Diesel – Super-fuel? #OISF

The Orkney International Science Festival

by Mike Robertson

At the 2023 Orkney International Science Festival (OISF) Neil Kermode OBE spoke about his personal view of the next 20 years in energy renewables.  As someone who has spent his career promoting sustainable renewable energy, I was surprised to hear him extol the virtues of diesel as a fuel.  This is how it goes…

Our transition to net-zero must consider our modern lifestyle.   Fight against that and we will fail.  But that lifestyle includes things like air travel which is known to be a significant contributor to climate change. 

When looking at the fuels we need to maintain our lifestyle, the key factor is how much energy a fuel contains alongside its volume and weight.  For a lorry or bus the weight is less important than the volume but in a car it’s mostly the other way round.  For an airplane both weight and volume are important.   In this slide from Neil’s presentation, he plots the weight and volume against energy on a chart.

As you can see diesel sits at a sweet spot for weight and volume which explains why it is such popular fuel.  (Jet fuel, kerosene, for aircraft, although not shown, sits between Petrol and Diesel.)  Some of the lighter fuels like hydrogen initially seem attractive but, as the arrows on the chart show, when you include the additional equipment needed to store and handle them, they are not so good.  The problem is that our present diesel and kerosene are both fossil fuels which contribute hugely to climate change. Neil argued that what we need is non-fossil hydrocarbons.

To solve this problem, Pete Oswald’s* company iGTL & Zero Petroleum developed a process to produce synthetic gasoline.    His process combined hydrogen with carbon monoxide to produce gasoline and to prove its merit the RAF used this gasoline made from Orkney hydrogen for their first fully synthetic fuelled flight.

Of course, this fuel is still a hydrocarbon but if the fuel is made from carbon extracted from the atmosphere it is not based on fossil carbon. It is at least net-zero.

It is of course more expensive to produce than fossil-based diesel, but in a world where we cannot afford the old alternative there will be a need for these e-fuels. However, since Orkney already produces far more renewable energy than it needs, this might be the best way to export that surplus.

*Sadly, Pete Oswald died recently and will be greatly missed by all who knew him in OREF and beyond.

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