Future Fuels

Click on the bubbles to explore low-emission alternatives to Diesel

Liquified
Natural Gas

Liquefied natural gas (LNG) is natural gas that has been cooled to a liquid state (liquefied), at about -162°C, for shipping and storage.

The volume of natural gas in its liquid state is about 600 times smaller than its volume in its gaseous state in a natural gas pipeline.

LNG is transferred to a regasification plant where it is heated and returned to its gaseous state. The gas is then transported via pipelines to customers, providing energy for homes and industry.

  • Fully compatible with natural gas engines
  • Enables combustion of natural gas in places where pipeline gas is not available
  • Availability tied to port / LNG facilities and supply logistics
  • Cryogenic storage and transport is expensive, which can offset advantages

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Disadvantages

Flare gas

Flare gas is a byproduct of numerous industrial processes. Typically, it is emitted when unwanted or excess gases and liquids are released during normal or unplanned over-pressuring operation in industrial processes, such as oil-gas extraction, refineries, chemical plants, coal industry and landfills.

Instead of flaring these gases into the atmosphere, they can be stored and used as fuel for electricity generation.

  • Inexpensive - usually available at low or zero cost
  • Widely available and reliable
  • No significant engine modification needed
  • Presents monetisation opportunities to users
  • Gas treatment might be needed
  • Investment is needed to increase production and further reduce flaring

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Disadvantages

Biogas / Landfill gas

Biogas is created through the fermentation process of plants and manure, in which waste is digested by microbes to produce methane gas (biogas), where the waste can be converted into biofertiliser and the gas can be used as a natural gas alternative.

  • The technology to produce biogas is relatively cheap, and it can easily be deployed in domestic settings
  • Biogas can be used interchangeably with natural gas fuel
  • It has a zero-emissions production process
  • There are no new technologies to simplify the production process, making it inefficient and outdated
  • Impurities after refinement result in engine corrosion
  • Production not suitable for every location, relies on abundant supply of manure and crop materials

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Disadvantages

(Green) Hydrogen

Over 95% of the hydrogen used is currently derived from fossil fuel feedstocks through reforming, with the rest being produced using electrolysis.

If renewable energy is used to generate the power needed for the electrolysis process, green hydrogen can be produced.

Hydrogen fuel cells create electricity by combining hydrogen and oxygen atoms. The hydrogen reacts with oxygen across an electrochemical cell similar to that of a battery to produce electricity, water, and small amounts of heat.

  • It produces zero carbon emissions
  • Versatile and can be transformed into electricity and synthetic gas
  • There is already infrastructure available to support it, as it can travel through existing gas pipelines when up to 20% is mixed with natural gas
  • Expensive and complex to produce
  • Energy density remains a huge issue for transport and storage
  • Highly volatile and flammable

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Disadvantages

(Bio)-Methanol

Although methanol is generally produced by steam-reforming natural gas, it can also be used as a sustainable fuel when produced from biomass. Methanol produced in this way is known as bio-methanol.

Using bio-methanol as fuel can cut greenhouse gas emissions by around 200% compared with fossil fuels.

  • Transportation and storage are inexpensive due to the similarity with hydrocarbon fuels
  • It has a low risk of flammability, so is safer than gasoline
  • Cheap to produce relative to other alternative fuels
  • There is a lack of dedicated infrastructure - methanol production has declined significantly since the early 1990's
  • Corrosive and toxic
  • Miscible with water

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Disadvantages

Green Diesel /
Hydrotreated
vegetable oil (HVO)

Hydroprocessed esters and fatty acids (HEFA) are obtained by reacting fatty feedstocks, such as soybean oil and animal fats with hydrogen in a 2-step process.

The resulting product is distilled; the heavier fractions are diesel-like and called Hydrotreated Vegetable Oil (HVO) and the lighter fractions are kerosene-like and called Biokerosene or Biojet - these are sustainable aviation fuel alternatives.

  • Most advanced alternative to fossil diesel
  • An alternative to fossil diesel without the need to amend infrastructure or clean out existing stock
  • Stable product and remains usable in temperatures as low as -32°C
  • Around 10-15% more expensive than fossil diesel
  • Inconsistent quality, especially when palm oil is used
  • Weak supply chain

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Disadvantages

Powerfuels

Powerfuels, also referred to as e-fuels, are renewable electricity-based fuel sources. These include synthetic natural gas (SNG), liquified natural gas (LNG), Fischer-Tropsch diesel (FT/e-diesel), methanol or ammonia. Their production requires green hydrogen made from renewable energy.

  • Provide carbon-neutral solutions where energy requirements are high but hydrogen is unviable
  • Are drop-in alternatives and compatible with existing equipment
  • Can be used as energy storage for renewable power sources
  • Production at scale requires a low-cost source of green hydrogen
  • Currently expensive and require further investment to make them viable

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Disadvantages

Fatty Acid
Methyl Ester
(FAME) / Bio-diesel

Fatty feedstock, such as vegetable oil including oil from fast food restaurants and waste animal fat, is combined with methanol in the presence of a catalyst to produce a Fatty Acid Methyl Ester (FAME) biodiesel with glycerol as a byproduct.

When burnt with alcohol, FAME produces a methyl, ethyl or propyl ester.

  • Established supply chain
  • Biodegradable and low in toxicity
  • Carbon neutral
  • Can be blended with gasoline to reduce polluting emissions
  • Energy volume is much lower than petrol or gasoline
  • There is a possible need to modify vehicles to support ethanol fuel

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Disadvantages