Nano-engineered crystals offer an alternative to metallic particles in fuels

The use of nano-engineered crystals instead of metallic particles in fuels could could open the door to the next generation of transportation fuels

Metallic particulates have long been known to improve the combustion qualities of standard fuels such as petrol and diesel, but vehicle manufacturers prohibit their use over concerns their long term use could be detrimental to engines.

Fuel additives and the history of destroyed machinery

This dates back to the 1973 oil crisis, where many Western countries suffered from severe fuel shortages resulting in vehicle owners resorting to desperate measures to keep their vehicles running. All sorts of fuel additives were used in an attempt to compensate for fuel shortages and many of these solutions damaged engines beyond repair. Swamped with a deluge of engine warranty claims, engine manufacturers introduced new conditions to their warranties, prohibiting a wide range of fuel additives, one of which was metallic particles.

These events also saw the introduction of the world’s first fuel economy and emission standard, which was passed by the US Congress in 1975. This provided the basis for the standardisation of fuel quality, which was designated as ASTM D975 for diesel fuels. The ASTM D975 standards have continually been subject to improvements over the years and they currently stand at their 18^th revision ~ ASTM D975-18a.

In Europe a more stringent fuel quality standard was introduced by the EU in 1993, known as EN590. This too has undergone several updates and is currently in its 6^th revision referred to as EN590 2014, with a new standard being planned with the introduction of Euro 7 engines in the coming years.

The combination of fuel economy and emission standards with fuel quality standards provides engine manufacturers and fuel producers a basis to work independently of each other, but ensures their products compliment each other. Advancements in fuel quality have progressed over the decades in line with the improvements in engine design, both of which have a common goal – better fuel efficiency and reduced emissions.

The problem of “incomplete combustion”

However, irrespective of improvements in engine design, all internal engines suffer from a physical limitation; this limitation is referred to as “incomplete combustion”, which means there is never enough oxygen to burn all of the fuel during the engine combustion process. The unburned or partially burned fuel that remains when the oxygen depletes is what we all know as “emissions”. These are a combination of solid particles such as hydrocarbon particles (PM 2.5) and gases such as carbon dioxide, carbon monoxide and nitrous oxides.

Creating additional oxygen during the combustion process would convert more fuel to energy, improving fuel efficiency thus reducing the leftovers or waste, which forms the bulk of what makes up emissions.

For many decades zinc oxide has been proven to improve fuel efficiency and reduce emissions. In most cases the limit of fuel efficiency improvements have been around 5%, due to a balance required between particles being small enough to pass through fuel filters and particles being large enough to survive long enough during the combustion process to provide a catalytic surface that creates additional oxygen.

So why is zinc oxide not being used?

However, nobody can benefit from this 5% improvement in fuel efficiency because zinc oxide, even though it is a mineral compound, is considered by engine manufacturers as a metallic and therefore banned from fuel as it is also proven to clog fuel injectors, which reduces fuel efficiency over the long term and rendered useless in terms of fuel efficiency improvements; until now.

Advancements in nano engineering and sonochemistry have resulted in a breakthrough that provides the means to produce super efficient, super low emission next generation fuels, which will dramatically reduce demand for fossil fuels during our transition away from them.

A team of scientists in the USA, each considered leaders of their respective fields of expertise, have combined their knowledge of fossil fuels, nano engineering, sonochemistry and material science to arrive at a solution that meets both the fuel certification and engine manufacturer’s standards.

What is sonication and how does it work?

Sonication is the act of applying sound to matter to agitate particles, with a variety of outcomes possible. To explain, all bodies of solid matter have their own resonant frequency and directing this frequency at said solid matter can agitate and break up or manipulate it. It is simply a matter of directing the correct frequency at the correct strength, for the correct period of time, under the correct conditions. Admittedly there are a lot of variables, which means there’s almost an infinite number of possible combinations needed to determine the resonant frequency of any given body of solid matter, but in theory, cancer cells in the human body could be destroyed using sound, much in the way kidney stones can be.

To describe their solution in the simplest terms, crystals are formed by condensing a gas, which are then cut into perfect spheres 20 nanometers in diameter using sound waves. For reference, there are 10 million nanometers in 1cm, so a 20 nanometer sphere is not visible to the human eye.  These tiny particles cannot be added directly to fuels, so they use widely available fuel additives used to clean fuel injectors and improve combustion efficiency, to act as a carrier.

This product is added to fuels in tiny quantities (1 part nanoparticles, 3,200,000 parts fuel) and the results are astonishing. Large scale testing has taken place all around the world, including power stations, trains, trucks, buses, cars, tractors, mowers, ships, generators and heavy machinery and in every case the improvement in fuel efficiency has exceeded 15%, which is groundbreaking in itself.

What could this mean for the future?

With such significant improvements in fuel efficiency, the resultant savings in outgoing fuel costs for fleet operators far exceed the cost of the product and with such a large drop in fuel consumption comes a significant reduction in emissions too, with nitrous oxides being reduced by around 85%, PM 2.5 reduced by 60% and CO2 reduces in line with fuel efficiency improvements. For context, 200 buses in central London used the product for 6 months and improved their fuel efficiency by 26%, which translates into a £9 million annual saving across their fleet of 1,600 buses.

On speaking with the commercial operation heading up the roll out of this product in Europe, their spokesperson confirmed that whilst COVID-19 has severally hit their progress, they are currently working with some of the worlds largest CO2 emitters, national governments and fuel producers and fully expect a large scale roll out on a global scale, once the COVID-19 crisis has passed.

Nano science is solving many previously unsolvable problems and this breakthrough could play a significant role in our attempts to achieve the UK’s net zero 2050 targets.