Clearing up the Confusion on Low Carbon Fuels
Low-carbon fuels are an essential component of the energy transition mix required for Australia and the rest of the world to achieve Net Carbon Zero targets.
Low-carbon fuels are alternatives to fossil-derived fuels that still offer the benefits of high energy density and ease of transport. They are particularly applicable to reduce carbon in areas that are not easily addressed in the near term with hydrogen or electric options such as powering heavy vehicles and industrial equipment in remote locations and in aviation.
Low-carbon diesel forms part of a low-carbon economy solution and there has been a lack of understanding of the distinction between biodiesel and renewable diesel that we have seen as a barrier to the uptake of renewable diesel. In this article, we highlight the distinction between the two to demonstrate the importance of renewable fuel in our energy transition from fossil-derived diesel.
...there has been a lack of understanding of the distinction between biodiesel and renewable diesel that we have seen as a barrier to the uptake of renewable diesel.
This article compares and contrasts biodiesel and two types of renewable diesel: HVO, or hydrotreated vegetable oil, and renewable diesel derived from lignocellulosic biomass feedstock, utilising a high-temperature pyrolysis process and which Frontier Impact Group is developing under a branding called Renuleum. This article discusses the various feedstocks and technologies pathways to describe the differences between the two these various types of low-carbon diesel.
All Bio and Renewable, Clean and Sustainable
Biodiesel and renewable diesel are both classified as 'biofuels' because they are derived from biogenic sources – such as vegetable oils, animal fats, or woody residues from forestry, agriculture and other industries. All can be labeled 'renewable' because they are derived from renewable sources which can be replenished. All can be considered sustainable energy sources provided the feedstocks from which they are manufactured are sustainably sourced. The sourcing of sustainable feedstock is critical to the sector and this will be the focus of an article we plan to send out in the near future.
Biodiesel
Feedstock: Biodiesel is produced using a variety of 'oily' feedstocks, such as canola, soya bean, rapeseed, animal fats, and used cooking oil.
Process:
Extracting the oils from the feedstock
Treating the oil with an alcohol, such as methanol, in the presence of a catalyst, such as sodium hydroxide, which reacts to form glycerin and fatty acid methyl esters (FAME) – i.e. biodiesel.
Washing and drying the biodiesel to remove impurities.
Filtering the biodiesel
Blending the biodiesel
Testing to ensure it meets the relevant quality standards.
Physical properties: Similar but different to fossil-fuel-derived diesel.
History: Biodiesel has been produced in Australia since the late 1990s, with varying degrees of success in terms of commercialisation.
Use in Vehicles: Biodiesel must be blended and or the fuel system upgraded before it can be used in vehicles, generators, or engines.
Comparing Renewable Diesels: HVO vs Renuleum
Renewable Diesel is an emerging fuel that is 100% drop-in, i.e. can be used as a direct fuel replacement for fossil fuel-derived diesel in many vehicles and equipment applications including trucks and trains, tractors, and generators.
Feedstock:
HVO is produced from the same oily feedstocks as biodiesel – canola, soya bean, rapeseed, animal fats, and used cooking oil.
Renuleum is produced from lignocellulosic feedstock such as woody and agricultural residues.
Process:
HVO: Hydrotreating oils and fats using hydrogen and catalysts at high temperatures.
Renuleum: Pyrolysis (high-temperature application of heat in the absence of oxygen) of lignocellulosic biomass to thermally decompose the biomass to produce a synthesis gas (syngas), that is then condensed into renewable diesel (no catalyst required).
Physical properties: Almost identical to fossil-fuel-derived diesel with typically a slightly lower density due to a higher cetane rating which makes renewable diesel urn cleaner than fossil-fuel-derived diesel.
History: HVO has been sold for a few years in Europe as 'renewable diesel' but has not been sold in large quantities in Australia as yet.
Use in Vehicles: HVO and Renuleum renewable diesels can be used as a replacement for fossil fuel-derived diesel, without the need for blending or capital expenditure to modify vehicles and equipment.
The key benefit for renewable diesel is that it is a 100% replacement as opposed to biodiesel which typically can only be used as a blend. The ability to utilise a 100% drop in alternative will be crucial for those companies aiming to transition to net carbon zero. Whilst we believe there is much more sustainable feedstock available for renewable diesel production and particularly Renuleum, we believe both biodiesel and renewable diesel form an essential part of the mix required to transition to net carbon zero. It is imperative though that feedstock is sustainably sourced and that is key focus for Frontier Impact Group.
Sustainable Aviation Fuel
Both HVO and Renuleum can be upgraded to Sustainable Aviation Fuel (SAF) for use by airlines. Watch this space!
