There is a great desire for drive technologies that are as sustainable as possible, but agricultural machinery regularly has to perform hard work in the fields: during harvesting, they are in use for entire days, and when ploughing, they are operated at full load. For this reason, there is no way around liquid energy sources in the foreseeable future, especially for heavy commercial vehicle drives, due to their high energy density. At the same time, the pressure to reduce CO₂ emissions is high.
The need to reduce greenhouse gas emissions is leading to the increased use of alternative fuels worldwide, which are not obtained from fossil raw materials but from renewable or synthetic sources. These fuels are either used in their pure form or blended with fossil diesel.
In addition to traditional biofuels (FAME), paraffinic and synthetic variants such as HVO (hydrogenated vegetable oils), GTL (gas-to-liquid) or PtL (power-to-liquid, e-fuels) are increasingly coming into focus. These fuels are characterized by high purity, stability and compatibility with modern engines.
The challenges of alternative fuels
Alternative fuels offer many environmental benefits, but also pose physical and chemical challenges. Biofuels in particular, such as fatty acid methyl esters (FAME), are susceptible to ageing processes that can cause problems such as corrosion, filter blockages or the so-called "diesel plague".
The ageing of fuels, especially biofuels, leads to increased acidity levels and the formation of deposits that can affect the service life of filter systems and engines. In addition, the water absorption capacity of these fuels increases, which increases the risk of corrosion and microbial contamination.
Innovative filtration ensures operation even under extreme conditions
This is why Hengst addressed the challenges of alternative fuels at an early stage and developed innovative filtration solutions that ensure safe operation even under extreme conditions. With validated materials, modern testing approaches and application-oriented development, the company is supporting the switch to alternative fuels - and setting new standards in reliability and long-term function.
Hengst meets the challenges of ageing with a specially developed test methodology that tests the durability of filter materials under realistic conditions. Different realistic ageing scenarios are simulated to ensure the durability of the filter components.
The focus of the development strategy is not purely on initial filtration, but on lasting functional reliability over the entire life cycle. To this end, Hengst has developed special processes for the artificial pre-ageing of fuels with defined acid values. These make it possible to test filter materials under practical conditions - especially with heavily aged biofuel blends, which tend to form organic acids.
Fossil gasoline will have no long-term prospects.
Dr. Andreas Dworog
Group Director Technology Center Processes
The oil circuit also faces challenges
Not only the fuel system is affected by alternative fuels, the oil circuit also faces additional challenges. A key risk with alternative fuels such as PME (plant methyl ester) is water ingress, which is exacerbated by hygroscopic properties. If nitrogen oxide also enters the lubricating oil via blow-by gases, acidification can occur - a chemical process that jeopardizes both the protective effect of the oil and the durability of the filter materials. Hengst meets this challenge with special test methods for assessing oil ageing and material compatibility.
There are also new requirements for hydrogen combustion engines: A hydrogen concentration of just four percent in the crankcase creates an explosive mixture. Hengst has developed valve-controlled forced ventilation systems for this purpose, which not only increase operational safety, but also reduce water ingress into the oil. In addition, blow-by separation systems ensure effective separation of oil and water droplets to protect the charge air duct from deposits, pre-ignition and sooting.
The future of ICE fuels is diverse
While vehicle manufacturers are pursuing different decarbonization strategies, Hengst is already prepared for a wide range of standard-compliant and borderline fuels. The filter systems are designed for biofuel blends such as B7, B20 up to B100 as well as paraffinic and synthetic variants such as HVO, GTL or PtL. Ageing, material compatibility and differential pressure curves are systematically recorded and incorporated into the development process.
Even if methanol or e-methanol are not yet approved throughout Europe, Hengst is already providing prototypes for testing.
Joint development as a success factor
The large number of possible fuels and their regionally differentiated standardization require a high degree of flexibility in the design of filter systems. Close cooperation with OEMs, research institutes and standardization bodies is often crucial for the rapid and reliable implementation of new requirements.
Hengst sees itself not only as a supplier, but also as an active development partner. The technical expertise is bundled in the company's own Tech Center Filtration - from material selection to simulation and prototyping through to validation.
Conclusion
The requirements for fuel and Oil Filtration in the context of alternative drive systems are changing fundamentally. Hengst Filtration meets these challenges with sound know-how, modern test methods and a comprehensive understanding of the system. The company's filter systems are prepared for all currently foreseeable fuels and guarantee lasting functional reliability even under difficult operating conditions.
In this way, Hengst is making an important contribution to safeguarding new drive technologies - and to the sustainable decarbonization of the off-highway and transport sector.
