Carbon dioxide reforming (also known as dry reforming) is a method of producing synthesis gas (mixtures of hydrogen and carbon monoxide) from the reaction of carbon dioxide with hydrocarbons such as methane. Synthesis gas is conventionally produced via the steam reforming reaction. In recent years, increased concerns on the contribution of greenhouse gases to global warming have increased interest in the replacement of steam as reactant with carbon dioxide.
The dry reforming reaction may be represented by:
CO2 + CH4 → 2 H2 + 2 COThus, two greenhouse gases are consumed and useful chemical building blocks, hydrogen and carbon monoxide, are produced. A challenge to the commercialization of this process is that the hydrogen that is produced tends to react with the carbon dioxide. For example, the following reaction typically proceeds with a lower activation energy than the dry reforming reaction itself:
CO2 + H2 → H2O + COTypical catalysts are noble metals, Ni or Ni alloys. In addition, a group of researchers in China investigated the use of activated carbon as an alternative catalyst.