Published on June 26th, 2012 | by Yellow Magpie0
Biofuels: Exploring The Realities And The Myths
Biofuel Miscanthus Photo By Scott Bauer
Biofuels have become the buzzword in the 21st century. This term and the industry surrounding it promise to bring us clean, renewable energy without the negative side-effects of fossils fuels such as oil and coal. Perhaps not unexpectedly it has attracted much attention and out of this acute focus many claims and misconceptions have been writ and spoken.
If ever a new fuel source has been wrongly associated with untruths and uninformed conjecture it is this industry. In this post Yellow Magpie will take a closer look and examine the reality and the hype of the new game in town – biofuels.
The Myths And Misconceptions
There are many myths surrounding biofuels. We will briefly address some of the main ones.
Biofuels effect food production.
This is simply not true. Roughly 12 per cent of the world’s landmass is used for agriculture. The land used for the biofuels is but a tiny fraction of this number.
In fact, many biofuels are grown in land that is not suitable for agriculture as the soil is either too arid or too nutrient-poor to sustain crops.
Biofuels Can Provide All The Solutions To Our Energy Needs?
Not every biofuel provides a net energy gain. Some such as corn crops struggle to provide a net energy gain after processing and transportation costs are taken into consideration.
However, some biofuels do provide a healthy net energy gain. Biofuels are particularly energy dense. For example, plant oil contains 37 megajoules of energy per kilogramme. This compares very favourable to both coal (24 megajoules per kg) and dry timber (16 megajoules).
Biofuels will never be capable of satiating the world’s energy demand on their own. The problem is that our energy usage worldwide is expanding at an incredible rate. There is only a finite amount of land available and so alternatives to be used in conjunction with biofuels have to be developed.
All Biofuels Are Economically And Environmentally Beneficial
There is a notion that all biofuels are good. Whilst many types of biofuel are healthier for the environment than current fuel production methods this is not always the case.
Professor of Alternative Energy Chris Somerville in an interview for the Open University stated: ‘I think there are some types of so-called biofuels that could be very negative for green house gas emissions. Partially through kind of indirect effects, that is, if you grow biofuels on a drained swamp in Malaysia that’s going to be very negative because as soon as you drain a swamp the greenhouse gas emissions out of that swamp will dwarf the rate at which the plants that you plant can possible take up the CO2 for a century or more.’
Biofuels that stem from grasses have one key disadvantage when it comes to economics and efficiency. If the processing plant is not positioned no farther than 80 kilometres (50 miles) away producing biofuel becomes economically unfeasible.
Why Does Misinformation Happen?
New technologies have a habit of attracting hyperbolic statements, both for and against, which are often far too removed from reality to be taken seriously. Industry spin and people getting caught up in the adventure lead to statements being issued that overleap the facts.
Conversely, all new inventions are disruptive technologies which mean that there is always something at stake and something to be displaced. Someone always stands to lose and the new technology is viewed as a threat.
You do not have to have a personal stake in the petrochemical industry as everyone has a vested interest in energy. People have habits and have a tendency to stick with what they know. Sometimes when misinformation occurs there is no conspiracy just a bias towards the familiar.
Biofuels And Fossil Fuels
Both biofuels and fossil fuels are derived from plants that have obtained their energy from the Sun. The key difference between the two is duration. Biofuels have been recently removed and are easily grown again while fossil fuels have been there for millions of years and millions of further years are required from them to be replenished.
Whereas biofuels are essentially crops that can be grown again and again, making them renewable, fossil fuels are a once-off and are non-renewable.
Another key difference is to realise that nearly all plants and woody matter realise carbon dioxide (CO2) as they decompose. Burning timber and such plants for fuel produces the same amount of CO2 as natural decomposition – save for a much shorter timescale. Burning fossil fuels just adds to the amount of carbon dioxide in the atmosphere with no easy way to remove it.
