The history of biofuels goes back for millennia. Wood used for cooking and heating can be considered biofuel as it converts solar energy and carbon captured in the wood in to heat and light. However, when talking about biofuel in contemporary terms the word generally refers to gaseous and liquid fuels obtained from biological sources.
One the earliest examples of liquid biofuel is the use of refined vegetable oil used in torches for lighting which was popular for centuries until the invention of electrical lighting.
Jumping to more recent times in 1900 Rudolph Diesel showcased the first diesel engine at the Paris World Exhibition running it on peanut oil – a biofuel.
This was a major innovation on the road to modern fuels. In another significant innovation in 1918 gasoline was first blended with alcohol to produce motor fuel. By the 1970s and 80s biofuel was becoming recognised as an alternative or an additive to fossil fuel. As prices of oil continued to rise research and development of biofuels increased.
Modern environmental concerns also promoted the development of biofuels as they are considered greener than oil based fuels, (although there is some controversy around the production processes). Biofuels are generally considered carbon neutral as the materials used have already captured carbon from the atmosphere when the feedstock was grown and biofuels emit fewer greenhouse gases when burned.
Wikipedia defines biofuel as, ‘fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels such as oil. Biofuel can be produced from plants or from agricultural, domestic or industrial bio-waste.’
Biofuels can be classified in to four major groups according to how they are produced. First generation biofuels are those obtained from food crops for example biodiesel and bioethanol made from vegetable oil.
Second generation biofuel comes from organic waste that doesn’t compete with food production. It includes the use of used cooking oil and urban waste and thus is considered greener as it recycles existing materials and reduces dumping at landfills.
Second generation biofuels include renewable diesel (HVO), sustainable aviation fuel (SAF), biogas, and biomethane. The third and fourth generations of biofuel are major current trends; the area where major innovations are foreseen in the next few years as demands for cleaner and cheaper fuel alternatives increase.
Third generation biofuel is derived from algae and other aquatic plants that contain at least 50% natural oils. Senegal and Mauritania are already researching the innovative use of Typha, an aquatic, invasive plant, to create biofuel. The use of algae and other aquatic plants still needs extensive research and innovation to become financially worthwhile on a commercial scale.
The fourth generation of biofuels are largely in the research phase of production. Scientist are looking into genetically modified micro-organisms including microalgae, yeast, fungus and cyanobacteria to photosynthesize CO2 into fuel. Continuous research into biofuels as an alternative to fossil fuel is an exciting trend that promises productive results in the near future.
The most common types of biofuel are biodiesel – considered a sustainable fuel; renewable diesel – usually made from vegetable oil: biogas used for cooking and heating; bioethanol used as an additive to petrol and diesel; biobutanol which can be used an additive or as a replacement for oil based fossil fuels, and biomethane which can replace natural gas. It can be used to generate electricity and power vehicles.
An exciting current trend is the increasing use of biofuel in some of the most polluting sectors of the transport industry – shipping, road and rail. The aviation sector is a major contributor to global warming so the trend to create innovative sustainable aviation fuel (SAF) using biofuels is crucial.
The Zimbabwean economy has benefitted from biofuel for decades. Green Fuel (Pvt) Ltd began producing smaller quantities of bioethanol in 2011. After major ongoing expansion projects, they now produce around 120 million litres of ethanol annually plus, once their current expansion is completed, the plant is forecast to produce up to 225 MW of electricity for an estimated 225,000 homes in urban and rural areas.
They have two estates and based in the South East of the country, in Chisumbange and Middle Sabi, and a state of the art factory in Chipinge. At the factory sugar cane is processed in to ethanol as an additive to petrol. Besides Green Fuel’s ethanol plant there is a growing trend in government to encourage contract farmers to grow jatropha crops for processing into biodiesel. The project is expected to assist with poverty alleviation in some rural areas.
The future of biofuels in Zimbabwe looks bright.
Text: Michael Knott
From: E&P ISSUE 11