Auto part maker Tenneco, headquartered in Lake Forest, Illinois, USA, has partnered with academics and industry experts to explore synthetic fuels (e-fuels) in a collaborative effort known as the NAMOSYN project. The project will examine the technical possibilities and commercial feasibility of synthetic fuels, a near-term solution that could extend the market lifespan of the internal combustion engine (ICE) by minimising its carbon footprint, thus making it a viable option amidst the automotive industry’s green revolution.
Synthetic fuels for passenger vehicles, commercial trucks and marine applications may play an important role in achieving near-zero emissions mobility, by using renewable energy sources (e.g., solar or wind) to create a closed CO2 ‘well-to-wheel’ cycle. As a climate-neutral alternative to petroleum-based fuels, they also offer the potential for significantly reduced overall emissions, which Tenneco hopes will allow its Clean Air experts to better manage any remaining pollutants through the post-treatment process.
Synthetic fuels can be used in today’s gasoline and diesel engines, with only minor modifications required for most e-fuels, either alone or in blends with conventional fuels – this makes them suitable for both vehicles with traditional ICEs and hybrids. Additionally, the e-fuels can be made available to consumers by using the existing, well-developed fuel distribution and filling station infrastructure with only minor adjustments, making the technology even more appealing as a fast-to-market solution.
To minimise climate impacting emissions, synthetic fuels are, preferably, produced using electricity that is generated from carbon-neutral renewable sources. In the case of OME and DMC, synthetic fuels such as methanol, ethanol, MTG Fischer Tropsch Diesel, and others can be produced with hydrogen by electrolysis – also generated by using surplus fluctuations in renewable electricity – and carbon dioxide, which comes from industrial waste gasses or from the air. The next process step converts the syn gas to synthetic fuels. This method ensures that a closed CO2 cycle can be created, wherein the vehicle emits only as much CO2 as was originally extracted from the air to produce these synthetic fuels.
One of the advantages of synthetic fuels is that their composition can be developed specifically to meet the needs and different performance requirements of their applications. In order to achieve the highest possible efficiency (e.g., via so-called lean combustion), adjustments to engine control and hardware are necessary, depending on the engine type.
“It is widely acknowledged that solutions must be found to reduce a vehicle’s carbon footprint,” stated Steffen Hoppe, Director Global Technology for piston rings and cylinder liners at Tenneco’s Powertrain business group in Burscheid, Germany. “In addition to light vehicles, internal combustion engines are also popular in trucks, marine propulsion, construction equipment and agricultural machinery.”
“Regardless of the differing opinions when full electrification will be reached, any technology that we can adopt now that enables a significant reduction in CO2 emissions, or even CO2-neutral operation of the IC engine, will be an essential contributor to the timely achievement of climate targets,” he continued. “We are excited to be an active part in the development of this type of technology.”
In line with this goal is Tenneco’s involvement in the German-state-funded NAMOSYN project. From its Burscheid location, equipped with nineteen fully automated and monitored high-performance test cells, a team is actively investigating how innovative piston ring designs can be combined with synthetic fuels in order to develop mobility concepts with the lowest emissions, with an eventual target of zero.
The NAMOSYN project also intends to develop cost- and energy-efficient manufacturing processes for synthetic fuels and to test them in internal combustion engines. In the diesel sector, this notably concerns the group of oxymethylene ethers (OME); for gasoline engines, dimethyl carbonate (DMC) and methyl formate (MeFo). In parallel, a wide range of different material configurations are tested to determine the optimum synthesis and composition over/across the entire process chain.
Initial results of the current research are said to be promising. “By using synthetic fuels in internal combustion engines, we have been able to demonstrate a reduction of 50% or more in all nitrogen oxide, carbon monoxide and particle emissions,” commented Bartosch Gadomski, Senior Test Engineer and Project Manager NAMOSYN at Tenneco. “In order to actively support the timely market introduction of synthetic fuels as far as possible, we also test mixtures or blends of conventional fuels and e-fuels under real conditions on our engine test benches.”
In the final step, these test units are installed in test vehicles and examined for driving behaviour and emissions. In addition, the compatibility of the e-fuels with the existing infrastructure for fuels, such as tank trucks or filling station systems, is evaluated, and solutions based on any new requirements are developed.
Hoppe concluded, “The development of new vehicles with ICE powertrains must pursue the goal that these drives will be climate-neutral. We need synthetic fuels and hydrogen from sustainable energy sources in order to achieve the climate targets for future cars and trucks, but also for the millions of existing vehicles powered by an internal combustion engine.”