NuMat Technologies

Compressing, storing, and handling gases is so commonplace in industry, by some measures it accounts for 10% of the global energy draw.

Yet today’s cylinders are by and large processed, filled, and used much the same as cylinders from earlier generations. A small group of entrepreneurs in a Chicago-area start-up thinks it’s time for a change.

NuMat Technologies is betting that modifying the interiors of cylinders and other gas equipment with custom-made nanomaterials known as metal-organic framework compounds, or MOFs, can significantly improve the way gases are stored, separated, and purified. The company’s goal is to offer a safer and less energy-intensive way of handling gases.

Since the early 2000s, MOFs have shone in the scientific spotlight because of their outstanding properties. These porous crystals, which are composed of metal ions or clusters bridged by organic linking groups, boast record-setting internal areas, exceptional gas-uptake capacities, and the ability to selectively adsorb one gas in the presence of others. For example, 1 g of a MOF developed by NuMat founder Omar Farha would, unfolded, cover an area the size of one-and-a-half football fields, leaving open tremendous internal volume for gas uptake.

Chemists specializing in porous materials marveled at MOFs’ properties and soon began designing and making a great variety of these materials. They recognized that through chemical synthesis, MOFs’ gas storage properties could be tweaked and tuned by, for example, judiciously choosing among an enormous number of possible organic linking groups.

Farha was one of those researchers. He developed expertise in MOFs during his postdoc and subsequent years as a research professor at Northwestern University. In 2013, Farha cofounded NuMat and now serves as its chief science officer.

Initially, the company focused on low-pressure natural gas and hydrogen storage for vehicles, says NuMat CEO Benjamin Hernandez. Studies had shown that gas cylinders filled with some types of MOFs could store nearly twice as much gas as unfilled cylinders at comparable pressures, thereby safely extending a vehicle’s driving range. NuMat secured funding for that line of work. But as Hernandez and coworkers soon realized, success in “the incredibly complex hydrogen-powered vehicle market” depends on many factors beyond the control of a high-tech start-up.

So they shifted gears, focusing instead—at least for now—on designing and building systems that can safely store and deliver reactive gases such as arsine, phosphine, and boron trifluoride. These highly toxic gases are used in the electronics industry for implanting ions in semiconductors to tailor their properties.

NuMat now offers a line of MOF-customized gas cylinders, which the firm prepares in-house using proprietary materials and methods. Compared with cylinders without sorbent material, NuMat’s Ion-X cylinders can hold comparable quantities of gas at far lower pressures. The lower pressures minimize chances of leaks and the rate of toxic gas escape in the event of a leak. MOFs can also stabilize reactive gases, preventing them from dimerizing and becoming unusable. And MOFs can also serve as traps for impurities, providing an inexpensive way to meet the electronics industry’s high-purity demands.

Already, a number of major gas-using companies have begun testing NuMat cylinders for electronics applications, Hernandez says. And in September, NuMat announced a partnership with Linde, a global gas supplier, to develop MOF-based gas storage and separation technologies. Now the company is gearing up to make inroads in agriculture, which uses toxic gas fumigants, and in the aerospace industry, with an application in oxygen storage.

CORRECTION: This story was updated on Nov. 21, 2016, to indicate all of NuMat’s founders.