As more and more industry players and government entities around the world propose, endorse, and enforce sales ban of Internal Combustion Engines (ICE), the big question to be asked is: what will become of the existing ICE vehicles and generators around the world? It is undeniable that the main issue surrounding ICE, more specifically compression ignition (CI) / diesel engines, is the harmful tailpipe emissions. It is evident that diesel engines emit exhaust gases containing soot, smoke, NOx and carbon emissions which contribute towards climate change. However, we believe that a blanket ban on engines would not make carbon emissions disappear overnight, and the fact remains that the ICE infrastructure would remain the status quo for a few decades, especially in heavy-duty trucks, off-road machinery, and generator sets all around the world. This begs for another bigger question: how can we reduce harmful emissions from diesel engines around the world in the here and now?

We attempt to answer both questions by introducing an alternative future that would transform transportation and energy, by using water-in-diesel emulsion fuel supplied in real time to diesel engines using an in-line mixer system incorporated in the fuel line system. We call this system Real-Time Non-Surfactant Fuel Supply System (RTES). The benefits of water-in-diesel fuel are well documented, with the main attractions being reductions in NOx and smoke emissions and improved fuel economy due to cleaner combustion. The main challenge for large-scale utilization of this fuel is the high cost of emulsifiers/surfactants to bind the water and oil particles together. Surfactants are important to ensure water-in-diesel emulsions are stable and homogeneous for a long period of time. By continuously mixing water and diesel in-line, we can circumvent this issue besides providing consistent water droplet sizes in the emulsion.

RTES works by mixing water and diesel in 2 stages: 1) injection of fine water droplets into diesel fuel flow and 2) mixing by mechanical agitation and static mixing. All these mixing regimes ensures an even and fine water droplets dispersion inside the diesel oil. Furthermore, a controller is used to maintain a constant water percentage throughout the system. We designed RTES to be modular, with emphasis on “plug-and-play” design so that it can be retrofitted into existing diesel engines. On top of that, it can be easily scaled up and down, accommodating a wide range of applications from small 2 kVA generators to modern common rail SUVs.

We aim to market this product in diesel engine generators for off-grid power generation. In the Asia pacific region, this market segment is worth 5.51 billion USD in 2021 (Fortune Business Insights, 2022). Moreover, as Malaysia and Indonesia are committed towards 30% biodiesel blends mandate, and moving towards higher blends, implementation of RTES would be beneficial in reducing fuel consumption and improve relatively high NOx emissions in diesel engines.