Lower Cost, CO2-Free, H2 Production from CH4 Using Liquid Tin

This project investigates the use of methane pyrolysis instead of steam methane reforming (SMR) for hydrogen production.

Currently, hydrogen production accounts for approximately 1 percent of global CO2 emissions, and the predominant production method is SMR. The SMR process relies on the formation of CO2, so replacing it with another economically competitive approach to making hydrogen would avoid emissions.

Henry and Barton’s work is a new take on an existing process, pyrolysis of methane. Like SMR, methane pyrolysis uses methane as the source of hydrogen, but follows a different pathway. SMR uses the oxygen in water to liberate the hydrogen by preferentially bonding oxygen to the carbon in methane, producing CO2 gas in the process. In methane pyrolysis, the methane is heated to such a high temperature that the molecule itself becomes unstable and decomposes into hydrogen gas and solid carbon - a much more valuable byproduct than CO2 gas. Although the idea of methane pyrolysis has existed for many years, it has been difficult to commercialize because of the formation of the solid byproduct, which can deposit on the walls of the reactor, eventually plugging it up. This issue makes the process impractical. Henry and Barton’s project uses a new approach in which the reaction is facilitated with inert molten tin, which prevents the plugging from occurring. The proposed approach is enabled by recent advances in Henry’s lab that enable the flow and containment of liquid metal at extreme temperatures without leakage or material degradation.