Did you say biofool or biofuel?
Buses powered by beans and cars fuelled by carrots? DANIELLE DU TOIT investigates biofuels – what they are, why we need them and why this solution is necessary for the future of our health
It is no secret that we need a solution to our oil woes, the price of petrol and diesel, our worries about global warming and those dreaded greenhouse gases (GHG). The solution may be the organisms we share the planet with.
How can they help? Through carbon fixation – a process whereby living organisms reduce carbon dioxide (CO2) into organic compounds; also known as the biofuel making process.
According to research conducted by the Worldwatch Institute’s Climate and Energy Programme, global production of biofuels has increased by 17 percent – with 105 billion litres produced in 2010 (up from 90 billion litres in 2009).
Many factors are behind the surge in biofuel production. Rising oil prices have led many to seek energy sources elsewhere. This, coupled to instability in the oil-rich countries, has also added fuel to the fire, so to speak. Other factors include a global economic rebound and new legislative mandates in countries that are big biofuel producers.
Three main types of biofuels are available – biodiesel, bioalcohol and biogases. It’s important to know that diesel engines, called compression-ignition engines, and petroleum engines, called internal-combustion engines, require different properties from the fuels that power them.
Diesel engines are combustion engines that use the heat of compression to create ignition to burn the fuel, which is injected into the combustion chamber. Petroleum engines are internal combustion engines which make use of a spark plug to ignite a fuel and air mixture.
So what is it that makes biofuel special compared to conventional fuel sources?
Biodiesel is the most commonly used type of biofuel – so much so that in Europe it is blended with regular mineral diesel to make a five percent biodiesel blend that’s available at most fuelling stations. Diesel engines that run on biodiesel generally don’t experience any problems and, in most cases, tend to run more smoothly. In fact, most manufacturers now recommend the five percent blend.
Biodiesel is manufactured through a chemical process called transesterification, where glycerine is separated from fat and vegetable oil. The process leaves behind two products – methylesters (chemical name for biodiesel) and glycerin (a by-product that can be sold for use in soaps and other gylcerin-based products).
Biodiesel has better lubricating properties than mineral diesel and reduces engine wear, which in the long term is great. However, a downside to biodiesel is that it gels or crystallises at low temperatures, but this is dependent on which vegetable product is used in the manufacture. Canola-oil-based biodiesels tend to coagulate at roughly -10°C while tallow (an animal by-product) biodiesel coagulates at +16°C.
Organic replacements for petrol
Bioalcohol, another popular biofuel, is manufactured by certain bacterial processes. The most commonly used bioalcohols are ethanol, butanol and propanol. They’re popular because they can be synthesised chemically or biologically. Another advantage is that they have high octane ratings. The higher the octane number, the more compression the fuel can withstand before it ignites – leading to fuel economy.
Ethanol is the most commonly used bioalcohol, and can be substituted into petrol engines instead of regular petroleum. It is already being used the world over as a fuel additive. A blend of ethanol and petrol is used; this 15 percent ethanol mixture can be used in any automobile petrol engine. Ethanol has other benefits too: due to the high compression rate, it releases very few particulates into the air, and it can also run at much higher exhaust-gas recirculation rates.
Brazil, the second largest producer of ethanol in the world, has a long history of producing ethanol from sugar cane – dating back to 1900. From 1931, vehicles began to need an ethanol/petroleum blend, and Brazil has continued to make significant contributions to the next generation of biofuel technology. These include the processing of natural oils in refineries and the conversion of waste cellulosic substrates to ethanol. Brazil plans to build 103 new cane mills by 2019, which will increase its production capacity by 66 percent.
Butanol, a stronger organic alcohol, is more similar to petroleum than ethanol in terms of octane levels and detonation properties. A regular automobile can run perfectly on a blend of 85 percent butanol/petroleum as opposed to the 15 percent in ethanol biofuels. Butanol blends better with other fuels, and is less resistant to blend separation should the fuel be contaminated with water.
Butanol contains more energy per given volume than ethanol and almost the same energy per volume as the petroleum we make use of today – but it’s more difficult to produce than ethanol and propanol.
The global demand for butanol is over 4,5 million tonnes per year. Green Biologics, a British-based biotechnology company, says that the demand for butanol is likely to increase to approximately 122 million tonnes per year by 2020.
Biogas fuel (usually just called biogas) is a form of fuel created by a decomposition process of organic materials, as with the previously-mentioned biofuels. However, while decomposition takes place, the resulting released gases (usually hydrogen, nitrogen and methane) are harnessed and react with oxygen to create energy. This energy is concentrated and compressed, and used for vehicle transportation.
Biogas is already successfully in use in numerous European countries and has produced such great results that beverage giant Coca-Cola invested in 14 26-tonne Iveco Stralis trucks after a year-long trial determined that renewable biomethane-powered vehicles were not only sustainable but delivered a 50,3 percent saving on GHG emissions (compared to the same vehicle running on diesel). The big trucks also produced 85,6 percent less nitrogen oxide than a diesel-fuelled truck.
Biogas-powered vehicles are currently more expensive than diesel-fuelled vehicles. However, the North American petroleum company CHS Cenex has said that while the total cost of vehicle ownership would increase by 15, 3 percent, with escalating oil prices and biogas already being 12,8 percent cheaper than diesel, the choice to own a gas-powered vehicle becomes an easy one.
The desperate need for biofuel?
Rising oil prices are a huge influencing factor with regards to biofuel production, and we’re all aware of the critical global warming crisis we face – but another influencing factor we need to take into account is our own health.
A carcinogen is any substance that is an agent directly involved in causing cancer – benzene is known to be a human carcinogen, and is known to be a component in exhaust fumes.
Human rights and environmental organisations are trying to get legislation passed whereby school buses will be the first public transport vehicles to be “converted” to biofuel, and the US government is being pressured into passing laws that prevent idling of buses and vehicles.
Air pollution affects us all daily – from short-term effects such as headaches, nausea and irritation of the eyes, nose and throat, to infections and respiratory problems such as asthma and emphysema. More serious effects of include lung cancer, respiratory disease and even damage to the brain, liver, kidneys and nerves.
It isn’t just hippies, environmentalists and business leaders under pressure to appear “green” who can benefit from biofuel. Everyone who is conscious of their health, or the health of their loved ones, should grasp this technology. We’d be fools not to.