A chat with Alex G. Fassbender
New technologies for treating wastewater are being developed at a fast and furious rate. Yet often there are decades of experimentation behind those deceptively ‘instantaneous’ leaps.
Wastewater and ammonia—a long history
One such product is an ammonia removal process. Alex G. Fassbender remembers starting work at a Pacific northwest lab back in 1976, where the environmental group was striving for a solution to ammonia—and at that moment, they had been working on the problem for 20 years and counting. “How to take it out of water, essentially, was the key question,” he recalls.
Easily formed and ionized but hard to separate, ammonia removal was an ongoing challenge. Nitrogen and oxygen are right next to each other on the periodic table, Fassbender explains. “They weigh the same and are very similar, with an affinity for each other.”
Many methods and processes were tried and much investigative work was carried out, he remembers. At one point, the Monsanto Company issued the now-famous ‘Monsanto Challenge’ seeking ways to separate ammonia from water and offering a considerable bounty for same.
Fassbender and some fellow engineers and chemists were convinced there had to be a way to remove ammonia by capitalizing on its affinity for transition metals (zinc and copper), where it will form interesting complexes. “We began working in that direction, hoping to harness and encourage that, but nothing really worked. There’d be some effect, but very feeble,” he said.
Modern solution
Chemist Scott Blonigan realized the kernel of what would become ThermoEnergy Corporation’s Ammonia Recovery Process (ARP), which is (simply defined), “That you can take standard acid cation resin, load it full of zinc molecules with a double plus charge. Which sticks really nicely like they were made for each other—and literally, they were—rinse and pour ammonia-laden water over it and that ammonia will stick to the resin,” Fassbender explains.
Those simply defined basics are, in fact, an incredibly powerful process. In one location (Oakwood, N.Y.), filtered concentrate with 1,200 parts per million (ppm) ammonia came out non-detectable. “At high concentrations 20,000 ppm liquid vapor equilibrium technologies can get you to a lower level, but still have a way to go and can’t discharge it,” Fassbender notes. “Using this new process in waste water plants with anaerobic systems in place, followed by dewatering operations, 17-25 percent of the ammonia can be removed.”
A viable—and valuable—by-product
Operating as a complete regeneration scheme, facilities can take the ammonia off, leave the zinc and recover the ammonia (in the form of an ammonium sulfate product). Depending on the economics, it can be used as fertilizer, either in liquid solution or dried. Lately, that aspect is of particular interest, as the United States is becoming dependent on foreign ammonia since the domestic fertilizer industry shut down because of the tremendous rise in the cost of natural gas (from which most ammonia was made). Trinidad and Tobago (and a few other places with large natural gas resources) now effectively control the fertilizer market and the products are priced to the point of pain. “But such is capitalism,” Fassbender opines, “As natural gas-fired ammonia plants all over the U.S. are shutting down, recovering ammonia from waste water is a big deal now, as an income-generating commodity.” In fact, ThermoEnergy clients report that agricultural cooperatives find them and call them out of the blue to inquire about purchasing opportunities.
A uniquely simple solution
Municipalities need to deal with the nitrogen issue and this is a very elegant solution. It takes up very little space and has a big impact on the plant. It also reduces the amount of energy used, the carbon/nitrogen ratio is helped and it generates this saleable commodity as a by-product.
“We take this waste product, sulfur. There’s mountains of it, the price in North America is cheap. We use sulfuric acid, mix with zinc and wind up with an ammonium sulfate product and market it directly for agricultural use. The neat thing about using zinc is that it is very friendly, nothing hostile. Sulfuric acid, of course, requires care—but we can deal with that,” he sums up.
The process is simple, relying on pans, pumps, pipes and vessels. From contract signing forward, it’s roughly a year or less to completion from engineering through design/build. Cities pay for performance. “We take their stream, remove the ammonia and return it to them,” Fassbender explains. “If cities go biological, they get married to methanol, which is also made from natural gas. That requires a lot more space and they have to buy the commodity forever.”
“While it seems to have all happened very quickly, it’s worth noting that back in 1976 the only way to measure ammonia water was the Kjeldahl Method—talk about the Stone Age!” he recalls with a laugh.
Yin and yang
Fassbender believes it all becomes obvious if you overlay two curves. Historically, start with Franz Haber’s work in 1993 and Haber and Carl Bosch’s Nobel Prize-winning developments in 1933. Track the production of human-made nitrogen on a scale of years, 1900-2006 and on the other, the world population. Overlay those two curves and they should lay right on top of each other. “You’ll see that our whole system on this planet is dependent on nitrogen produced initially as ammonia. To simply throw it away or spend money to destroy it in a world of scarce resources is foolish when we can use it to support the six billion people sharing this Earth,” Fassbender concludes.
About the company
ThermoEnergy is an integrated technologies company that provides cost-effective and environmentally responsible solutions for clean air and water process systems. Core business is the design, fabrication and operation of patented and/or proprietary municipal; ad industrial waste water treatment and power generation technologies including the Ammonia Recovery Process® (ARP), Thermo Energy Integrated Power System® (TIPS) and the newly patented Thermo Fuel, which converts sewage sluge into a bio-fuel. For more information, or to contact Alex Fassbender, visit the company’s website, www.thermoenergy.com or email him at [email protected]