Spinoff is NASA’s annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.
In 2004, researchers at New Mexico Highlands University (NMHU) were developing a substance that would glow to indicate the presence of hydrazine — a toxic, flammable, unstable compound often used as rocket fuel. To their surprise, it didn’t just react with hydrazine, it neutralized the hazardous chemical.
It took more than a dozen years of investigation by NASA and others before the resulting ZeenKleen product — now marketed by Marietta, GA-based Hydrazine Neutralizing Solutions (HNSI) — began to make hydrazine cleanup and disposal cheap and easy for NASA, the military, and industries from power to plastics.
Since signing a Space Act Agreement with Johnson Space Center in 1997, the NMHU team had been working to improve a hydrazine-absorbing pad that Johnson’s White Sands Test Facility originally developed. They enlisted the help of Rudy Martinez, an organic chemist with Los Alamos National Laboratory who had recently started teaching at the university, and it was Martinez who hit on the formula that would later be commercialized.
The key ingredient was alpha-ketoglutaric acid (AKGA), an organic compound essential to metabolism and often used as a dietary supplement and wound-healing agent. Martinez’s interest was in its molecular configuration, which appeared ideal for reacting with hydrazine. “We found out the reaction takes pure hydrazine and neutralizes 99% of it within 15 minutes,” Martinez said. “We just kind of stopped working on the detector because we had such a great neutralizer.”
After some initial testing, the university contacted Chuck Davis, a hydrazine specialist at Kennedy Space Center. Hydrazine compounds “are really awesome propellants,” Davis said, noting that, as hazardous materials, their disposal is complicated and costly.
NASA has used hydrazine and its derivatives since the Gemini missions of the 1960s, primarily in smaller thrusters that adjust a spacecraft’s course or orientation. A monopropellant that combusts when exposed to a catalyst, hydrazine requires no ignition system and doesn’t need to be oxidized to power a thruster. Kennedy uses more hydrazine than any of NASA’s centers, producing about 15,000 gallons of hydrazine waste per year. Said Davis, “We can’t use it for flight anymore, so we’ve got to throw it away” — a complicated procedure for a substance considered hazardous to humans at concentrations of less than one part per million.
Davis’ interest in AKGA as an alternative for hydrazine cleanup prompted Kennedy to contact White Sands, where a round of testing was carried out in 2008. The study concluded that AKGA effectively neutralized both hydrazine and one of its derivatives, monomethylhydrazine (MMH), also commonly used for propulsion. Researchers confirmed that AKGA, when combined with hydrazine or MMH, yielded water and one of two pyridazinecarboxylic acids known as PCA and mPCA, respectively. These byproducts are relatively harmless and stable, and the reaction that produces them is irreversible.
Kennedy funded a series of experiments to determine the effectiveness and ideal procedures for neutralizing hydrazine and MMH with AKGA. Testing looked for any possible health or environmental impacts of the resulting PCA and mPCA and also determined that they would not inhibit sewage treatment if properly poured down a drain.
The work came to the attention of the Air Force, which uses hydrazine in the emergency power unit of its F-16 fighter jet. The possible impacts of disposing of PCA and mPCA through the sewer system were evaluated. Following those tests and Kennedy’s creation of procedures for disposal into the sewer, the Air Force, in 2015, obtained permits for the center to treat hydrazine with AKGA and dump the end product down the drain.
In 2013, the university licensed its creation to Millennium Enterprises, which founded HNSI to market it under the name of ZeenKleen. Martinez is the business’s director of chemistry. HNSI has found customers in about 10 nuclear power plants, where hydrazine is normally used in a 1 to 3% solution. In the case of a more concentrated spill, a standard industry treatment is to dilute hydrazine to about 3% by adding water and then use bleach to neutralize the diluted hydrazine. “This is so much safer than using bleach to neutralize hydrazine,” Martinez said. “With our system, you can spray down an area and walk away from it for a period, and it’s no longer hydrazine. It’s a material that’s safe to put down the common drain.”
HNSI sells ZeenKleen in liquid and powder forms, as well as in pillows and pads.