Carbon: Hydrogen Carrier or Disappearing Skeleton?

Abstract

The use of liquid hydrocarbons as energy carriers implies the use of carbon as a carrier for hydrogen to facilitate hydrogen transport and storage. The current trend for liquid energy carriers used in the transport sector is to maximize the load of hydrogen on the carbon carrier. The recently developed Shell Middle Distillate Hydrogeneration process for the manufacture of high quality diesel from aromatic refinery streams fits this picture. In the future, the hydrogen required to raise the product's H/C ratio will be increasingly produced via gasification of large amounts of heavy residues. In the light of the strong preference towards using liquid fuels in the transport sector, the Shell Middle Distilliate Synthesis process to convert natural gas into diesel of very high quality is discussed. Finally, a few comments on the use of hydrogen without a carbon carrier are made. Long lead times and the likelihood of producing the "first" hydrogen from fossil fuel are highlighted