Liquid Biofuels

Biofuels i.e. fuels derived from biomass crops or by-products that are suitable for use in vehicle engines or heating systems.


In the original proposal from the European Commission for a directive on biofuels three principal categories of alternative fuels were identified:

  • Biofuels i.e. fuels derived from biomass crops or by-products that are suitable for use in vehicle engines or heating systems;
  • Natural gas, with future large-scale use likely to be based on purpose built cars;
  • Hydrogen, with natural gas or electrolysis being the most likely initial large scale production methods.

Biofuels and natural gas were considered as having the potential to achieve market levels of between 5% and 10% by 2020 with hydrogen, which requires significant development before it is widely used as a transport fuel, attaining a 5% level by the same date.

Biofuels can be considered as potential replacements or extenders for mineral fuels such as diesel or petrol. They can be sub-divided into a number of categories, the principal two being:

  • Vegetable oils / animal fats which can be used in unprocessed form or converted to biodiesel;
  • Bio-ethanol produced from the fermentation of organic materials such as sugar beet, cereals, etc.

Vegetable oils include oil from purpose grown oil seed crops (oil seed rape, camelina sativa, etc.). They also include waste vegetable oil (or recovered vegetable oil – RVO) such as waste cooking oil from the catering industry. Animal fats include tallow produced by the rendering industry.

Other biofuels include the following:

  • Biogas (principally composed of methane), which is collected at landfill sites or from anaerobic digestion systems, could be used in vehicles in compressed form.
  • Bio-methanol and dimethylether (DME), which are produced from biomass derived methane, offer limited attraction compared to alternatives.
  • Bio-oil produced from the pyrolysis of biomass materials continues to be the subject of extensive research, although commercial uptake is limited as yet.

Vegetable oil and bio-ethanol technologies are now well developed and have reached commercial acceptance in many countries. The use of vegetable oil or its derivative, biodiesel, as a transport fuel is established in Germany and Austria where production in 2001 was 350,000 tonnes and  31,400 tonnes respectively. Bio-ethanol is widely used as an oxygenate in petrol in the USA, where production levels have reached 1.4 billion gallons, or approximately 1.1% of US gasoline consumption. A derivative of bio-ethanol, ethyl tertiary butyl ether (ETBE), is similarly used in France, where 219,000 tonnes were produced in 2001.

Download Biofuels for Transport Factsheet

Bioehanol Production
Bioethanol is an alcohol mainly produced by fermentation of sugar- and starch-containing organic materials. Commercialisation of biofuels for transport could be in the form of neat or blend type (the latter being mixed with oil derived from fossil fuels).
Biodiesel Production

Rapeseed oil represents the main feedstock (84% of the raw material sources). Other raw materials include sunflower, soybean or used frying oil (waste vegetable oil). Technological progress has been made in the recent past to broaden the feedstock basis and to improve process technology through flexibility in processing multi-feedstocks. Biodiesel as a pure fuel is getting increasing acceptance from car manufacturers, and also heavy duty vehicles (e.g.: Germany).

Feedstock Supply Chain
Potential Irish liquid biofuel markets

To find a market, liquid biofuels would have to displace some of their fossil equivalents. Table 1 presents the consumption figures for transport fuels in Ireland in 2002 (DCENR, 2003). The diesel figures in the table include fuel use in trains, and in boats on inland waterways.

Table 1 - Transport fuel consumption in 2001 and estimated biofuel requirement to achieve 2% substitution level

Current Fuel Quantity (tonnes)
Current Fuel Quantity (toe)
Biofuel Substitution (tonnes)
Biofuel Substitution (toe)
Diesel (road, rail, inland navigation)1,832,2771,971,00044,14839,420
Petrol (road transport)1,513,7411,688,00052,92433,760

To achieve the 2% substitution target mentioned in the Biofuels Directive would require the inclusion of approximately 97,000 tonnes of biofuels in the transport fuels consumed in Ireland (Table 1).

Current Status in Ireland

Biofuels is one of the ways to address the challenges posed by the transport sector. In this context the options for Ireland in the near term (to 2010), based on proven technology are biodiesel and bioethanol. Pure plant oil (PPO) and biogas which are suitable for modified engines have a role to play but their potential is quite limited due to their incompatibility with standard engine design and fuel distribution infrastructure. Biodiesel on the other hand can be blended with diesel to a 5% level and used as a fuel in any diesel engine under normal manufacturer’s warranty. Similarly bioethanol can be blended with petrol at a 5% level and used in any petrol engine. The use of bioethanol is being expanded further with the introduction of flexible fuel vehicles (FFV’s) which are capable of operating on an 85% ethanol:petrol blend.

The higher production costs of biofuels compared to diesel and petrol mean that government action is necessary to realise the development of the former. Under the “Pilot Excise Relief Programme” in 2005 the Government granted full excise relief to 8 projects producing a total of 8 million litres of biofuels per year over a two year period. The pilot programme has served the purpose of initiating activity on biofuels in Irish transport fuel supply. It has also demonstrated the level of latent interest in biofuels development with many Irish developers wanting to expand into this area.

Based on the experience of the Pilot programme, the Department of Communications, Energy & Natural Resources (DCENR) and the Department of Finance agreed upon an expanded excise relief which was announced in the 2006 Budget. The effect should be to deliver 163 million litres of biofuels per year onto the Irish market by 2008 and result in a 2% biofuels penetration. The current production of biofuels is about 8 million litres per year.



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