USC's Jet Propulsion Lab Announces Patent For Methanol Fuel Cell (1997)
Cool, Safe, Compact, Light, Efficient, Non-Polluting New JPL-USC Methanol Fuel Cell Shows Promise For Zero-Emission Vehicles
PASADENA, CA - February 25, 1997: A revolutionary design for a cool-process, zero-emission methanol fuel cell just patented by Caltech's Jet Propulsion Laboratory and the University of Southern California is already under fast-track development for a wide range of uses.
In one major project, developers believe they can create a unit about the size of a thick paperback book that can run continuously for weeks at a time, producing 50 watts of power, consuming about a pint of methanol fuel per day, and emitting only water and carbon dioxide.
The technology, whose development was funded by the U.S. Defense Advanced Research Projects Agency (DARPA) and private sources, is easily scaleable into larger units capable of powering portable non-polluting electronic equipment or, eventually, zero-emission motor scooters or cars. The U.S. military is interested in the technology for its potential of providing portable power to soldiers in the field.
A private sector corporation, DTI Energy, Inc., headquartered in Los Angeles, has licensed the technology and intends to develop and sublicense various prototypes and applications. It has initially designed units of up to 5 kilowatt output, powerful enough to run a light-duty vehicle.
"This fuel cell may well become the power source of choice for energy- efficient, non-polluting electric vehicles," said JPL fuel cell team manager Gerald Halpert.
"This invention also has vast potential to improve the environment by providing clean energy in portable form, " noted Nobel prize-winning chemist George Olah of USC, one of the co-inventors.
Like all fuel cells, the JPL/USC device, called a "Direct Methanol, Liquid Feed Fuel Cell," converts the chemical energy of its fuel directly into electrical current without burning the fuel. It has many remarkable advantages:
• It uses the common and widely used substance, methanol (a liquid
also known as methyl alcohol) as the base fuel mixed with
water. Methanol is inexpensive (currently, approximately 40 cents per
gallon), easily manufactured from coal or natural gas, and safe to
store -- existing gas stations could easily sell it.
• It runs relatively cool -- below the boiling point of water -- and is compact. Existing fuel cells typically operate at high temperatures, some at temperatures hot enough to melt many metals, thus requiring bulky thermal insulation and structural reinforcement to mitigate safety hazards.
• It creates no toxic byproducts whatsoever. The methanol fuel is completely converted to carbon dioxide (CO2) and water.
• It is simple and relatively inexpensive to manufacture, consisting of little more than a membrane coated with platinum or other noble metals. The cell itself has no moving parts. Its precious metals are used in small amounts and can be completely recovered and recycled at the end of the device's life.
• It is efficient. In its existing configuration, it converts more than 34 percent of the theoretical energy content of the fuel into usable power. This is twice the efficiency of existing gasoline engines. Developers believe that improvements now on the drawing board will push the efficiency to more than 45 percent of theoretical energy content.
A U.S. patent for an "aqueous liquid-feed organic fuel cell using solid polymer electrolytic membrane" was issued early this month with Caltech, JPL's parent organization, and USC as joint patent holders.
"In addition to not polluting the environment," noted JPL's Dr. Subbarao Surampudi, who supervises JPL's Electrochemical Technologies Group, "we believe that cells of this design can replace batteries in many applications and provide reliable emergency power in disasters." Battery manufacturing involves toxic materials, so the disposal of used batteries has become a major problem, scientists note.
Prototype cells have been assembled and tested at JPL. According to Dr. Halpert, these models have run for more than 200 hours continuously at JPL and for more than 3000 hours intermittently -- equivalent to approximately 150,000 miles -- at partner Giner Inc.'s labs without loss of performance. Current design goals envision units that can operate continuously for 1000 or more hours, and, eventually, units that can produce the 40 kilowatts or more required to power a full-sized car. "The system's simplicity as a clean- energy alternative to the use of fossil fuel-powered combustion engines will generate widespread appeal in the automotive industry," predicts Halpert.
