What are Biofuels?

Biofuels are a renewable fuel that can be produced from biomass. Biomass is the technical term for (mostly) plant or animal matter. Some examples of products used as biomass include: corn, barley, sugar cane, soybeans, canola and although is usually considered to be plant matter, biofuels can also be derived from fishery products or municipal wastes, food industry and byproducts and wastes. Biofuels can be solid, liquid, or gaseous, but the two most common types are ethanol and biodiesel. The two main strands of biofuels can be broken down into primary and secondary biofuels: primary refers to products such as fuelwood, wood chips and pellets, organic materials; all used mainly for cooking or electricity purposes. Secondary biofuels result from processing biomass (plants and other organic materials) into a liquid such as ethanol and biodiesel that is used for vehicles and industrial purposes. Biofuels are mainly used in homes (80%), while industrial use is around 18% and liquid biofuels used in transport only account for approximately 2%.

The History Behind Biofuels:
Biofuels have actually been used since man first discovered fire. Biofuels were used for many different applications, but it suffered quite a lot after the discovery of fossil fuels such as coal, gas and oil. Rudolf Diesel, the inventor of the diesel engine designed it to run off off peanut oil. Later on the Ford Model-T was designed and made to run off hemp derived from biomass, back when hemp was one of America's major industries. It wasn’t until World War II that there was once again a demand for biofuels because of the increased use of imported fuel. This mainly occurred over in Germany where they had a shortage of fuel. Many inventions took place at that time, one of which being the discovery of alcohol that was derived from potatoes. The use of biofuels slowly became to drift away after that. No one really need to use them because there was just so much crude oil available at the time. Nowadays, people are finally realizing that it won’t be much longer before oil supplies will deplete and an alternative fuel will need to take its place. Today, thousands
of experiments are being conducted to try and not only find more effective ways to produce biofuel, but to also show the world that it can be used as an alternative fuel source.

Uses of Biofuels:
Biofuels are becoming more and more popular in the transportation world. Whether it be from bulk transport of raw materials or the local city bus, many

are going green and using engines that function on biodiesel and electricity. Most commonly, biodiesel is used in large farm equipment. There are two possibilities for the application of vegetable oils to internal combustion engines: adaption of the engines to the fuel (vegetable oil engines) and adaption to the fuel to the motor (trans esterification process). However since vegetable oil is much more viscous than conventional fossil fluids, it reduces fuel flow and sometimes cause the pistons in the engines to reduce speed and cause
Aside from the modified machines to run on vegetable oil biodiesel there are many versatile engines that can take on mixes of biodiesel and ethanol’s (alcohol) with little to no modifications. Along with being a renewable source of fuel, biodiesel emission rates are drastically lower than those of fossil fuels and petroleum based fuel sources. As shown in the figure to the right, when using biodiesel emissions of CO2 lower greatly. Also biodiesel is safe to transport since it is biodegradable and has a very high flash point (lowest temperature at which it can vaporize to form an ignitable mixture in air). One may come across B100 or E100, what these mean are Biodiesel 100% and ethanol 100% concentrations used to power the engines of cars
built to run on Biodiesel and/or ethanol.

How Biofuels are Produced?
There are many different kinds of biofuels, each with a similar detailed process on how to produce them. Animals fats, oils and vegetables contain glycerin, and are thus called tryglycerides. Everything gets turned into what is called esters, which separates the glycerin. At the end of the process you end up with the biofuel on the top and the glycerin on the bottom. This process is called transesterification.
Producing biofuel is a rather simple process compared to producing other fuels. It's so easy that with the right equipment, you can produce it at your own home!
There are various types of plants that can be used to produce biofuel.
Some of these are:
- Sugar crops or starch that can be fermented to produce ethanol
- Natural oils from plants that can be burned directly in the engine or mixed with other fuels such as petroleum (also known as biodiesel)
- Wood and all the by products can be converted into a liquid base such as methanol or ethanol

Steps to produce the biofuel using vegetable oil:
  1. Filtering - Waste vegetable oil is filtered to remove all other particles such as small bits of food that are left over.
  2. Removal of Water - The liquid oil is boiled at 100 degrees C to remove the water. This allows the reaction later on to happen faster.
  3. Titration - This is the most important stage of the whole process: a test is done to determine the amount of lye (catalyst) that is needed in the reaction.
  4. Preparation of sodium methoxide - methanol is mixed with sodium hydroxide to produce sodium methoxide.
  5. Heating and mixing - Residue is heated between 120-130 degrees F and mixed well.
  6. Settling and separation - after cooling the biofuel will separate and lay on the top while the glycerin, which is much heavier, will sink to the bottom.

