Types of Biofuels





Biofuels are a family of fuels obtained from organic material known as biomass. They are an attractive alternative to fossil fuels like gasoline because unlike fossil fuels, biofuels are readily renewable. Additionally, thanks to the chemical similarity between them and fossil fuels, many biofuels can easily be used with current vehicles and machines with only small modifications needed. Biofuels are gaining in popularity mainly due to the rising oil prices around the world and the fact that more and more countries are introducing very strict pollution regulations. Many biofuels can also be produced without the need for complex technology, making them ideal for developing countries. There are a few types of biofuels in use today. They can be divided into three categories: bioalcohols, biodiesel, and biogas.

Bioalcohols

The main bioalcohol fuels used today are ethanol and to a lesser extent methanol. Methanol is the simpler and less energy-rich fuel of the two. It is most commonly produced by gasification of biomass into a hydro-carbon rich gas called “syngas” from which methanol is then obtained. While the process itself is not costly nor complicated, it is only suitable for large scale production due to the large quantities of biomass needed. Methanol has approximately half the energy content of gasoline while at the same time costing much, much less and producing about 20% less toxic emissions.

Ethanol is more energy rich when compared to methanol although it is still slightly less energy rich than gasoline itself. The most popular method of production of ethanol is simple fermentation of sugar. Sugar can come from a number of crops depending on the geographical location. Currently, the gasoline used in many countries around the world contains up to 10% of ethanol to offset the price. Ethanol is particularly popular in Brazil where many cars have a so called “Flex” engine which can be run on pure ethanol or gasoline or a mixture of both.

Another bioalcohol is butanol. It is not as widespread as the previous fuels due to a more complex production process but it is the most similar to regular gasoline and can readily be used in gasoline-only engines.

Biodiesel

Biodiesel is created through mixture of an organic oil, most commonly vegetable oil, and an alcohol. This process of converting oils to biodiesel is known as transesterification. While plant-based oil is the most common ingredient in biodiesel, other types of oils can be used such as animal fat or algae. Biodiesel is a substance very similar to diesel however modern diesel engines cannot use it readily as an energy source without slight modifications to the engine. The biodiesel available at gas stations is mixture of 5% biodiesel and 95% ordinary diesel fuel. However, more biodiesel friendly vehicles are being produced, chief amongst them are railway cars which can run on up to a 20% biodiesel mixture. Some hobbyists also convert diesel to complete biodiesel powered vehicles.

The only problem with biodiesel is the fact that, while bioalcohols use any biomass to produce energy, biodiesel must be produced from oil rich crops, which require large amounts of fertile land. This is a problem as it increases the costs of biodiesel and uses land that could have been used for food production or other purposes.

Biogas

Biogas is created by the fermentation of organic materials such as manure, crops, sewage and biomass. It is produced by enzymes and organisms breaking down the organic material in an oxygen free environment as anaerobic (no oxygen) digestion is necessary.

More and more people are beginning to see the advantages of biogas. Some dairy farmers, who have to deal with large amounts of manure, have began to make use of this resource to produce electricity and sell it to their community. However, biogas plays a much more prominent role in developing countries such as India or in less developed regions of China. People in these places build small biogas production systems, known as an anaerobic digester, which are fed on household waste and manure and supply a single household with fuel used for heating and cooking. These systems are easy to construct, maintain, use and offer many advantages to the users such as: saving money, eliminating the need for expensive infrastructure, reducing the need for firewood, producing electricity, and eliminating what is often waste biological matter.

Biohydrogen

Hydrogen is thought to be the fuel of the future by many. It has a very high energy content and produces virtually no pollution. The only problem at the moment is that 98% of pure hydrogen produced today comes from fossil fuels. However, researchers are working on an ecological method of creating this fuel — they plan to use bacteria that feed on biomass and as a result produce clean and ecological hydrogen. This would make hydrogen production completely fossil fuel independent.

There are many types of biofuels that serve as excellent alternatives to fossil fuels. All of them have certain advantages and disadvantages making them more or less suitable for use in certain locations and climates but the abundance of them means that they are still available to almost anyone. The biggest advantage of biofuels is that they allow for the production of clean energy. Another advantage is that most of them can be produced locally by low-tech means. This makes them ideal for developing countries where transportation or distribution of fossil fuels is expensive.

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