Tokyo Gas Co Ltd, Japan's top city gas supplier, said on Friday it has begun a pilot program of methanation, a technology to help decarbonize city gas, and plans to use green hydrogen sourced from renewable energy for the trial by next March.

Methanation converts hydrogen and carbon dioxide (CO2) into synthetic methane, an alternative for the main component in natural gas. It is considered a way of using CO2 as a raw material that could help the company achieve carbon neutrality in 2050.

Methane can be used in many ways, including as a fuel to generate heat and electricity in power plants or at home, and as a raw material for the chemical industry.

For the first-phase trial aimed at producing 12.5 normal cubic metres per hour (Nm3/h) synthetic methane, Tokyo Gas has installed Hitachi Zosen's methanation device at its research centre in Yokohama, near Tokyo, and begun producing the fuel from hydrogen and CO2 procured from outside.

It plans to install a water electrolysis device from Britain's ITM Power and use renewable-based hydrogen to produce synthetic methane by March, Hisataka Yakabe, Tokyo Gas's executive officer, said during a media tour of the facilities.

It will also use CO2 emitted and captured from nearby factories or its customers.

Tokyo Gas is aiming to replace about 1% of city gas volume with synthetic methane by 2030. It will scale up the trial in late 2020s to produce 400 Nm3/h, followed by an overseas demonstration in 2030 to make 20,000 Nm3/h.