Biofuels powers vehicles, heats homes, and to cook. Biofuels can be used, in either pure form or blended with fossil fuels, in diesel-powered vehicles and boats. Biofuels are also commonly used as solvents in perfumes or varnish as disinfectants in medicines to increase octane and improve the emissions quality of gasoline
Emerging research suggests that algae may someday prove to be a valuable component in the solution to the planet’s growing energy demand. According to scientists from ExxonMobil, photosynthetic algae have many advantages that make them a compelling alternative fuel source. Algae produce fatty, lipid cells containing oil that can be used as fuel. Growing algae consume carbon dioxide, offsetting greenhouse gases. Algae grows in areas that are deemed unsuitable for growing plants or crops. This is a benefit over other biofuels, which are produced on farmland that could be used for food crops or forestland that has been cleared of trees (causing environmental concerns). Algae may yield greater volumes of biofuel per acre than other sources.
The past decade has shown that algae will not be economical anytime soon as a replacement for other fuels (Forbes), but research investments are continuing. University researcher Ken Reardon is utilizing a $2.1 million grant to grow algae more sustainably for biofuel production. In 2018, ExxonMobil and Synthetic Genomics, Inc. announced they were moving into a new phase of research aimed at producing 10,000 gallons of algae-based biofuel by 2025.
Ethanol is a clear, colorless liquid made from plant materials. Its use is widespread in the US and Brazil. Several steps are involved in making it: Biomass feedstocks - such as corn, sugarcane, wood residues or crop residues – are grown and/or collected at an ethanol production facility Feedstocks are converted to ethanol at the production facility, then transported to a fuel terminal by train, truck or boat Ethanol is blended with gasoline to make “flex fuels” in the US and Brazil.
Brazil is second only to the US in ethanol fuel production, and the two countries together dominate the market – producing 85% of the world’s supply. Brazil’s thriving ethanol industry relies on its agricultural technology, large amount of cultivatable land and abundance of inexpensive sugarcane that can be used in ethanol production.
Brazil’s use of biofuels took off in the mid-1970s after the first global oil crisis. The Brazilian government put a plan into motion in 1975 to phase out fossil fuel-based fuels in favor of ethanol made from sugarcane. Cars in Brazil are required by law to run on gasoline-ethanol “flex fuel” blends and many can and do run on pure ethanol, though the higher cost often makes this a less likely choice.
One of the problems with ethanol is that the process of converting plants into fuel consumes energy, offsetting the gains. There is strong debate in the US over whether the Net Energy Gain (NEG) from ethanol is positive because producers must convert corn into sugar before it can be distilled into ethanol – an energy-intensive process. By comparison, the sugarcane-based ethanol industry in Brazil is more cost effective because sugarcane has seven times the energy equivalent of corn, making the NEG positive. Despite the debate, ethanol production in the US continues to grow and reached a peak annual production rate of 16 billion gallons in early 2018.
Biodiesel is made through a chemical process called transesterification. This process separates the glycerin from animal fats or vegetable oil, leaving behind methyl esters (the chemical name for biodiesel) and glycerin (a valuable byproduct used in soaps and other products).
The demand for biofuels, especially ethanol, is expected to increase globally in the coming years, although rising food prices, trade tensions and social unrest are prompting a debate on the hopes for running more cars and trucks on biofuel.
In the transportation sector, ethanol is the most widely used liquid biofuel in the world. The US and Brazil are the world’s top ethanol fuel producers, accounting for 89% of the world’s production. The International Energy Agency (IEA) Renewables 2018 Market Analysis predicts that ethanol will account for two-thirds of the worldwide growth in conventional biofuels between 2018 and 2023.
Biofuels currently make up 3.1% of the total road transport fuel in the UK or 1,440 million litres. By 2020, 10% of the energy used in UK road and rail transport must come from renewable sources – this is the equivalent of replacing 4.3 million tonnes of fossil oil each year. Conventional biofuels are likely to produce between 3.7 and 6.6% of the energy needed in road and rail transport, while advanced biofuels could meet up to 4.3% of the UK's renewable transport fuel target by 2020.