Starting from a deep concern over the loud noise of diesel engines—long associated with black smoke and the smell of fuel—the research team from Universitas Sumatera Utara sought to overturn that stigma. In reality, diesel engines are not merely wasteful and dirty machines, but an opportunity to transform them into efficient and clean energy sources. Through research that combines dual-fuel strategies and nano-particles, two USU researchers, Tulus Burhanuddin Sitorus and Taufiq Bin Nur from the Mechanical Engineering Study Program, Faculty of Engineering USU, succeeded in opening a new pathway for the future of diesel engines in the era of renewable energy.

 

This research, which has been internationally published in the journal Applied Energy, emphasizes that diesel engines do not have to be enemies of the environment. With an integrative approach rarely used before, they combined three major fields of study: dual-fuel strategies, the use of nano-additives, and advanced combustion technology. The results obtained were not only improvements in efficiency, but also a real potential to reduce emissions without the need to replace the entire existing engine infrastructure.

 

“This is a solution that is not only visionary, but also realistic for developing countries like Indonesia. All this time, many global studies have focused on a single alternative fuel, like biodiesel, hydrogen, or ammonia. However, we see that the future of energy actually lies in a smart combination,” said Tulus enthusiastically.

 

This study found that a mixture of ammonia and hydrogen can increase the engine’s thermal efficiency by up to 42 percent compared to pure diesel. This mixture produces a more stable combustion process and nearly zero carbon dioxide emissions. Meanwhile, using biodiesel with an elliptical injector design can increase efficiency by 15%, and methanol in a dual-fuel system can also deliver an increase of up to 12%.

 

“However, we also cannot deny that every fuel has its dark side. Biodiesel does reduce carbon monoxide and particulate emissions, but it actually increases nitrogen oxides (NOx) due to higher combustion temperatures,” explained Taufiq.

 

Alcohols such as ethanol and methanol do have cooling effects and more homogeneous combustion, but they are prone to ignition delay. Hydrogen is almost perfect in terms of emissions, but it is very reactive and difficult to control. And here lies the innovation of the USU researchers: instead of choosing one ‘ideal’ fuel, they combine multiple fuels and regulate how they work together efficiently.

 

Another secret lies in nano-sized particles. The team’s research found that nano-additives such as aluminum oxide (Al₂O₃) and cerium oxide (CeO₂) act as micro-catalysts that improve fuel atomization. Imagine finer fuel droplets that burn more completely and produce more energy without leaving toxic gas residues. As a result, carbon monoxide and hydrocarbon emissions can be reduced by more than 20%, while thermal efficiency rises significantly. With such a small addition, the resulting impact is enormous—an illustration of how small innovations can have major consequences for the future of energy.

 

“What makes this work different from similar studies is the way they bring together separate findings into one integrated conceptual framework. Sitorus and Nur did not stop at laboratory experiments, but built a cross-fuel comparison framework that maps the relationships between chemical structure, combustion behavior, and resulting emissions,” added Tulus.

 

This framework becomes a kind of grand map that other scientists can use to develop low-emission fuel systems in various countries. They not only conducted research, but also charted a new direction for global green energy studies.

 

More than just scientific results, this research carries a strong message that innovations from Indonesian universities can stand on equal footing on the world stage. It highlights that no single fuel is perfect, but a smart combination can be the bridge to a clean energy future. This idea is highly relevant for Indonesia, a country still heavily dependent on diesel engines for maritime transport, agriculture, and logistics. With this approach, existing engines do not need to be replaced entirely; instead, they can simply be adapted with dual-fuel systems and nano-additives to become more efficient and environmentally friendly.

 

The future envisioned by this research feels tangible and close to everyday experience. Imagine logistics trucks that no longer emit black smoke, fishing boats operating with biodiesel-hydrogen blends, and factories in remote areas using smart combustion systems without increasing pollution. All of this is possible if USU’s laboratory innovations continue to be developed toward industrial application.

 

This research shows how science can become a real solution to energy and environmental challenges. In the hands of young Indonesian researchers, diesel engines are no longer symbols of the past but vehicles toward a cleaner future. When nano-particles unite with dual-fuel strategies, what emerges is not only efficiency, but also hope. Hope that technology does not always need to come from abroad, because sometimes the greatest innovations grow from universities in our own homeland.