Confused Terms: Carbon Offsetting And Neutral
Two terms that are often confused are carbon offsetting and carbon neutral. Carbon neutral applies to things like biofuels in which the carbon is neither removed nor added to the atmosphere in the long term.
In a carbon neutral cycle such as in biofuels crops are grown taking carbon out of the atmosphere as their main source of food. When the plant is processed and burnt as a fuel the carbon that it has trapped is released back into the atmosphere. The cycle is repeated as new crops are grown and burnt with the net result being that the amount of carbon in atmosphere remains the same.
In fossil fuels the carbon that is released from burning fuels such as oil and gas is not reabsorbed normally. Carbon offsetting allows the carbon used to be absorbed by growing extra trees to recover the amount of carbon released to the atmosphere.
Biofuels: Not One – Many
It is important to understand that there are many different types of biofuel. From methane gases to liquid such as ethanol and biodiesel to woody plants that are burnt directly to obtain energy.
Here are some of the main biofuel crops:
Miscanthus and switchgrass are some of the most common forms of biofuels.
Grasses such as Miscanthus grow especially quickly to heights in excess of four metres (13 feet). The fact that they are rhizomes also provides another key advantage as their underground stem system allows them to quickly spread. Although if they are not managed correctly the fact that they rhizomes makes them difficult to contain.
Switchgrass is another crop suitable for biofuels that grows rapidly in poor soils that have a low nutrient content.
The Arid Agave
One of the most amazing of arid plants that may be of great benefit to the biofuel industry is Agave. Agave is a cactus-like plant that thrives in arid conditions. Certain species use up to ten times less water than common crops such as rice or wheat. Yet these plants can produce much more sugar than sugar cane which makes them ideal as an energy source.
The Woods: Willow
Willow may also become an important tree crop for the biofuel industry. The fact that the tree can be coppiced (the stem cut to produce several stem offshoots) every three to five years for up to 30 years makes it a highly efficient source of energy.
Willow may become a cornerstone in the biofuel world if scientists can discover how break down the sugar-rich lignin that gives all wood its strength. If they succeed than even more energy can be freed from this tree increasing efficiency.
Biodiesel And Ethanol
Biodiesel and ethanol, sometimes referred to as bio-ethanol, are two liquid-fuels that are being used to power internal combustions engines across the world. Biodiesel is used on its own to power diesel engines while ethanol is blended with petrol.
Biodiesel produce less emission than regular diesel combustion. It also has another benefit that of cleaning tanks and engines of carbon deposits. Much of biodiesel is derived from oilseed rape. This crop yields roughly 1,300 litres per hectare.
There are many vehicles in Scandinavia that are being powered by biogas which is often methane gas. One of the main benefits of biogas, apart from its high levels of cost and energy efficiency is that it can be obtained from waste.
Food waste, cattle emissions, sewage treatment plants, and landfill sites can all be great forms of low-cost biogas.
The Impending Energy Crisis
Currently, we are living in a age in which the worldwide demand for energy has never been greater. Countries such as India and China are developing rapidly and need more and more energy. This is being mirrored in many other developing nations as modernity makes its presence felt.
Chris Somerville notes:
‘World energy use is currently expanding by about one billion watts, or so-called gigawatt, every 1.6 days…I guess everybody knows what a watt is from light bulb so think about a 100 watt light bulb well a billion watts is the of a large nuclear power plant. One way of thinking about it is that energy use is expanding worldwide by about the output of one nuclear power plant every 1.6 days.’
With such demands it becomes inevitable that biofuels will form part of the solution to this impending energy crisis.
Hopefully, we will chose biofuels that give as much net energy as possible as well as bioefuels that do not harm both food production and the environment.
Visit Wikipedia for more information on Biofuels.
You may also wish to check out Yellow Magpie’s Soap And Water: The Best Way To Build Infrastructure, Graphene: The Vanguard For A Technological Revolution and 3-D Printing: A Glimpse Into The Future.