The maximum potential for the production of Renewable Gas depends a great deal on efficient, cheap methods of producing Renewable Hydrogen.
This is because increasing the fraction of hydrogen in a carbon-rich gas mix opens the way to a gas stream with a higher energy density – either with or without chemical reaction, heat treatment or refinery.
Although hydrogen gas is often considered as a replacement for hydrocarbon fuels, a mix of carbon-rich Renewable Gas resources with hydrogen offer a wider scope. For example, gas grid networks can certainly take around 5% hydrogen, and maybe even more, without altering gas distribution infrastructure or gas-burning appliances.
A number of materials are currently under investigation as catalysts for the electrolysis of water, which would mean inexpensive high volume production of hydrogen – these materials need to be plentiful in the Earth’s crust and relatively cheap.
A combination of computer modelling and physical experiment is pointing the way to several classes of chemical compounds and molecular compositions – such as nano-structures on substrates and metallo-organic matrixes (or should I say “matrices” ?)