Various Methods to Produce Biodiesel:

Batch Process
This process starts off by adding a catalyst to an alcohol base. Then the oil itself is added to the mixture. At this point in the process the whole system is closed off to prevent any loss of alcohol. The temperature of the mixture is then set just above the boiling point of alcohol (70 degrees C), but for safety reasons many prefer to have the reaction take place between room temperature and 55 degrees C. The reaction usually occurs between 1-4 hours depending on the temperature (for every 10 degrees C increase the rate of reaction doubles). After the reaction a centrifuge is used to separate the liquids. You are left with the glycerin by-product- the biodiesel. In some cases the biodiesel must be purified to remove extra residue.

Supercritical Process
The is an alternative to the transesterification method. It uses supercritical methanol at high temperatures and pressures. The reaction between the methanol and the oil occurs very rapidly (almost spontaneously). In this reaction the oils are converted into methyl esters.

Ultrasonic Diesel Process
During the process of making biodiesel, the combination of slow reaction kinetics and poor mass transfer decrease the biodiesel yield and quality. Ultrasonic reactors are capable of improving these kinetics using less methanol and less catalyst (up to 50% less) in the reaction. Biodiesel is conventionally produced using the batch process (using heat and mechanical mixers). Ultrasonic mixing can produce a much more effective product than then the traditional processes (coming out with a biodiesel yield of 99%). Not only is ultrasonic processing a more effective way of producing the fuel but it is also extremely fast reducing the processing time from 1-4 hours (batch process) to less than 30 seconds and the separation time from 5-10 hour to approximately one hour. The steps of ultrasonic processing of biodiesel include:
  1. The vegetable oils and animal fats are mixed with the methanol or ethanol and the sodium or potassium methoxide or hydroxide.
  2. This is then heated to a temperature between 45 and 65 degrees C.
  3. The mixture is then sonicated inline for 5-15 seconds.
  4. A centrifuge is used to separate the glycerin.
  5. The converted biodiesel is then washed with water.

Microwave Method
Scientists are constantly trying to design new ways to alter the transesterification process and explore new ways of trying to produce a useful biofuel. Microwaves have been introduced into laboratories because the amount of energy that is capable of being transferred directly into a sample far exceeds what thermal heating can do. This means that chemical reaction can occur much faster. The same process is used as the batch process (add the oil to the mixture of methanol and the catalyst), but, when put into a microwave this process is accelerated. This is still a new concept to the production of biofuels, but seems to be quite effective if it is able to be produced on a larger scale.

Lipase-Catalyzed Method:
There has been a lot of research on the use of enzymes as a catalyst for transesterification. It has been discovered that lipases make the reaction less sensitive to FFA content which is a problem they have in the biodiesel process. The only problem they have with using lipases is that methanol can’t be used in the reaction because the two cancel each other out. In this case methyl acetate is used instead. This process actually turns out to be a much more cost effective way of producing biofuels.

Reactions that take place in the process of making biodiesel:
Triglycerides are reacted with an alcohol (such as ethanol) to give ethyl esters of fatty acids and glycerol:

O2CR1 - O2CR2 - O2RC3
3 OH
O2R1 - O2R2 - O2R3
3 OH
(Triglycerides) + (Ethanol) ----> (Methyl Esters, aka Biodiesel) + (Glycerol)

Transesterification reaction in skeleton form:
Skeleton Form

3D Representation

General equations for all hydrocarbon combustions:
O2(g) + Fuel(l) ---> H2O(g) + CO2(g)
Compared to petroleum products that also produce carbon monoxide:
O2(g) + Fuel(l) ---> H2O(g) + CO2(g) + CO(g)

Different Types of Biofuels:

There are many different types of biofuels that can be made from various plants, animals, waste materials and much more. The most common biofuel in the world is biodiesel E10 fuel. This is a mixture of 10% ethanol and 90% petroleum. Recently with new discoveries and technology the formula has been improved to produce E15 fuel, E20 fuel, E85 fuel, E95 fuel and even E100 fuel which consists of just ethanol and up to 4% water. The E10 biodiesel is the most popular in Europe and you can actually purchase it at many petrol stations. It is so popular because it can be mixed with mineral diesel and the engine doesn't need any type of modification for it to run on the fuel. Some other types of biofuel include fuels made from vegetable oil; butanol which is usedto replace petroleum; and biogas which is produced from various biodegradable waste materials. With new advances in technology researchers are experimenting with "secondary generation biofuels" which includes biomass to liquid technology. Some examples include biohydrogen, biomethanol and mixed alcohols.

