Instead of traditionally expensive and difficult methods of removing salt and other impurities from seawater, Max wants to do it naturally. Hydrate crystals are composed exclusively of gas and water molecules, ergo no salt. Yet without

something holding the crystals down, natural-gas hydrates will float up from the deep because they are less dense than the surrounding salt water. (Hydrates formed with carbon dioxide, however, will sink because they are denser than most seawater.) As hydrates rise toward the surface, seawater pressure diminishes, forcing the crystals to melt. That unlocks the gas from its icy cage, a cage made of freshwater. Because that newly released water is less dense than both seawater and hydrate-seawater mix, it will rise as well.


Audra Ames, a hydrate expert at Marine Desalination Systems in St. Petersburg, Florida, monitors the transformation of seawater into hydrate. First, ethane is pumped into the bottom of a tube filled with pressurized salt water.

Fast-forward from that first lightbulb moment with the video through a couple of years refining the idea, patent approval, and the formation of Marine Desalination Systems in 1999 to the procurement of federal funding in 2001, and Max is in St. Petersburg, Florida, with a lab in a refurbished 1927 art deco building where Sealtest once made cherry-vanilla ice cream.

Max’s concept for a freshwater reactor is a giant column in the ocean or along a coast, perhaps 1,000 or 1,500 feet long, with pressurized gas pumped in at the base to foster hydrate growth and create what looks like a dynamic four-layered cocktail: seawater and hydrates at the bottom, hydrates rising and melting in the midsection, pure water in the upper area, and gas at the very top. The market-ready freshwater would be pumped out, and the gas would be recycled. The idea is reminiscent of a perpetual motion machine, says Kvenvolden. “It is so visionary. I don’t know why I didn’t think of it!”

The simplicity of the system gives it a Zen-like aura that makes Max a little giddy. “There’s almost nothing an engineer would recognize,” he says. “We don’t filter or pressurize anything.” The fundamentals are sound, says Ed Peltzer, a hydrate expert at the Monterey Bay Aquarium Research Institute. “It is a really elegant application of some pretty esoteric chemistry.”

Hydrate crystals, made of hydrocarbon gas and molecules of salt-free water, form and float upward in the vessel. At the top of the tank, under lower pressure, the crystals could be made to melt, unlocking potable water.

If it works. The concept of using hydrates is brought up every few years as if it were a new idea, says Raphael Semiat of the Rabin Desalination Laboratory at the Technion-Israel Institute of Technology. “But it is not new.” For more than two decades, researchers have seen the potential energy savings of this approach. But efforts to use hydrates for desalination have all failed for the same reason. They produced thin shells of hydrate surrounding gas bubbles. When that happens, too much seawater clings to the crystal clumps, creating a slurry mess. It is nearly impossible to sequester much freshwater from slurry because the crystals have to be washed clear of residual salts.

“Liquid will stick in a crystal system,” says Kevin Price, a water-treatment expert with the U.S. Bureau of Reclamation. “Can he [Max] guarantee that his system is different? If not, he will need to wash the crystals.” Jim Birkett, a water-technology consultant and former president of the International Desalination Association, recently purged all the hydrate-related literature from his office, deciding once and for all that the concept has no future.

“Everyone failed because they formed slurry,” concedes Max. “But we go completely around that.” The masterstroke is the long column. Because natural mechanisms drive the desalination process, Max says, there is no need to mechanically remove crystals or hydrate chunks from the seawater. And thanks to the natural gradient within the shaft, only the purest water floats to the top, while any salt entrained within the clumps of hydrate floating upward will not qualify, so to speak, for the uppermost batch of freshwater.

But Max agrees that the column alone will not guarantee a slurry-free process. He will need bulky hydrate crystals to do that. He says he’s close, using a technique he will not discuss. What he will share is part of his strategy for growing hefty hydrates: Increase the concentration of gas to saturate the seawater. He uses ethane as a proxy in the lab but will probably use mostly methane with a little ethane for the real thing. Instead of just bubbling the gas into the system, which would result in candy-shell crystals and a quick trip to Slurryville, Max plans to carefully dissolve the gas into the seawater.

“We’ve proved seawater pumped up with gas can make a lot of hydrate,” says Sarah Holman, who is a soft-spoken counterweight to Max’s bold personality. “Other labs, using fresh or distilled water, wait days for small amounts of hydrate to form.”