Synthetic fuels are likely to become the gold standard in shipping as soon as sufficient volumes come onstream
The curse of carbon emissions may become the friend of future fuels under a fast-developing science that bears the mysterious name ‘power-to-X’.
Still very much an emerging technology, power-to-X is the dream of visionaries who see the possibility of a 100% carbon-neutral era for energy.
“Power-to-X is going to play a key part in the future of energy generation,” said Wärtsilä’s senior manager for power-to-X, Tommi Rintamäki, in an early 2019 report entitled: Synthetic fuels: supporting Wärtsilä’s vision of a 100% renewable future.
MAN Energy Solutions is equally bullish: “By coupling the major energy sectors, power-to-X will play a major role in creating a truly carbon-neutral energy system,” the company enthuses.
Power-to-X is all about synthetic fuel being extracted from unwanted CO2 emissions or other waste forms of energy. As Wärtsilä explains, an extra benefit is that “new fossil resources are prevented from being exploited for fuel.”
Most of the oil and gas giants are working on power-to-X, some of them in collaboration with private laboratories. For instance, ExxonMobil, Shell, France’s Air Liquide and Pennsylvania-headquartered Air Products and Chemicals recently combined resources to develop the capture, transportation and storage of CO2 at the Port of Rotterdam. The plan is to store the CO2 for future use beneath the North Sea by the end of 2023.
Pie in the sky? Hardly, if we look at the way the renewable energy industry has confounded all predictions. The unsubsidised cost of wind and solar has fallen so low that renewable energy hubs are putting coal-fired power stations out of business in the United States at the rate of one a month. Nobody foresaw that happening in 2010.
Power-to-X is an umbrella term that encompasses a whole range of sciences and technologies, all of which are based on the harnessing of surplus power. As Wärtsilä explains, there are three key ingredients in the capture and conversion of CO2 – the CO2 itself, hydrogen and renewably made electricity.
The hydrogen is obtained from water through the process of electrolysis that splits into hydrogen and oxygen. There are already thousands of hydrogen-powered buses around the world and several shipping companies are trialling hydrogen power units.
Carbon capture is much newer. The science grabs CO2 emissions from smokestacks or, even better, directly from air. The tricky bit is known as chemical synthesis whereby hydrogen and CO2 are combined into a synthetic fuel with the use of catalysts. The result, which will become familiar to enginerooms, are hydrocarbons or alkanes such as methane, methanol and dimethyl ether (DME).
“All of these can be used as fuel across a variety of power generation and transportation applications,” summarises Wärtsilä’s Mr Rintamäki.
He continues: “[We] envisage a future in which it will be possible to capture the CO2 that is emitted from combustion processes from the air and re-circulate it in what could potentially be an infinite energy loop.”
Wärtsilä has already begun embedding power-to-X technologies into its future products and services. It is also collaborating with start-ups such as Icelandic Carbon Recycling International, which is focusing on the production of synthetic methanol. At this stage, Wärtsilä believes that synthetic methane will best suit gas engines while synthetic methanol and DME will be used for diesel engines with dual-fuel pilot injection.
And the timing? A consensus of experts assume synthetic fuels will become available in industrial volumes within the next five to 10 years, just in time for the next round of IMO emissions regulations.