Pros and Cons of Biofuels:

Numerous studies have been done on biofuels to prove the many benefits it has. Right off the start biofuels are biodegradable; produced by organic materials. This means that it is a renewable fuel source, unlike petroleum based gasolines. Local farmers have the ability to produce the crops which means that we wouldn’t have to rely on unstable sources of oil. We would be able to constantly produce the crops to harness the fuel from. Producing this type of fuel is one of the cheapest in the world and very little vehicles need to be modified to burn the fuel. Aside from just using crops, think about all the fast food restaurants and the waste vegetable oil that just goes to the dump. All of that could be combined at a factory and then reused to power our vehicles instead of just going to the landfill. On the environmental side all of the biofuels produced are “carbon neutral”. The amount of carbon dioxide produced when burning the fuel itself is equal to the amount that the plants themselves can absorb. In turn no extra carbon dioxide will be produced and remain in the atmosphere. The amount of harmful emissions produced doesn't even come close to the large amount produced by burning gasoline.

Although it seems like everyone should switch to using biofuels, there are still many problems with doing so. In order to start using biofuel on a large scale acres of land would have to be cleared so that the crops needed to make the fuel can be produced. The result of this would be massive loss of habitat for various species of plants and animals. There is also a concern for the amount of production of food because many farmers would divide there land and start producing crops for biofuel rather then for food. In fact 60 percent of todays soy crops would have to be used for the production of biofuels. This would drastically increase the price of food everywhere, especially in developing countries. Such a large amount of crops would have to be grown that the value of the fuel produced would be decreased because of the large amount of fuel that would be needed to grow the crops themselves. An effective way of producing the fuel itself has yet to be discovered. Biofuels actually require more energy to produce then they give off, which has been an issue for a long time. Over the years scientists have made many discoveries on a more efficient way of producing the fuel, but its still not worth it to produce it on a large scale. A study in 2005 showed that producing ethanol from corn required 29 percent more than the energy that it is capable of generating. The power that comes from this fuel just doesn't compare to what you can get out of regular gasoline or even diesel. It is said that biofuels have little no no effect on the environment but it has been discovered that they can be a contributor to things like smog. They emit large amounts of nitrogen oxides which in some cases effects people that have respiratory illnesses.

Production and Cost:
Biofuels have been brought onto the world’s table environmentally and economically as a way of reducing harmful emissions put into our atmosphere from burning fossil fuels. Although this may seem like a new idea to many in the western world (because of our ever-increasing gasoline prices), South America has been producing and burning biofuels for decades; since the 1970s.The idea of exchanging fossil fuel-created gasoline with a fuel made from plants seems like the perfect solution to our environmental crisis, but there are many factors to consider when producing and consuming biofuels instead of the gasoline and diesel that we use on a daily basis. Factors such as: clearing land for crops that will be converted into biofuel, growing those crops, having locations specifically capable of converting the biomass into fuel, dispensing the biofuel in a fashion that is convenient and cost-effective, and having vehicles capable of running on this type of fuel.

In order for biofuel to become as popular and widely used as gasoline and diesel are now, manufacturers would need to make the cost at least competitive with that of it’s contenders. The cost of production of commercial grade regular gasoline in 2006 was $0.51USD. The production of biofuel in the same year ranged from $0.3USD (from sugar cane) to $0.8USD (from cereals or maize). Currently, the commercial cost of biofuel mixes (such as E85) are comparable to that of premium unleaded gasoline, depending on country. Just like the price of gasoline wavers depending on transportation costs and accessibility, the cost of ethanol-gasoline mixes and other biofuels raise and lower, depending on yearly crop yields, processing costs, feedstock costs, and other factors. Figure 2 shows relative costs between gasolines and biofuels.


Environmental Impact:
The appeal of using biofuels in today’s transportation vehicles (cars, trucks, trains, planes, etc.) is that this would cut down on air pollutants that these vehicles expel into the air after having burnt up petroleum (fossil fuels). These pollutants, including carbon dioxide, methane, and nitrous oxide, among (many) others, are known to cause health problems and are believed to be a major player in global warming. In order for the general public to be able to use personal vehicles and keep our living environment safe to live in, it makes sense that researchers and government officials alike would begin to look for different ways to power our vehicles.
Biofuel, when burned as bioethanol or biodiesel, shows significant figures in pollution reduction compared to conventional regular gasoline in all types of vehicles-- from small compact cars, all the way up to pick-up and transport trucks. Table 1 shows the environmental impact of burning bioethanol and biodiesel in comparison to gasoline. Under “Environmental Impact”, one can see that the CO2 emission reduction is large. Sugar cane bioethanol (also the cheapest to produce) yields a 90% reduction rate from regular gasoline. This explains why countries like Brazil and much of South America produce such great amounts of the fuel; it’s both cheap, and better for the environment. The difficulty with bringing this type of mass production of sugar cane biofuel to North America would be the land required to grow such vast amounts of sugar cane to turn into bioethanol. Most of the United States’ land suitable for farming this crop is already growing a crop that would otherwise need to be imported from other countries.


