Biofuels, also known as agrofuels, are fuels produced from living organisms or from metabolic by-products like - plant biomass, vegetable oils, and treated municipal and industrial wastes. In order to be considered a biofuel, the fuel must contain over 80 percent renewable materials. Biofuels are considered neutral with respect to the emission of carbon dioxide. This is because the carbon dioxide given off by burning them is balanced by the carbon dioxide absorbed by the plants that are grown to produce them. The use of biofuels as an additive to petroleum-based fuels can also result in cleaner burning with less emission of carbon monoxide and particulates.
Three most common biofuel types are: Bioethanol, Biodiesel and Biogas.
Bioethanol refers to ethanol liquid which is made from common crops including sugar cane and corn; and mainly wheat in the UK. It is the principle fuel used as a petrol substitute for road transport vehicles.
Biodiesel is the biofuel substitute for diesel. It is usually made from plant oils or animal fat through a series of chemical reactions. In the UK, it is derived from oilseed based crops – mainly oilseed rape (OSR). Because biodiesel essentially comes from plants and animals, the sources can be replenished through farming and recycling.
Biogas is the biofuel substitute for natural gas, and consists of methane. It is created from organic waste materials including animal waste and waste generated from municipal, commercial and industrial sources, through the process of anaerobic digestion. In the UK, biogas is mainly generated through animal waste. Examples of solid biofuels are - dried manure, charcoal and wood.
There are various types of biofuel burners. These include - basic log stoves and boilers, straw bale burners, wood chip boilers and wood pellet stoves and boilers. Wood-fuelled heating systems generally burn wood pellets, chips or logs to power central heating and hot water boilers or to provide warmth in a single room. A true biomass burner must be able to burn a wide variety of biomass. Since biomass grows in various shapes and sizes, it needs to be made into a standardised shape, size and density - essentially a pellet, in order to use all forms of biomass in one burner. The raw material could be wood, or it could equally be any type of straw or grass or practically any other type of biomass residue. Through processing the biomass into pellets it makes it much easier to design a biomass burner which can efficiently work with the fuel. Therefore, biomass pellet stoves and pellet boilers are the only true biomass burner.
Biofuel carsThe aim of biofuel cars is to be carbon-neutral and to reduce greenhouse gas emissions as opposed to conventional transport fuels. And the price of biofuel cars is also much lesser than the conventional car fuels. However, it is worth noting that biofuel cars are not really carbon-neutral; because it requires energy to grow the crops and convert them into fuel. The amount of fuel used during this production does have a large impact on the overall savings achieved by biofuels. Even so, biofuels still prove to be substantially more environmentally friendly than their alternatives. Another benefit of biofuels is that, they save the drivers' money. In the UK, the Government has introduced many incentives to drivers of ‘green cars’ based on emissions – with reduced taxation; dependent on how environmentally friendly the car is.
On the other hand, a lot of the first generation biofuels are not sustainable. It is necessary to create sustainable biofuel production that does not affect food production, and one that doesn’t cause environmental problems.
To conclude, whilst biofuel cars massively reduce carbon emissions and help you save cash too; they could negatively affect the habitat of many species and aren’t necessarily energy efficient at the production stage.