UB engineering professor lands $1.5 million grant to create clean hydrogen

Producing clean hydrogen is one way to address climate change that is threatening the planet. It can be used in a fuel cell or gas turbine to create electricity with only water and heat as byproducts.

There is just one problem: More than 95% of the roughly 10 million metric tons of hydrogen currently produced in the United States comes from natural gas, which results in significant emissions.

Haiqing Lin, professor and director of graduate studies in the Department of Chemical and Biological Engineering, is working to change this percentage.

Lin and his research team were recently awarded $1.5 million in funding, including $1.17 million from the U.S. Department of Energy (DOE), for a two-year project that is scheduled to begin on April 1. They will develop a membrane to separate different elements in the air and support gasification-based hydrogen production. (Electricity generated from clean hydrogen will help reach the Biden-Harris administration’s goals of achieving a zero-carbon American power sector by 2035 and a net-zero emissions economy by 2050.)

Lin’s technology employs a membrane consisting of a bundle of selectively permeable hollow fibers that separate oxygen from nitrogen. If successful, the membrane would produce pure oxygen at a lower cost than cryogenic-based air separation. The pure oxygen would, in turn, be used to produce low-cost hydrogen from biomasses or wastes at distributed locations. Ultimately, the technology could reduce carbon dioxide emissions and spur economic growth and domestic job creation.

“Conventionally, you produce pure oxygen through a cryogenic process,” Lin explains. “You take air, remove water and bring the temperature down to a very cold level. It’s quite an energy-intensive process, particularly at small scales.”

Lin and his UB team, composed of a postdoc and a graduate student, are working with colleagues at the University of Texas at Austin and Trimeric Corp., a small engineering consultant company in Austin. The UB team will develop the new materials while the UT team, led by Lin’s former doctoral adviser, Benny Freeman, will optimize, fabricate and test the hollow fiber membranes. Trimeric will perform the membrane process simulation and economic analysis.

Lin’s group has been looking at three approaches to mitigate CO2 emissions to the atmosphere.

“The first approach is to figure out how we can capture the CO2 from the flue gas before it gets into the air,” he says.

The second approach is to convert fossil fuels to hydrogen, called decarbonizing, before the use. And the last approach is to generate pure oxygen first, then use oxygen for combustion with natural gas or biomass.

“The challenge for the last approach to work is to find a way to produce pure oxygen from the air in an environmentally friendly way,” Lin says. “Membranes have been used mainly to produce nitrogen, not oxygen. The reason they are not being used for oxygen production is that they do not have high oxygen/nitrogen selectivity. In that process, the oxygen product is not pure enough.”

The key contribution to this project, he says, is finding the membranes with an oxygen/nitrogen selectivity of 15, which is about two times higher than currently found.

“In this process, the membrane is like a magical layer, which allows oxygen to go through but not nitrogen,” he says. “The goal of this project is to develop the magical layer. We’re looking at creating it through polymer-based materials.”

Lin notes the project is very difficult and ambitious.

“Hopefully, we will be successful, but there is no guarantee,” he says. “If we can’t achieve a selectivity of 15, maybe we’ll reach 10 or 12, which is still a great improvement over what we have now.”