Greener, more efficient process developed to produce hydrogen from natural gas
By Ben Coxworth
May 17, 2011
Hydrogen is certainly one of the big candidates when it comes to finding cleaner fuels to replace petroleum. While it only produces water when burnt as fuel, the process of obtaining hydrogen from natural gas is not quite so eco-friendly – it consumes a lot of energy, and creates carbon dioxide. Now a new process being developed at the Netherlands' Eindhoven University of Technology (TU/e) promises a much more efficient, innocuous alternative.
Traditionally, a process known as "steam reforming" is used to produce hydrogen from natural gas. It requires pressures as high as 25 bar (363 psi) and temperatures up to 850 C (1562 F), while also incorporating multistage subsequent separation and purification units. In the post-processing phase, large amounts of CO2 either must be dealt with, or are released into the atmosphere.
TU/e's Dr. Mohamed Halabi has created a system called "sorption enhanced catalytic reforming of methane," which uses unique catalyst/sorbent materials instead of steam reforming. The process takes place in a packed bed reactor, with hydrogen being produced on the Rhodium-based catalyst, and the cogenerated CO2 then being absorbed by the Hydrotalcite-based sorbent. This keeps the carbon from escaping into the environment, and results in "high-purity" hydrogen with carbon impurities of less than 100 parts-per-million.
The system's fuel conversion efficiency has been measured at 99.5 percent.
Energy requirements for the technology are relatively low, as temperatures need only be between 400 and 500 C (752-932 F), with a pressure of 4.5 bar (65 psi). Additionally, reactors utilizing the process could be much smaller than those presently in use, to the point that Halabi is envisioning systems that could be used in businesses or homes.