A new technology that generates hydrogen from conventional natural gas, or renewable natural gas made from biomass, could advance California’s Hydrogen Highway, fuel cell vehicles and trucks and to create other valuable products.

Tiny channels—about the width of a credit card—that transfer heat underpin the technology developed at the U.S. Department of Energy’s Pacific Northwest National Laboratory. These micro channels are critical to efficiently driving the energy into the chemical reactions that produce hydrogen for transportation, electricity generation and other industrial purposes.

The PNNL-developed hydrogen generator was licensed to a Richland, Wash. cleantech start-up company, STARS Technology Corporation. The hydrogen generator features two recent innovations that may drive down the cost of hydrogen. The first is a new additive manufacturing process that has been licensed to both STARS TC and SoCalGas—a Los Angeles-based gas distribution utility that serves 22 million people in Central and Southern California.  The second is a novel spiral reactor design that distributes heat more precisely and improves the reactor efficiency. This design, exclusively licensed to SoCalGas, minimizes the energy required to produce hydrogen while increasing the reactor’s durability and safety.

Fueling hydrogen infrastructure

Because the STARS technology can generate hydrogen anywhere natural gas is available, developers say this technology can greatly reduce the need for hauling hydrogen in special high-pressure tube-trailers.  Eliminating on-road transit improves public safety, reduces greenhouse gas emissions and helps make point-of-use hydrogen production cost competitive with conventional fuels.

“Think of these small, efficient, mass-produced generators as ‘chemical transformers’ similar to electrical transformers on the electric grid,” said Bob Wegeng, president of STARS TC and an inventor of the technology. “They can be placed anywhere along the natural gas distribution system, so it becomes a ‘hydrogen grid’ by providing inexpensive hydrogen for filling stations in quantities that match on-site demand."

This spring, SoCalGas will receive a hydrogen generator from STARS TC, which will include six small modular reactors—each about 10 inches in diameter. STARS TC is largely comprised of former PNNL staff, one of whom was an original inventor of the microchannel technology at PNNL.

3D printing to lower cost of hydrogen production

Recently, PNNL, STARS TC and SoCalGas collaborated on advancements to the hydrogen generation system, including the spiral microchannel design. This team has also developed a novel process that uses 3D printing methods to build the hydrogen-producing chemical reactors.

“This additive manufacturing process lowers manufacturing costs by reducing parts, forming geometric shapes that would be nearly impossible to create by casting or machining processes and eliminating time-intensive fabrication steps,” said Sara Hunt, a technology commercialization manager at PNNL. “The patented technology includes unique approaches for building structures within the device to enhance heat transfer. It also enables the material to be coated or impregnated with catalysts that speed up the rate of chemical conversion to energy.”

Separately, PNNL, SoCalGas and others are also collaborating on new chemical reactors that co-produce hydrogen and solid carbon materials, such as carbon fiber products and carbon nanotubes, which can offset the cost of greenhouse gas-free hydrogen production even further. This combined with the additional use of renewable natural gas means these reactor systems could help SoCalGas as it strives to net-zero emissions by 2045.

Development of the microchannel technology hydrogen generator has been supported by the RAPID Institute and offices in the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy, including the Hydrogen and Fuel Cell Technologies, Solar Energy Technologies and Advanced Manufacturing Offices.