Frequently Asked Questions
1. What is biofuel?
Biofuel is a generic term for fuels that can be produced from or are made up of a renewable material of plant or animal origin. Often they are substitutes or partial substitutes for fossil (or mineral) fuels. Biofuels used in transport are typically bioethanol which is used as a petrol substitute and biodiesel which is used as a diesel substitute.
2. What is biodiesel?
Biodiesel can be produced from any vegetable oil or animal fat and used as a substitute or partial substitute for mineral diesel. To produce biodiesel, these fats or oils are chemically converted to esters that have properties similar to mineral diesel. Biodiesel is often blended with mineral diesel and blends of up to 5 percent in mineral diesel are suitable for use in diesel engines without modification. Higher blends may be used in dedicated fleets.
3. What is bioethanol?
Bioethanol is an alcohol made from sugar, starch and products containing sugars and starches, through a process of fermentation and distilling, and used as a substitute or partial substitute for petrol. Bioethanol has properties that are similar to petrol and is often blended with petrol. Bioethanol is likely to be introduced as a low level blend (up to 10%) in some petrol. Higher blends may be used in dedicated fleets.
4. What is the difference between first and second generation biofuels?
First generation biofuels are produced from sugars, starches, vegetable oils or animal fats from proven technology. Examples include bioethanol from whey and biodiesel from tallow.
"Second generation" biofuels generally refer to new methods of producing biofuels. They are not yet ready for commercial development but are the subject of extensive research and development internationally. Examples include the conversion of plant lignin and cellulose into fuels by enzymes and the gasification of biomass material followed by a "gas to liquid" Fischer-Tropsch process. Biomass that could be used includes all types of trees, grasses, agricultural plant wastes, straw and algae.
5. What are the benefits of biofuels?
Using a biodiesel blend has a number of benefits, which are reduced net carbon dioxide emissions, reduced emissions of concern to air quality and human health, better fuel lubrication and reduced deposits in your diesel engine. Biodiesel is also non-toxic, biodegradable and speeds up the breakdown of any spills of diesel that it is blended with.
Using a bioethanol-petrol blend reduces net emissions of carbon dioxide and provides some air quality benefits. Bioethanol also has high octane.
6. Can biodiesel and bioethanol be made in New Zealand?
Yes. Biodiesel is being produced in New Zealand using tallow – a by-product of the meat industry – or canola oil and waste cooking oil. Bioethanol is being produced domestically from whey – a by-product of the dairy industry.
7. What countries currently use biofuels?
Biofuel blends are widely used around the world. The USA, Brazil, Canada, most European countries, Australia, China, India and Thailand all use biofuel blends.
8.Will the use of biofuels help New Zealand meets its Kyoto Protocol obligations?
Yes. If biofuels replace mineral fuels then their use will assist New Zealand in meeting its Kyoto Protocol obligations because emissions from the use of biofuels are not counted as greenhouse gas emissions under the Kyoto Protocol, whereas emissions from the use of mineral fuels are.
Quality of Biofuels
9. Is biofuel quality regulated?
Yes. The Engine Fuel Specifications Regulations 2008 regulate the minimum quality of all engine fuels including petrol, diesel, biodiesel, bioethanol and blends of these to ensure protection for consumers.
The regulations cover properties of the fuel that relate to vehicle operability, safety and the environment. An example of each of these is cold starting performance, flammability and sulphur content, respectively. The regulations are more stringent for fuel supplied in the retail market than where there is a written contract or supply agreement between the supplier and the end user. The regulations also cover minimum labelling requirements for retail fuel.
10. Can you use bioethanol-blended petrol in your car?
The Automobile Association website has a list of vehicles that support the use of bioethanol-blended petrol.
11. Can you use biodiesel-blended diesel in your vehicle?
Virtually all diesel engined vehicles can use biodiesel blends of up to 5% without any engine or fuel system modifications.
All biodiesel-blended diesel for retail sale in New Zealand must meet fuel specifications regulated by the government so you can be confident about its quality. Biodiesel-blended diesel must meet the same requirements as ordinary diesel, such as those relating to cold temperature performance. The biodiesel in biodiesel-blended diesel has good combustion and lubrication properties, making it good for your engine.
12. Will you be able to change between biofuel blend fuel and ordinary fuel?
Yes. You can have both bioethanol-petrol blends and petrol, or biodiesel- diesel blends and diesel in your tank at the same time and there should be no noticeable effect changing between renewable biofuel blends and conventional fuels.
13. Is bioethanol suitable for marine and aviation applications?
The use of ethanol-contained fuels is discouraged in marine and strongly discouraged in aviation applications. This is because of the presence of water. The bioethanol can separate out of the fuel into a bioethanol water layer which could cause an engine to stop. In aviation use, cold temperatures at altitude can result in easier bioethanol separation with any water from the air condensed in the fuel tank. Bioethanol blends are specifically excluded by the Federal Aviation Authority which sets the standards for aviation safety in the USA.
The situation with respect to marine applications is less clear. Marine use increases the risk of the presence of water in the fuel tank. However, many of the major outboard motor manufacturers accept the use of ethanol blends up to 10% with their engines and in a number of states in the USA the marine use of ethanol blends is encouraged because fuel spills are less environmentally damaging with these fuels.
14. Are biofuels suitable for motorcycles, and small engines like lawn mowers and chain saws?
Bioethanol-petrol blend fuel can generally be used in both 4-stroke and 2-stroke engines used in land-based applications. It is best to check with the equipment manufacturer first.
Back to Top