Southern California Gas Co. (SoCalGas) introduced an innovative new solar-powered hydrogen generation system during the California Air Resources Board Technology Expo and Symposium at the University of California, Riverside. The project is a partnership between SoCalGas, Pacific Northwest National Laboratory (PNNL) and the STARS Corporation. The generation system uses sunlight to convert natural gas and water into hydrogen and capture the carbon dioxide (CO₂) to prevent carbon emissions.

A separate SoCalGas research and development project is studying the production of carbon nanotubes (CNTs) from carbon captured during hydrogen production. (Earlier post.)

Developed at Pacific Northwest National Laboratory (PNNL) (earlier post), the Solar Thermochemical Advanced Reactor System (STARS) produces hydrogen through a thermochemical process in which the sun provides thermal energy to break down natural gas and water into hydrogen and carbon dioxide in a steam methane reforming process.

The STARS technology is based on micro- and meso-channel processing technologies (MMPT) that have been demonstrated on a variety of different reactors and heat exchangers for intensifying processing applications. Using MMPT arrangements there are multiple applications under consideration for STARS, including the production of syngas, hydrogen, and methanol, using steam-methane reforming and dry reforming approaches.

Results from extensive testing show STARS can be configured to produce hydrogen and other chemicals without any carbon emissions reaching the atmosphere. These chemicals trap and use the carbon that would otherwise be emitted. The carbon then can be used to make chemicals that become resins and plastic materials.

STARS converts a record-setting 70% of solar energy into chemical energy.

The PNNL-spinoff company that licensed the technology for commercialization, STARS Technology Corporation (STC), is made up of three former PNNL employees, as well as their long-time industry mentor. The STC principals were participants in DOE’s inaugural Energy I-Corps, a two-month business training program-where they graduated best in class and transferred the knowledge gained into formation of their company.

STARS Corporation hopes to have a commercial demonstration operating in one to two years.

This technology is undergoing field testing at San Diego State University’s Brawley campus where it runs on solar and renewable electricity. Currently the system produces about 25 kg of hydrogen per day if operated around the clock using a combination of solar energy and renewable gas or electricity. This is the equivalent of 25 gallons of gasoline or diesel fuel. Research suggests the system could produce 100 kg of hydrogen per day with a more advanced design.

The STARS generation system has been in development by PNNL and the US Department of Energy (DOE) for more than 10 years. SoCalGas is working with the DOE to make these systems commercially viable.

SoCalGas supports efforts to increase hydrogen production, particularly for use along “California’s Hydrogen Highway,” a series of hydrogen-fueling stations throughout the state. Currently there are 35 hydrogen fueling stations in the state, with another 29 stations in development. Increasing this fueling infrastructure could help speed the deployment of zero emission hydrogen fuel cell vehicles which can play a significant role in reducing California’s greenhouse gas and smog emissions, according to the California Air Resources Board (ARB).