The decrease in pollution from the burning of biofuels is remarkable, and although the environmental impact of producing the fuel is less as well, it isn’t as great of a difference. The crops that are turned into bioethanol or biodiesel still need to be shipped to production plants (mind you, the means of transportation to get there could be running on biofuel as well), unless the plants are immediately next to the crops, which is unlikely. Then the refined biofuels must be transported to where they will be distributed (“gas” stations”), although this could also be done using vehicles running on bioethanol.

Research of Biofuels:

New Advancements (March, 8/ 2011):
Researchers as the departments BioEnergy Science Centre have successfully produced a fuel called isobutanol which is very similar to that of gasoline. This was produced just from materials such as corn stalks and switchgrass. The challenge that they had to face was chemically dismantling a plant’s cellulose. A scientist was able to develop a strain of “Clostridium cellulolyticum”, which is a native cellulose-degrading microbe. This allows to complete a process called consolidated bioprocessing which saves costly steps in producing the biofuels. The reason that scientist have chosen isobutanol instead of ethanol is because its energy density, octane level, and volatility is much closer to gasoline. Also, it is possible to use this fuel in vehicles without and modifications to the engine itself. Although this is only a study it will be involved with many other tests to try and modify the fuel itself to increase its performance, environmental impact and much more.

Biofuel from Inedible Plant Material Easier to Produce:
A group of scientists based at Cambridge University identified and studied genes for two enzymes that toughen wood, straw and stalks. These make it difficult to extract sugars and produce bioethanol’s. This knowledge can now be used in crop breeding programs to make non-edible plant material that requires less processing, less energy and fewer chemicals for conversion to biofuels or other renewable products and therefore have an even lower overall impact on atmospheric carbon.Head of the project, Professor Paul Dupree stated that: "There is a lot of energy stored in wood and straw in the form of a substance called lignocellulose. We wanted to find ways of making it easier to get at this energy and extract it in the form of sugars that can be fermented to produce bioethanol and other products."Dupree goes on to explain that further development and work with colleagues is needed to develop new types of bioenergy crops. As the worlds fossil fuel and oil reserves deplete it is essential that we find green alternatives to create biofuels and renewable plant products. Dupree concluded with: “This research is aimed at improving our ability to release energy stored in plants in a form that is usable in normal everyday applications.”

Coffee Grounds for Biodiesel?
To most, used coffee grounds are seen as garbage, but chemical engineers have discovered that they can be used as a versatile source of energy. By extracting the oils out of the coffee they can then convert it into a biodiesel. 15 percent of the coffee grounds themselves are oil which is only a little less then that of other materials used for biodiesel production. Researches from Starbucks did many tests and were able to convert 100 percent of the oil to biodiesel using methanol and potassium hydroxide (catalyst for the reaction). With such as large amount of coffee drank around the world each day, the amount of used coffee grounds is extremely large. It is estimated that if the used coffee grounds in the US alone were converted into biodiesel then they would be able to make a profit of about $8 million. On a worldwide scale that number would increase quite a lot.

Algae Becomes Biodiesel:
There aremany countries that have very limited land that can be used for growing crops, but they have an alternative. The ocean is a breeding ground for algae. Muchresearch is still being done, most of which is more inland. They arehaving problems phasing out some of the more undesirable strains of algae which can take over the kind that is capable of being turned into biodiesel. Also, harvesting algae in the open ocean is a slight problem. GreenFuels Technology Corporation has developed a bioreactor system the produces “clean air biofuels” from algae. It is grown using smokestack emissions which is capable of growing algae year-round. At the same time this process reduces NOx by up to 86% and CO2 by 40%. To replace all transportation fuels in the US you would need about 140 billion gallons of biodiesel. The amount of land to grow the crops would work out to be about 450 million acres of land to grow these crops and 500 million acres of grazing land for animals. These numbers just aren’t possible, but with algae it is.
Algae being grown for production of biofuels

Whiskey By-products Used to Produce Biofuels:
Edinburgh Napier University has just recently patent for the product of biofuel made from whiskey. It took them the last two years to develop the product. The biofuel uses two main by-products from the whiskey production process; “pot ale”, the liquid from the copper stills and “draff”, the used grains. Those are the basis to produce the butanol that can be used as fuel. This fuel is capable of completely replacing regular gasoline but it is more practical to add only like 5 or 10 percent of the biofuel into the gasoline. This would make a significant difference because that is 5 or 10 percent of oil that is saved.

Fourth generation biodiesel
Large companies doing research in the advancement of biodiesel production and manufacturing have introduced new “bio-chemical” and “bio-thermal” processes. Pyrolysis, gasification and genetic manipulation to secrete hydrocarbons are all part of the new processes. With thermal depolymperization of biological waste they can extract methane and other oils to produce biodiesel. These new ways of developing fuel and producing what they call “green gasoline”, “green aviation fuel” and “green diesel.