These briquettes are very different from charcoal because they do not have large concentrations of carbonaceous substances and added materials.

The spectra of carbon planets would lack water, but show the presence of carbonaceous substances, such as carbon monoxide.

The process for producing water gas (C + HO CO + H) has been known since the 19th century and it was later found that it is applicable to all carbonaceous substances.

Cendres-noires, the 'black gold' of the Montagne de Reims, is a Sparnacian deposit comprised almost entirely of rich black lignite, a friable carbonaceous substance which is half-way between peat and coal.

It is a high temperature furnace (as shown in figure 1), filled with steam and/or carbon dioxide gas and maintaining a thermal equilibrium at a temperature just above 1200 C, in which the reforming reaction is at its thermodynamic equilibrium and carbonaceous substance is reformed with the highest efficiency.