Deutsche Bahn, the Anglo-Australian Rio Tinto mining corporation, and the Golden Gate Ferry commuter service all have one interesting thing in common – they tank their vessels and vehicles with HVO, the clean and sustainable diesel fuel substitute. Numerous data centers are also powered by HVO, and snow groomers in Sweden that run on it are virtually climate-neutral.
Hydrotreated Vegetable Oil or HVO for short, is one of the sustainable paraffinic fuels regulated by the European EN 15940 and US ASTM D975 fuel standards. On balance, EVO lowers CO2 emissions by up to 90%. This is because, when combusted in the engine, EVO releases only CO2 – the gas which will already have been extracted from the atmosphere during the growth of the plants used in EVO manufacture. The remaining greenhouse gas emissions can be accounted for by production processes and raw material and fuel transport, meaning they arise in the upstream chain.
Benefits of HVO
- HVO is already available to buy.
- As HVO is a drop-in fuel, no adjustments are necessary for most diesel engines that are approved for HVO use. It is advisable however, to check elastomer seals regularly in the first four weeks following a switchover to HVO.
- The storage stability of pure HVO is substantially higher than that of pure Fatty Acid Methyl Ester (FAME) biodiesel, or HVO / FAME mixtures, and even fossil diesel fuel B7. That makes HVO particularly attractive to operators of standby power systems.
- Our tests have confirmed that there are usually no differences in the released mtu common rail engines in terms of their maximum power, load acceptance and fuel consumption - regardless of whether they are fuelled with HVO or diesel.
- Depending on the fuel manufacturing process, CO2 emissions fall by up to 90%. Particulate emissions fall by over 40%. Nitrogen oxide emissions are up to 8% lower.
HVO: The fuel made from plant waste
HVO is mainly produced from waste based on vegetable and animal fats and vegetable oil. Through the induction of a catalytic reaction and the addition of hydrogen, that waste is transformed into hydrocarbons, which exhibit a high oxidation stability. In other words, fats and vegetable oils are modified to assume the characteristics of diesel fuel, which they can either be added to or fully replace. “With its potential for sustainable business, HVO is pre-destined for use in the circular economy. Now we can use raw materials even more efficiently and process vegetable waste to manufacture sustainable fuel,” said Michael Stipa, Vice President Stationary Strategy, Business Development and Product Management at the Rolls-Royce Business Unit Power Systems.
The best news about HVO: it's already on the market. Even today, mtu engine operation can be almost CO2-neutral
Why does HVO make diesel engines almost climate-neutral?
When diesel or HVO is burned, CO2 goes into the atmosphere.
Regardless of whether the combustion engine burns HVO or diesel - CO2 is released into the atmosphere.
Plants bind CO2 from the atmosphere via photosynthesis as they grow.
Vegetable waste is used in the production of HVO. Therefore, the carbon footprint of biofuels like HVO is much lower than that of fossil fuels.
That the changeover to HVO can be made seamlessly has already been demonstrated by Rolls-Royce customers from all over the world: In 2022, Deutsche Bahn tanked its goods locomotives with over half a million liters of HVO and will be increasing that to 10 million liters in 2023. Jörg Schneider, Head of Climate Protection and Energy at DB Cargo even calls the fuel 'engine-friendly'. At its mine in Boron, California, in the US, mining giant Rio Tinto completely switched its heavy machinery operation from fossil diesel to HVO, making the open pit mine the first in the world to have cleared that milestone. Its evaluation so far has been entirely positive, with the performance and reliability of the engines comparable to those running on diesel fuel. Staying in the US, the Golden Gate Ferry service in San Francisco has been using HVO in its vessels since 2019 – clocking up well over 120,000 operating hours. Michael Hoffman, deputy General Director of the Golden Gate Bridge, Highway & Transportation District, wants to see the trend continue: “There is much less smoke visible in the ferry terminal since we made the switch from conventional diesel to HVO,” he enthused. Finally, AVK, the biggest supplier of standby power solutions to data centers in Great Britain, recently declared HVO to be its preferred fuel.
"Thanks to HVO, you can now mention internal combustion engines and sustainability in the same breath. With their physical characteristics such as power density, our internal combustion engines shall continue to be the solution that our customers in the off-road segment need and can rely on. And when you run these engines on HVO, they're virtually climate-neutral, with no need for significant investments."
Partnership with Neste
To facilitate the introduction of HVO and give Rolls-Royce Power Systems customers better access to this sustainable fuel, Rolls-Royce has forged a partnership with Neste – the Finnish fuel manufacturer who developed its own fuel brand under the name MY Renewable Diesel and is the world's leading renewable diesel manufacturer.
Differences between HVO and biodiesel
Although both FAME and HVO can be made from biomass organic matter and are therefore renewable and intended to replace fossil fuels, they exhibit clear differences:
- Chemically speaking, biodiesel is a Fatty Acid Methyl Ester (FAME) obtained through the transesterification of vegetable oil using methanol. The properties and quality of FAME biodiesel strongly depend on the raw materials used. HVO on the other hand is obtained in a hydro-treating process without the use of oxygen. The result is consistent quality, irrespective of raw materials.
- In its chemical composition, HVO is similar to fossil diesel fuel. That makes it suitable for direct use in all diesel engines, either in pure form or mixed with fossil diesel fuel. Biodiesel on the other hand is different in composition and if it is to be used in a diesel engine without making modifications, it can only be mixed with the fossil diesel fuel.
- Compared to FAME, HVO can be stored over longer periods without any risk of its properties changing. Since it does not absorb water, the quality of HVO is not compromised in any way as long as it is correctly handled and stored.
- Unlike biodiesel, the properties of HVO likewise remain unaffected by extremely low temperatures.
- Diesel engines running on HVO generate considerably lower nitrogen oxide emissions than with FAME.
- Unlike FAME, when HVO is used, the lubricating oil does not need to be regularly checked and adjusted in addition to existing maintenance.