The fuel cell's design is quite simple. A membrane divides the cell in half, with methanol fuel in water on one side and gas, either oxygen or air, on the other. The membrane is coated on both sides with a special, electrochemically active catalytic coating developed by JPL. The liquid side is the anode. Methanol -- a molecule consisting a single carbon atom linked to three hydrogen atoms and one oxygen-hydrogen (hydroxyl) group -- spontaneously reacts at the catalytic surface. In this reaction, the carbon- hydrogen bonds are broken. The hydrogen atoms lose their electrons and become protons, also known as hydrogen ions, and migrate across the membrane to the gas side, the cathode. There, on the cathode's catalytic surface, they combine with oxygen from the air to produce water. The electrons given up on the anode side generate the current.
The carbon left on the liquid side is completely converted into non-toxic carbon dioxide. The cell is fuel-versatile, operating on methanol-derived fuels.
"A major problem with the existing device, however, is that the membrane used allows not just protons to cross to the cathode side, but also methanol, thus degrading performance and shortening the life of the cell," according to Sekharipuram R. Narayanan, who spearheaded the catalyst development work.
The Loker Institute's Drs. Prakash, Olah, Qungie Wang and Marshall Smart, along with JPL's Drs. Narayanan, Surumpudi and Halpert, have pioneered the development of improved proton membranes that will permit the construction of a new generation of cells achieving greater efficiency by blocking methanol migration. USC and JPL have applied for patents on these new membranes. The research team also hopes to drastically cut the cost of the proton exchange membrane, which is currently very expensive, the major economic roadblock to widespread applications.
Prakash, a professor in the department of chemistry in the University of Southern California's College of Letters, Arts and Sciences and at the Donald P. and Katherine T. Loker Hydrocarbon Institute, has collaborated with Dr. Olah, the Institute's director, for decades. Olah was awarded the Nobel Prize in chemistry in 1994 for his work with superacids, similar to substances used in the creation of the methanol fuel cell membrane.Olah has long maintained that chemistry can provide solutions to environmental problems while maintaining economic growth without destructive effects. "Both George and I think that this fuel cell is a prime example of this belief," said Prakash.
It was Prakash who in 1989 approached Surampudi of JPL seeking expertise in electrochemistry to design the cell and electrocatalysts to make the system work. Anthony Laconti, John Kosek and Cecilia Cropley of Giner Corp. were also involved in the development of the cell. "We think this new technology will bring the fuel cell down to earth for good," Prakash added.
JPL/USC, together with Giner Corp., is working on a contract from the Department of Defense to develop a 50-watt methanol fuel cell to replace lithium batteries used in various Department of Defense applications; a 150- Watt development program will begin in April, 1997. Other government entities involved include the Army Research Office and the Army Research and development command.
Harvey Frank, one of the co-inventors, has been working on fuel cells since 1960. Starting in 1989, the methanol fuel cell work was conducted by chemists Olah and Surya Prakash of USC and developed in cooperation with JPL researchers Halpert, Surampudi, Narayanan and Eugene Vamos, as well as the support of JPL team members Thomas Valdez, Andrew Kindler, Elizabeth Yen, William Chun, Barbara Nakamura and Albany Lee.
Licensee DTI Energy Inc. intends to develop a hybrid system for vehicular applications, according to President Todd Marsh. The fuel cells will be used to recharge continuously both conventional batteries and more advanced batteries, extending the range of the vehicles they power. "As we develop expertise in this area," he explained, "we will concurrently be developing a full range of applications, including stand-alone power, power generators, uninterrupted power supplies, and consumer electronic battery replacement, among others."
JPL's Technology Affiliates Program, which made the technology available for license to DTI Energy Inc., is designed to help U.S. companies improve their competitive positions in the global economy by transferring JPL technology into the marketplace. U.S. industry may tap the commercial potential of JPL's technology development activities via mechanisms ranging from reports, seminars, patent and software licenses to direct interaction with laboratory technologists. The nine-year-old JPL program now includes nearly 120 companies and has facilitated more than 200 technology transfer projects to benefit companies and the public. SOURCE Jet Propulsion Laboratory
CONTACT: John G. Watson of Jet Propulsion Laboratory, 818-354-5011, or http://www.jpl.nasa.gov; or Eric Mankin of the University of Southern California, 213-740-9344/ CO: Jet Propulsion Laboratory; University of Southern California ST: California