Can synthetic fuel replace fossil fuel globally?

Spirit Racing’s Mazda Demio runs on a cooking oil-based biofuel.

Human nature (take the easiest route) and financial considerations (take the most profitable route) are arguably the two things that drive society forward. That’s especially true when solving the world’s problems, such as global warming.

Electrification of cars ticks both boxes but raises the question of whether the early decision to abandon combustion engines misses a trick. The world’s biggest oil producers potentially stand to lose the most because alternatives might rule them out. While they may have a grip on the expertise and resources to drill for and produce petroleum products, the same isn’t true for other energy sources. Yet they are well placed to invest more in ‘drop-in’ carbon-neutral synthetic fuels, which can be dispensed using existing filling station forecourts without the need to create an entirely new infrastructure.

Experts have been saying for years that the fastest way to reduce CO2 from transport is to switch to a sustainable, carbon-neutral, synthetic liquid fuel that existing vehicles can run on. ‘Drop-in’ means that, unlike petrol heavily dosed with ethanol, there can be little, if any, downside. If the world’s vehicles could fill up with fuel synthesised from organic materials tomorrow, atmospheric CO2 derived from transport fuel would all but vanish overnight.

The Volkswagen Group is one of the manufacturers that have been pursuing the development of synthetic fuels for a couple of decades. Porsche is among the latest to stick its head above the parapet with a racing project and now Mazda, which last year became the first car manufacturer to join the eFuel Alliance, is taking an interest.

Like Porsche, it has taken to the race track to help develop and promote the use of synthetic fuel. In Mazda’s case, a 1.5-litre Skyactiv-D diesel engine, rather than a petrol engine, powered a race-prepared 2. 

The Mazda runs on Susteo, a synthetic fuel supplied by partner Euglena, and the raw materials needed to make it are used cooking oil (90%) with oil and fat extracted from the microalgae, called euglena, making up the balance. The use of vegetable oil doesn’t mean vehicles run around smelling like a fish and chip shop. It’s just a source of sustainable, waste bio-material that can be converted into synthetic petrol or diesel.

It’s CO2-neutral because the plants used to produce it gorged on CO2 from the atmosphere while growing. However, the aim is to move entirely towards algae as the source. It can be grown on land unsuitable for agriculture and doesn’t compete with food production.

A lot would be needed to replace the world’s consumption of petroleum oils, though. Road transport consumes around 1.3 billion gallons of petrol and diesel per day globally but, that said, the figure for vegetable oil is around 140 billion gallons. Put that way, the idea of producing enough guilt-free liquid fuel from algae to power existing combustion engines doesn’t seem like such a stretch.