Is Porsche's 'clean' fuel plant the future of the combustion engine?

Two years after it was announced, Porsche and its partners have switched on a pilot version of their Chilean e-fuels plant and started to create the controversial “clean” fuel for combustion engines.

The wind energy-powered plant was inaugurated by Porsche executives on 20 December, with the filling of a 911 sports car with the first litres of fuel produced at the plant. The facility is operated by Chilean company Highly Innovative Fuels (HIF) and Porsche says its current investment in the project stands at $100 million (£82 million).

“Porsche is committed to a double-e path: e-mobility [battery electric] and e-fuels as a complementary technology – using e-fuels reduces emissions,” said Barbara Frenkel, Porsche’s director for procurement.

Porsche estimates that when the fuel is in mass production in or around 2026, the price per litre at today’s costs would be about $2 (£1.65), perhaps a bit lower.

The German luxury car maker plans to use the fuels resulting from this pilot study in racing cars, vehicle trials and eventually production sports cars. In this pilot phase, about 130,000 litres of e-fuels will be produced. In two further phases, capacity will be increased to about 55 million litres a year by 2024, and about 550 million litres annually by 2026. By way of comparison, according to the RAC Foundation, in 2021 Britain consumed 14,683 million litres of petrol

Fuel production

The fuel starts life as the wind driving wind turbines constructed in the Magallanes Province on the extreme south of Chile’s 2,700-mile length, where the wind blows hard (some sites have average wind speeds of well over 22mph) and frequently (more than 6,000 hours in a year).

The resulting renewable electricity is used to electrolyse water into oxygen and hydrogen with electrolysers from Siemens Energy. The “green” hydrogen is then combined with carbon dioxide captured from the atmosphere to form synthetic methanol. Consisting of four parts hydrogen, one part oxygen and one part carbon, methanol is seen as an excellent hydrogen carrier. This process would be done with an MAN-supplied methanol synthesis reactor based on a Johnson Matthey design.

The methanol is converted into synthetic pump fuel using a methanol-to-gasoline process by Exxon Mobil’s fluid-bed methanol-to-liquid-fuel process, in which methanol feedstock is vapourised and superheated through a series of heat exchangers then fed into the fluid-bed reactor for conversion into hydrocarbons and water. The heat required is partly provided from heat generated in other parts of the production process such as the electrolysers. The resulting fuel will then be shipped to Europe.

Other partners in this project, named Haru Oni, are the energy firm AME and the petroleum company ENAP from Chile, along with Italian energy company Enel.

Inefficiencies stack up

Michael Steiner, Porsche’s research and development director, admits that the process is convoluted and that inefficiencies can stack up. Another electricity-to-fuel process is claiming overall efficiencies of up to 60 per cent: Steiner says the Haru Oni project isn’t even close to that figure. 

He says there is a need for e-fuels, however, pointing to Europe’s deficiency in energy, which will involve us importing energy in future whether we like it or not. He also says that the methanol could be exported in tankers for refinement at the country of consumption, although this would have to be done at carbon neutral refineries or the benefits will be lost.

“Electric vehicles in Europe would be by far the best solution,” says Steiner, “but the question is how we import energy in future and is that energy fossil or renewable.”

He also says that with 1.3 billion combustion-engined vehicles in the world with a life of 10 to 20 years, “we need to find ways to significantly reduce CO2 emissions from this fleet”.

There are also concerns for certain parts of the motorcycle market, particularly touring and adventure machines, where battery technology is incapable of replacing combustion engines while retaining a practical capability.

The moral question

Clearly there are moral questions about the exploitation of Chile’s natural wealth in renewable energy (the country also has considerable potential for other renewable energy generation with geothermal power and massive solar energy potential), for us to boast about how green we are driving around in our sports cars and big motorcycles, but centring the entire fuel production in Chile does mean valuable foreign currency sales and, just as importantly, local employment.

Nor is the resulting fuel entirely CO2-neutral. The heavy fuel oil used by tankers to ship the e-fuel to Europe or North America needs to be factored into the calculations, though Steiner asserts that “the fuel used in transportation is very small”. He also says that the process could be centred on anywhere with an excess of renewable fuel, be it wind or solar energy.

“You could have other plants wherever it makes sense,” he says.

Combustion engines using e-fuels will still produce exhaust emissions such as particulate matter and oxides of nitrogen, though again Steiner says that Porsche’s own measurements show that “there is no significant impact in NOx or particulate matter in e-fuel-burning engines”.

Legislation for the future

In the end Steiner says that the potential of the fuel and the possible expansion of production to other sites is dependent on incentives and taxation, though it might also depend on legislation.

In the European Union there is a ban on the sale of combustion vehicles by 2035 (in the UK that date is five years earlier at 2030), but when that EU decision was signed in the early hours of 29 June 2022, it included a small-print clause tabled by Germany and supported by other EU member states, which obliges the European Commission to prepare a report by 2026 looking into alternative technologies such as plug-in hybrids and CO2-neutral fuels. 

An additional paragraph in the legislation preamble could provide a further exemption for e-fuels, which runs: “Following consultation with stakeholders, the Commission will make a proposal for registering after 2035 vehicles running exclusively on CO2 neutral fuels in conformity with EU law, outside the scope of the fleet standards, and in conformity with the Union’s climate neutrality objective.”

In reply to a question about these seemingly e-fuel friendly amendments, the Department for Transport told us there are no plans to alter UK legislation to suit as we have our own legislation and timetable, in spite of the fact in the past that the Government will shadow EU requirements on vehicle standards…

While there is considerable anti-e-fuel lobbying pressure from groups such as the non-government organisation Transport & Environment, which has issued several studies claiming e-fuels are neither as clean or will be as available as is claimed, perhaps one of the biggest issues with such synthetic fuels is the clean hydrogen on which they are based. 

While the UK Government seems reluctant to acknowledge the importance of hydrogen in transport for the future, Europe, North America and the Far East are gearing up for a big expansion of the fuel in applications such as heavy haulage, full payload vans, marine, rail and short-distance air travel, not to mention buffering duties for renewable energy generation to take the place of gas electricity generation. In such a future, e-fuels might be far down the list of priorities.