BMW, ZF supplier aims to convert diesels into hydrogen-fueled powerplants

Guido Dumarey is an outspoken Belgian engineer who in 1986 created Punch Group, a family-owned collection of businesses and investments in Europe with annual revenue of more than 500 million euros.

Much of that revenue comes from Punch Group's automotive arm, which supplies powertrain parts and engineering services.

Dumarey, who is CEO at Punch Group, specializes in buying what he calls “widows,” which are struggling businesses that the owners are willing to sell at deep discounts to save jobs. The widows are restructured and many of them are sold, often as part of an initial public offering.

Two key parts of Punch Group’s existing portfolio are discarded General Motors units in Europe: a transmission plant in Strasbourg, France, and a propulsion engineering center in Turin.

The Strasbourg plant, bought in 2012 and renamed Punch Powerglide, received 250 million euros in funding to expand its products and production.

Today the factory supplies six- and eight-speed automatic transmissions to BMW, ZF Friedrichshafen as well as Chinese, Russian and Indian automakers.

Punch Group says that restructuring saved 1,000 direct and 3,000 indirect jobs in Strasbourg.

After six years of trying, Punch in 2020 convinced GM to sell its Turin engineering complex, which had served as U.S. automaker’s global center of competence for diesels since 2005.

Purchasing the business, which was created by GM in 2005 after it separated from Fiat Auto, gave Punch Group access to more than 700 engineers and technicians who work at the Turin Polytechnic Citadel.

Dumarey plans to use all that knowledge and experience to transform diesels into CO2-free, hydrogen-fuel powerplants. He explained how in an interview with Automotive News Europe Associate Publisher and Editor Luca Ciferri.

Punch plans to begin producing hydrogen-fueled powerplant from diesel engines by 2024. What is the rationale?

It is relatively simple: Europe and China are mandating zero emissions for any type of transportation. Battery-powered vehicles are one option, but not the only option, particularly for heavy trucks and light commercial vehicles. The most relevant figure for those vehicles is the available payload. But to increase range you need more batteries, which adds weight and reduces the payload. Therefore, we think that converting diesel engines to burn hydrogen provides a very efficient way to offer CO2-free mobility that is beneficial both technically and socially.

Why socially?

The automotive industry, particularly in Europe, has made massive investments in diesel technology, ranging from the engines to the injection and control systems and more. All these investments – and most of the jobs connected to diesels – are at risk of extinction if we will go to battery-power only.

What are the biggest technical challenges in converting a diesel to burn hydrogen?

Hydrogen burns seven times faster than diesel, so you need to decrease the temperature in the combustion chamber. Water injection is a proven technology to do this, but a negative side effect is that this creates corrosion. Lubrication is another potential issue for an engine that tends to be very dry, so spray lubrication is the only solution. The engine itself only needs minor changes to the cylinder head. The injection and control systems also need to be reworked to handle hydrogen.

Is it more difficult to convert a gasoline engine into a hydrogen-burning powertrain?

Not really. The main issue is durability. Modern diesels are designed to last for 350,000 km while gasoline engines designed to last for about 250,000 km.

Punch Group plans to start producing hydrogen-fueled engines by 2024. What will be in the portfolio?

We are working on CO2-free solutions ranging in power from 80 kilowatt hours to 400 kWh (109 to 544 hp). At the top of the range, we are currently testing an evolution of the GM Duramax 6.6-liter V-8. (This unit was designed by the Turin center under GM. Punch has the rights to sell the hydrogen-powered variant of the engine worldwide, while the diesel version can be sold everywhere except the U.S.) Then we are working on a 500 cc combustion chamber that can accommodate several displacements, from  a 3.0-liter V-6 to a 2.0-liter I-4. We also have the ability to make a 1.5-liter three-cylinder, but it is not on our near-term plans.

Looking at Punch Group’s history, are you already targeting any potential diesel engine factories to add?

I cannot say anything specific, but you can easily imagine there will soon be plenty of “widow” diesel engine plants around Europe.

Why do you expect a top down spread of hydrogen-powered engines?

Mainly because of the limitation of the recharging infrastructure. By 2023-24, Europe should start to have in place a significant number of hydrogen stations on major highways. (The EU Green Deal proposes there should be hydrogen refueling stations every 150 km on Trans-European Transport Network corridors by 2030.) That will be enough for heavy trucks. Light commercial vehicles up to the size of a Ford Transit will follow.

And what about passenger cars?

Here the challenge is more on the package than on the technology. A car needs a tank capable of storing about 4 kg of hydrogen. While the weight of the tank is a fraction of a battery pack – about 50 kg versus several hundred kilograms for the batteries – the tank requires a space of approximately 100 liters. This is a significant packaging challenge if you want to house the tank in the trunk of a sedan. It’s even more problematic with hatchbacks. For passenger cars, we think the more promising solution is an electrified flywheel, which we call a Flybrid.

What is a Flybrid?

It is a mechanical flywheel that runs at speeds up to 42,000 rpm and gives kinetic energy recuperated while braking back to the wheels. The kinetic energy is used to reduce the engine load at start and when accelerating. We have a second application where a generator is connected to the flywheel to charge a small battery. Here the stored energy is given back to the vehicle using a motor inserted in the transmission, similar to what happens with full hybrids. We have been testing this solution in some taxis in London, where we have seen fuel consumption savings of about 34 percent. We have also tested the Flybrid on a Jaguar XF diesel, delivering a 22 percent reduction in fuel consumption.

You have had a very successful career in automotive, any regrets about deals that did not get done?

My failed attempt to buy GM’s Holden plant in Adelaide, Australia. That plant produced vehicles on a very good rear-wheel-drive platform, Omega. I moved into the powertrain sector because the best platform for multiple applications is rear-wheel drive and I lost it. But it is what it is. (GM and Punch ended negotiations for the plant in February 2016, with operations halting in October 2017. A total of 7.6 million cars were built at the factory over 69 years).