Monday, April 08, 2013

Hydrogen from Methane Without CO2 Emissions?

The production of hydrogen from methane without carbon dioxide emissions is the objective of a project at the Karlsruhe Liquid Metal Laboratory (KALLA).  Researchers are setting up a novel liquid-metal bubble column reactor, in which methane is decomposed into hydrogen and elemental carbon at high temperature. Energy production from fossil fuels without emissions of climate-affecting carbon dioxide might come true through this research program.

Hydrogen represents a promising medium for the storage and transport of energy in the future. However, it is bound in water (H2O) or hydrocarbons, such as petroleum, natural gas or coal. Consequently, the hydrogen has to be separated first. In the course of conventional separation processes, the climate-affecting greenhouse gas carbon dioxide is formed. Today's worldwide hydrogen production causes about 5% of the global CO2 emissions.

The Center would like to explore combining this program with our Energy Defense Reservations (EDR) Program, which seeks to convert CO2 into diesel fuel.  It might also fit nicely with the Liquid Fluoride Thorium Reactor program, which utilizes liquefied uranium and thorium in liquefied salts to produce electricity.

CO2-free hydrogen production will be achieved by thermal decomposition of methane in a high-temperature bubble column reactor. The liquid-metal bubble column reactor to be built up at KALLA in the next months is a vertical column of about half a meter in height and a few centimeters in diameter. The column is filled with liquid metal that is heated up to 1000°C. Fine methane bubbles enter the column through a porous filling at the bottom. These bubbles rise up to the surface.  At such high temperatures, the ascending methane bubbles are increasingly decomposed into hydrogen and carbon.

In the reactor planned to be built, the shell of the bubbles assumes the role of the wall. Only when the bubbles burst at the surface of the liquid metal, is carbon released. The reactor wall is constantly renewed.  Again, any excess carbon could be utilized in our EDR to produce diesel fuel.  (Science Daily, 4/8/2013)

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