Over the past century, global warming and non-renewable energy have become ever-growing problems for our planet. A move towards using more sustainable methods of transportation is vital if we wish to continue living in the way to which we have become accustomed.
One way of doing this is by using renewable energy in transportation, such as cars, buses, and airplanes. Renewable energy simply refers to an energy source that will replenish itself on a relatively short timescale.
A possible renewable fuel that could be used is ‘biofuel’. Biofuel, as the name suggests, is an energy source derived from organic material, and ranges from alcohol to firewood.
Over the article, the different types of biofuels, how they are formed, and where they are being used will be discussed.
What Are The Main Types of Biofuels that Can be Used in Transportation?
The term ‘biofuel’ is generally used to refer to ethanol and diesel, but there are several different forms of biofuels that all have specific advantages.
Biodiesel: The most commonly used biofuel, biodiesel is similar to conventional diesel and can be used in conjunction with conventional diesel in most new vehicles. In chemical terms, it is a ‘fatty acid methyl’.
Vegetable Oil: A common site in most kitchen cupboards, the vegetable can also be used to power transportation. Though in most countries the main purpose of the oil is to aid the production of biodiesel, in warmer climates it can also be used as pure fuel in diesel engines.
Biogas: This is a naturally produced gas that is the same as ‘landfill gas’, which forms from anaerobic digesters.
Bioalcohols: There are several naturally produced alcohols that can be used as fuels. The most common of these is ethanol, which can be used in older car engines. Another important alcohol is butanol, which can be directly used in gasoline engines and is very energy efficient.
The chemical structure of ethanol. Image Credit: www.in.gov
Syngas: This is produced by converting organic material into gases like hydrogen and carbon monoxide, and then into energy by a process of pyrolysis (thermal decomposition without the aid of oxygen). It can be used in various applications.
How are Biofuels Produced?
In theory, any carbon source can be turned into a biofuel. Generally, the source of carbon used for biofuels plants, as either biomass (from living plants) or biowaste (e.g. decomposed plants).
Bioalcohols: In the production of ethanol and other alcohol-based biofuels, fermentation of sugar crops and starch is used, during which enzymes and microorganisms break the sugar and starch down into usable fuels.
Biodiesel: Biodiesel is formed by mixing plant waste with sodium hydroxide and methanol. It can also be produced from fats and greases, and from soy and vegetable oil. The method by which biodiesel is produced is called ‘transesterification’ which reacts fats or oil with alcohol.
Vegetable Oil: Plants naturally produce oil, which can then be heated to be used directly in diesel engines. Examples of plants that produce oil include oil palm, soya bean, and algae.
Transesterification process for biodiesel
What are The Benefits of Using Biofuels in Transportation?
One of the major benefits of using biofuels is that it reduces CO2 emissions. Burning conventional fossil fuels releases greenhouse gases into the atmosphere, which can lead to global warming. However, as biofuels are produced from plant materials, the plants used in the production of these fuels actually absorb carbon dioxide from the atmosphere. It is thought that the use of biodiesel produces around 60% less carbon dioxide relative to fossil fuels.
Furthermore, biofuels are renewable, and so will not run out- unlike fossil and nuclear fuels.
Other important benefits of biodiesel include: It can be mixed with diesel in cars and buses, it is non-toxic and biodegradable and therefore is of no threat to humans, and it only ignites at extremely high temperatures
What are the Drawbacks of Using Biofuels In Transportation?
Biofuels do have drawbacks, however. The biggest issue is the loss of biodiversity, because if biofuel is used heavily then only certain types of crops will be grown, meaning certain species of flora and fauna will have no natural habitat. Also, large areas of the vital rainforest could be lost if it is replaced by palm oil or sugar cane plantations.
Also, though biofuels release fewer greenhouse gases into the atmosphere, some critics say that as much energy is used in the farming of the crops used and the production and processing stages.
Furthermore, many climate researchers say that the focus should be on reducing energy use entirely, not replacing the energy we use with a different source. The production of biofuels may take attention away from the ultimate goal.
Examples of Biofuels Being Used In Transportation
The use of biofuels has increased exponentially over the last decade, and between 2000 and 2005 the output of biodiesel increased by a factor of four.
The primary producing nations of biofuel are Brazil, USA, France, Sweden, and Germany.
The USA produces more biofuel than any other country and is looking to replace 75% of imported oil with biofuels by the year 2025. The biofuel program in the USA is currently heavily subsidized, with over 200 different available subsidies.
Brazil is one of the world’s top producers of biodiesel, which it produces from sugarcane. 60% of cars here run on 85% ethanol.
Brazil Fuels Growth of Sugar-Based Ethanol
The Canadian government has recently announced that it will be investing $1million in Pond Biofuels, which will help to increase sustainability in Canada’s cement industry.
In the UK, biofuels make up around 3% of the total fuel used, which equates to around 1440million liters. The target in the UK is to have 10% of transportation energy sourced from biofuels by 2020.
Sources and Further Reading