In practice, this game of topping up the carboncontent to make a better fuel stops with octanol (eight carbon atoms) as anything bigger tends to freeze at temperatures that might be encountered in winter.
Lehmann, the lead author of the paper which is published in the journal Nature Geosciences, said that the black carboncontent of soils in the study ranged from zero to 82 percent of soil organic carbon.
This gas contains approximately 80% of the original energy content of the coal, and is a combination of hydrogen, carbon monoxide, carbon dioxide, and methane.