-tomizable response is also applicable to thin films. Figure 4 shows the rate of change of the pigment in the paint.
Fig. 1 Immediately after coloring the reversible paint samples. The bottom irreversible sample was exposed in the center spot two weeks earlier.
Fig. 2 After 1.8 hours.
Fig. 3 After 16 hours.
Fig 4. Rate of Change
A Recognized Need “Although safety-by-design and passive mitiga-tion systems are preferred, it will still be nec-essary to develop technologies to detect hy-drogen releases or other system failures. For example, coatings that change color uponexposure to hydrogen can provide immedi-atevisualevidenceofaleak.”
U.S.DOEMulti-YearPlan2003-2010
Wireless
In addition to coating and thin films, Element One has developed another family of products that use Radio Frequency Identification Devices (RFID), and completed initial development of an RFID-based hy-drogen sensor that can be deployed abundantly in hydrogen plants and distribution facilities. The sen-sor prototypes could be integrated into a new genera-tion of RFID “Smart Tags” that will store and transmit information about hydrogen leaks.
Integration of these sensors into a network will pro-vide a low cost, effective system for monitoring for leaks. In such a network of perhaps hundreds of sensors, each RFID tag may be interrogated as of-ten as once every second.
With further development, these RFID tags may have the capability to also give information about the magnitude as well as the existence of a leak. This information will be invaluable to plant safety and maintenance personnel in assessing whether a pro-cess must be shut down immediately or to continue monitoring and schedule a repair at the next oppor-tunity.
Element One’s Technology
Our visual hydrogen gas indicators use thin films or particles of a transition metal oxide. A very thin coating of a catalyst is applied to the transition metal oxide to catalyze its reaction with hydrogen.
Thin FilmsA typical thin film indicator consists of a transparent polymer substrate, a 500 nm thick layer of tung-sten oxide, a 3 nm layer of palladium catalyst, and a 100 nm thick protective coating of poly-tetrafluo-roethylene (PTFE). The tungsten oxide layer is nano-porous. The semitransparent catalyst layer is discontinuous, consisting of nano-scale islands on top of the tungsten oxide. The very thin PTFE partially protects the catalyst from poisoning by at-mospheric pollutants. It also tends to stabilize the thin film stack against abrasion by providing a low friction surface. All of the layers are deposited by thermal vaporization in vacuum.
Vacuum deposited multi-layer
thin film
PTFE 100 nmPalladium 3 nmTungsten oxide 500 nmSubstrate polymer sheet
Chemically synthesized
particles
Tungsten oxide powder
Platinized chemically
ParticlesParticles of transition metal oxides are coated with a partial layer of catalyst by conventional chemical techniques. These particles can be used as pig-ments in indicating paints and printing inks.
Typical Structure of Chemochromic Indicator Material
The resistance of the Element One RFID Sensor Pro-totype changes from above 60 mega-ohms to less than 60 kilo-ohms when hydrogen is detected.
Wireless Sensor
power with its attendant hazard of an electrical fault causing ignition of an explosive mixture, and none meets all of the criteria for all applications.
About Element One, Inc.
Element One, Inc. is based in Boulder, Colorado. The company was formed to develop and market new low-cost hydrogen indicators based on new patented and proprietary technologies that use chemochromic materials and newly developed fab-rication techniques as the basis for a wide array of low-cost, wide area hazardous gas indicators. Sen-sors for hydrogen sulfide, ammonia, and chlorine gas are also under development.
Element One is currently seeking additional devel-opment partners to participate in the testing and product development of new products for safely and reliably monitoring systems for the detection of hy-drogen leaks and hazardous mixtures of hydrogen in air. If you have a requirement and would like to discuss specific products and applications, contact:
William Hoagland(720) 222-3214
Copies of technical papers and presentations are available
on our web site:
www.elem1.com
Element One, Inc. 7253 Siena Way
Boulder, CO 80301
720.222.3214
Better Than Typical DetectionSystems
Detection systems must ultimately trigger one or more of the human senses (sight, smell, hearing, taste, and touch). This is why odorants are added to natural gas pipelines. A typical hydrogen detection system is comprised of a sensor, transducer, and another device such as a bell, buzzer or light to be detected by one or more human senses.
Existing hydrogen gas sensors may be too large, too immobile, too complex, or too expensive for widespread use. Mass spectrometers and chro-matographs, for example, are extremely sensitive, but are also large, immobile, expensive, require skilled operators, and may have long response times. Portable detection devices are too expen-sive for the wide area coverage that can be eco-nomically obtained using the new visual indicator.While many of these methods perform well un-der certain conditions, most require electrical
Market Advantages/CustomerBenefits of
Visual Hydrogen Indicators
√ Visible - convenient indication from a distance
√ Inherentlysafe-noelectronics√ Reversible or non-reversible versions√ Simple - No instrumentation needed√ Convenient,VeryLowcost√ Flexible - Applicable in various forms • Paint • Decals • Conformablewrapsandtapes√ Selective - detects hydrogen only√ Sensitivetohydrogen-1/100oflower
flammability limit.√ Positiveindicationofbothpresenceor
absence of H2
√ SuitableforLow-costWirelessSensors
