Transport fuels and the future – biofuels and gases
The determination by Governments throughout the world to tackle man-made climate change means that transport fuels are constantly evolving. The aim is for a significant fall in greenhouse gas (GHG) emissions, including CO2, from vehicles. This is being implemented through the UN’s COP 21 / Paris Treaty which was ratified by the UK in 2016, and by the EU’s Renewable Energy Directive; Renewable Transport Fuel Obligation; and Fuels Quality Directive.
Between 1996 and 2015 changes in car engine design reduced CO2 emissions by 23% – so progress has already been made on this. However, with increased awareness of the health dangers from vehicle emissions in urban areas, it is likely that there will be a sustained attempt to de-carbonise fuels before 2050.
Already the EU CEN Standard allows the biofuel content of petrol to be a maximum of 5% ethanol (or E5 to standard EN 15376). In diesel up to 7% biodiesel (B7 usually the FAME product to EN 14214) is permitted. These levels have been agreed because they do not impact on the manufacturers’ vehicle warranties. A move to 10% biofuel content is under consideration.
The longer term alternatives to transport fossil fuels are:
- Advanced biofuels: these can be formed from biomass via the lignocellulosic process; by the gasification of woody wastes and straw using the Fischer-Tropsch process, or from photosynthesising algae.
- Compressed Natural Gas – methane (CNG): Already Liquified Propane Gas (LPG) and Liquified Natural Gas (LNG) are available and have been used successfully in engines, so use of CNG is possible. New fuel storage facilities are needed on forecourts and also more robust on-board fuel tanks.
- Hydrogen fuel cells: The use of hydrogen in fuel cells to produce an electric current is being researched although there are issues to be resolved about the storage of hydrogen and the weight of the fuel cells in vehicles.
- Hydrogen fuel: Trials in the safe use of hydrogen fuelled vehicles are underway.
Transport fuels and the future – electric vehicles
The move towards electric powered vehicles is already underway. Cars, buses and lorries with hybrid electric / conventional engines are on the market and perform well. Now that battery technology has advanced, battery only vehicles are becoming available using the TESLA battery. It is likely that the problems associated with early electric vehicles such as their limited range, long charging time, greater vehicle weight and size and low acceleration, will be resolved.
When most of the electricity from power stations is fossil-free, and most vehicles are powered by electricity we will be able to achieve near-zero GHG emissions from transport. However a large number of electric charging points will be required – so there will remain a role for “charging forecourts” in this scenario.