How green methanol can help us decarbonise

The engineers, from Siemens Energy, showed for the first time that green methanol produced from sustainable sources could power a gas turbine engine. The gas turbine used in this liquid biomethanol pilot is based on an original frame design first introduced in 1950. This promising milestone proved that gas turbines can be easily retrofitted to run on green methanol. According to the team responsible, shifting from conventional fuels to green methanol in a gas turbine can reduce CO₂ emissions by up to 75%.

What’s green methanol?

Ever cooked your holiday dinner on a camping stove? Or de-iced your car windows? Are your gym clothes made from synthetic fabrics? If the answer to any of these is yes, you are very likely to have come across a methanol derivate. Methanol is a versatile alcohol used in the production of many everyday items such as paints, solvents, plastics, car parts, and clothing. It is also used as an automotive fuel.

Similarly to hydrogen, colours are used to designate how methanol is produced. Regardless of the source, the resulting methanol has the same chemical structure.

• Brown methanol originates from coal.
• Grey methanol is made from natural gas.
• Blue methanol is made from blue hydrogen, which is produced from natural gas. The difference here is that carbon capture technology is used at the hydrogen production stage, as well as when the blue hydrogen is converted to methanol.

Then, there’s low-carbon green methanol, for which there are two types:

• Bio-methanol, produced from biomass or biogas from food waste.
• E-methanol, produced from renewable energy, water and captured CO₂.

Largely due to the current cost of production, the methanol generated today mainly comes from fossil fuels: 65% of the methanol available today is grey methanol, 35% brown methanol and just 0.2% green methanol. However, this is likely to change in the future as renewable power continues to decline in cost.

In order to advance towards a net zero future, we must reduce CO₂ emissions globally. So, it is hoped that green methanol will replace grey and brown methanol in its many current manufacturing uses, as well as in emerging applications. 

One of these emerging applications is shipping. Methanol is one of few viable solutions to decarbonise shipping, which is currently responsible for 2% of global greenhouse gas emissions. It’s thought that existing ships can be retrofitted to run on green methanol at moderate costs, and for new builds the investment is comparable to building new traditional ships. 

However, one of the key issues is ensuring there will be enough green methanol to go round. To this end, MAERSK recently announced a significant milestone – acquiring enough fuel for the maiden voyage of the first ever green methanol-powered container vessel.

In the meantime, further proof-of-concept studies are also needed to show e-fuels such as green methanol are a viable option. In one such example, Porsche and Siemens Energy have joined forces to manufacture e-fuels using renewable energy. In this ‘Haru Oni’ project in Chile, a 3.4 megawatt wind turbine powers the production of green methanol from carbon dioxide and water. It is then converted into synthetic fuels that will later be used to power combustion engines. Initially, the fuel will be carbon-neutral gasoline, but eventually, the facility will make e-methanol for shipping. 

As more pilot schemes get underway, momentum for green methanol will continue to build. Then, companies will begin to scale up manufacturing and roll the fuel out more widely.