Synthetic fuels (or synfuels) are liquid or gaseous fuels that are practically similar to fossil fuels in everything but the way they’re produced. While conventional fossil fuels come from the process of organic matter being turned into coal, natural gas or oil, underground, over millions of years, synthetic fuels are produced artificially by replicating these natural processes, using renewable sources such as water, biomass, and carbon dioxide.

As the political demands for a carbon-neutral future (and mass electrification) get more persistent, many purists in the automotive industry keep clamoring for synthetic fuels to take over as a substitute for both fossil fuels and electric vehicles. Such is the case for Ferrari and Porsche, which are both heavily invested in e-fuels, a type of synfuel produced through electrolysis and seen as a suitable alternative to electric batteries. It is easy, at face value at least, to make a case for such an approach.

After all, synthetic fuels are what we call “drop-in” fuels. This means they are compatible with our internal combustion engines, and perfectly adaptable to the 168,000 gas-stations currently operating in the United States. On top of presenting a simpler option, they are also more eco-friendly than fossil fuels. Today, synfuels can be divided into three different types: e-fuels, biofuels, and solar fuels.

E-Fuels: Here To Preserve The Internal Combustion Engine

This is perhaps the most widely discussed type of synfuels right now. Electric fuels are produced from hydrogen, which is separated from water via a process known as electrolysis. This is in turn achieved using renewable electricity, which comes from wind and solar power plants.The hydrogen is synthesized into a liquid fuel using CO2 that has been taken from the atmosphere. This power-to-liquid modus operandi is known as the Fischer-Tropsch process.

Porsche Is Paving The Way

As electric vehicles have gained prominence, many experts and enthusiasts have gotten increasingly interested in e-fuels. While some see them as a threat to EVs, and a possible saving grace for internal combustion engines, others consider them to be in a losing battle against the inexorable rise of BEVs.

As of now, e-fuels are not yet produced at scale. It wasn’t until 2021that the world’s first commercial plant would open in Chile, backed by Porsche. The German manufacturer aims to eventually produce 550 million liters (145 million gallons) per year, but these figures are still a far cry from meeting the current demand in the United States alone.

Ferrari Wants To Follow Suit

In any case, the EU announced in March that some cars that are solely powered by e-fuels would be allowed to remain on sale after the 2035 ban on internal combustion engines. When asked about the decision, Ferrari CEO Benedetto Vigna described it as a favorable turn of events.

The strategy referred to by Vigna is one that includes various powertrains, which, to the delight of petrolheads, also includes internal combustion engines, as well as hybrids and EVs.

The Future Of Electric Fuels Is Still In Limbo

The proclivity towards electric fuels can be partly attributed to the fact that they represent a viable way to preserve internal combustion engines in the years to come. Moreover, they also allow countries with abundant amounts of solar and wind power to utilize and convert their natural resources into an alternative type of fuel that would diminish their dependence on foreign and local oil.

On the flip side, they also happen to be less efficient than electric batteries, and are only able to retain roughly 16 percent to 48 percent of the energy used. This means that their electricity generation requirements are two to ten times higher than their BEV counterparts, according to a study published by the Nature Climate Change in May 2021.

E-Fuels Won’t Replace EVs, But They Could Gain Momentum

Under the present conditions, it seems rather unlikely that e-fuels can become cheap and abundant early enough to replace fossil fuels on a broad scale. The study published by the Nature Climate Change journal strongly asserts that e-fuels cannot override the “urgent need for broad electrification”, and deems them unlikely to help reach the 2030 climate target. However, the research paper also judges e-fuels as likely to become a competitive option as technological advancements help reduce their processing costs over the years.

Biofuels: Liquid Fuels Derived From Organic Matter

The source of biofuels, known as biomass, refers to trees, energy crops, agricultural residue, and food and waste residues. Biofuels themselves are divided into two different types: Ethanol, and biodiesel. Unlike the other types of synfuels, both are widely found in commercial vehicles.

Ethanol Comes In Many Forms And Shapes

Ethanol is mostly made from plant starches and sugars, and it is even used as a blending agent in gasoline to increase octane and cut down emissions. It is conventionally used in the form of E10 (10% ethanol, 90% gasoline) and E15 (15% ethanol, 85% gasoline). Some vehicles known as “flexible fuel vehicles” are designed to run on an E85 formula (a gasoline-ethanol combo consisting of 51-83% ethanol.) The latter was in fact offered on the Bentley Continental GT back in 2010.

The Cons Of Ethanol

While ethanol is a cleaner and cheaper alternative that can contribute additional torque and horsepower, it nonetheless comes with a particular set of issues that have played a role in reducing its spread. The problems with ethanol notably are the following:

• It is more susceptible to dirt absorption
• Dirt absorption can in turn damage the engine and result in hefty repair costs.
• It can also require 1.5 times more to generate the same amount of energy compared to normal fossil-fuels.
• It offers fewer miles per gallon than normal gas.

Biodiesel: A Biofuel Combining Vegetable Oils And Diesel Fuel

This one is rarely used in its pure form, but rather blended with fossil fuel. The most common biodiesel blend is B20 (from 6 to 20% percent biodiesel combined with petroleum diesel.), while the B5 formula (5% biodiesel) is also commonly found in fleet vehicles. In the United States, it is mainly sourced from soybean oil, as well as algae, granola, and animal tallow.

The Pros And Cons Of Biodesel

Aside from helping reduce a country’s dependence on foreign oil, biodiesel-powered vehicles can also be 30% more efficient than petroleum-based diesel engines. Furthermore, biodiesel is also higher in lubricity than normal diesel, which consequently reduces the wear and tear on the internal combustion engine. This, however, can also work as a double-edged sword and result in fuel filter clogs. On top of that, biodiesel can also be more difficult to store, due to its vegetable-based source products.

As a result, it needs to be kept at the right temperature, as excessive heat and cold can significantly damage it. What is also worth noting is the fact that it is 1.5 times more expensive, which is part of why it hasn’t taken off as a more popular option. But still, biodesels are still used in a wide variety of vehicles, including:

• Range Rover Velar
• Chevrolet Silverado
• Chevrolet Colorado
• GMC Terrain
• Ford Transit
• RAM 2400, 3500, 45000, and 5500.

Solar Fuels: The Forgotten Alternative

This is the least known form of synthetic fuel, as well as the least popular in the automotive industry. As a matter of fact, it has yet to receive considerable interest from any manufacturer, as its development keeps stagnating at the infancy level.

Solar Fuels Are More Versatile And Convenient

As indicated by their name, solar fuels are made from substances like water and carbon dioxide using sunlight energy. Solar fuels can come in many forms, such as:

• Kerosene
• Gasoline
• Diesel methanol
• Hydrogen
• Synthetic crude oil

On paper, they would help make up for the intermittent availability of solar power, which has made the latter more expensive and difficult to harness on a grid-scale level. Furthermore, solar fuel would also provide an abundant source of liquid fuels to properly supply heavy-duty vehicles, ships, and aircraft, particularly in developing countries.

For Now, They Remain Overlooked By The Industry

While solar fuels are filled with potential, in theory at least, they still lack the technological means and financial backing to pick up the way biofuels and e-fuels have. This can be partly attributed to their costly nature. Under present conditions, making hydrogen from sunlight would turn out to be ten times more expensive than producing hydrogen using fossil fuels. This causes the need for more advanced technology that would cheapen the processing expenses.

Unfortunately, there is no clear indication that such progress would be feasible within the proper time frame. In the meantime, other alternatives are growing at a much faster pace. It will thus be interesting to see if solar fuels will ever gain the backing and momentum needed to ever become a fixture in the industry.