SYNTHETIC FUEL Flashcards
RAF FIRST FLIGHT 100% SYNTHETIC FUEL
The fuel is manufactured by:
- extracting hydrogen from water and
- carbon from atmospheric carbon dioxide
Using energy generated from renewable sources like wind or solar, these are combined to create the synthetic fuel
What is synthetic fuel?
Synthetic fuels are made using renewable power (wind, solar) and efficient industrial processes (carbon capture, electrolysis, thermal reactions) and should not be confused with biofuels or fuels made from waste.
Using an industrial non-biological process is controlled, efficient, reliable, secure and scalable.
Manufacture can be co-located in territory – self-contained energy generation without dependence on any foreign supply of raw materials.
The process of manufacture and consumption is fully circular – creating an industrial carbon cycle which can continue indefinitely in balance with the environment, just as the biological carbon cycle has done for billions of years
UNIQUE BENEFITS OF ORGANIC CHEMICALS
A wide range of energy applications exist which are neither suitable for electrification (as first choice) nor hydrogen (as second choice).
These applications are typically in the transport sector, in any vehicles for which the weight and/or the size of the mobile energy store is a performance-limiting parameter.
This will also be a function of the quantum of energy required (for range and/or endurance).
The energy density of batteries is typically:
- 50 times lower (mass basis) and
- 15 times lower (volume basis)
than typical liquid fossil fuels (hydrocarbons), net of the differing efficiencies of electrical and combustion motors.
The energy density of hydrogen (once contained in a tank) is better than a battery but still typically:
- 4 times lower (mass basis) and
- 5 times lower (volume basis) than fossil fuels.
These factors leave a performance gap which remains critical for a huge range of common and vital assets to the industrial system – such as aeroplanes, any military vehicle, helicopters, fast boats and high-performance cars.
Perhaps surprisingly, agricultural machinery lies within this list: a combine harvester is weight-limited (soil compaction) and endurance-limited (intense working when active) and is itself arguably the single most important machine to have enabled humankind’s release from a fully agrarian society.
For all of these machines, high density energy stores – such as those currently provided by gasoline, kerosene and diesel - are not optional.
These vehicles will simply not function with the weight and volume penalties presented by battery or hydrogen tanks of equivalent energy.
At the same time, the mass and volume deficiencies of electrical and hydrogen energy stores will not be closed by technical development – these gaps are a function of fundamental chemical and electro-chemical constraints.
It is interesting to revisit biology at this point. Not by accident, nature has also chosen hydrocarbons (organic chemicals) for the distribution and storage of energy in the form of oil, fat, sugar and starch.
These are nature’s equivalent of gasoline, kerosene and diesel fuels in industrial systems.
The chemical step necessary is the addition of carbon to the hydrogen molecule – converting a high energy gas into a dense and portable liquid form.
INDUSTRIAL BIOENERGY
Humans have an affinity with nature – plants and animals – and so despite the accessories of modern life there is an ever-present desire to “return to nature”.
So biology is a popular destination to seek replacements for fossil fuels.
A huge range of biofuels have been developed over several decades including bioethanol and biodiesel.
First Generation biofuels use directly cultivated products such as cane and maize (converting sugar and starch respectively).
Developing concerns over land competition and displacement of food production have created pressure to migrate to Second Generation biofuels which use agricultural waste as feedstock (converting, more typically, cellulose).
The macro-chemistry for this bioenergy model appears attractive and fully sustainable.
However, the cultivation and conversion processes are intensive in energy overhead and water consumption. Plants are not efficient solar energy converters relative to industrial machines (a typical field crop is 22 times less efficient than a solar panel).
Many biofuels are marginal if not negative in net-energy after cultivation and processing.
Biodiversity is a risk (disease, for example) in the event that biofuels are adopted at scale, and, being a partly biological, non-industrial process (and therefore not fully controlled) the security of supply is poor.
Land competition is the killer-blow to the adoption of bioenergy as a source for the required liquid hydrocarbon fuels as it will require an unrealistic fertile land mass and pressure for further massive deforestation.
Indeed, it is wholly unreasonable to expect biology to now compensate for the enormous energy demands of the modern industrial system when nature is already under catastrophic pressure from that same system.
Whilst there are some special cases where bioenergy has positive environmental benefits, it must remain a niche solution within a future sustainable energy model.
FUELS FROM WASTE
Many organic products including hydrocarbon fuels can be produced from waste.
These fit broadly into two categories:
- biological waste and
- petrochemical waste.
Biological waste includes a wide range of source material – ranging from agricultural by-products (such as straw), waste biomass (such as forest residues, construction timber) and municipal waste (such as food, oil).
There is great merit in taking further benefit from energy already captured in organic material provided the processing energy (especially fossil-based energy) and other resource consumption (especially water) are appropriately accounted.
Side benefit exists in any reductions to alternative waste disposal impacts such as landfill.
Products derived from biological waste are in effect a specialised sub-set of industrial bioenergy and suffer from the same limitations especially in respect to scale.
Petrochemical waste includes plastics waste and non-biological industrial waste.
The primary merit in recycling these wastes comes from the benefit of consuming existing or avoiding further contamination to the environment (such as ocean plastics, landfill).
From a global warming perspective, fuel products derived from petrochemical waste which was originally manufactured from fossil-based petroleum precursors are simply a deferred version of conventional fossil fuels with identical macro-chemistry including equivalent carbon-dioxide emissions.
In the absence of any associated carbon capture process, these products remain classified within the unsustainable fossil fuel energy model.
As will be discussed later, fuel products derived from petrochemical waste which was not manufactured from fossil-based petroleum precursors, but manufactured from synthetic petroleum precursors (products of petrosynthesis) may legitimately be combusted and are classified within the sustainable and circular petrosynthesis energy model.
In all of the above categories, security and quality of supply present additional challenges to direct fuel production (biofuel, fossil fuel or synthetic fuel respectively), since the source waste material is, by definition, a by-product of upstream activity that is dictated by others in composition and quantity.
