What is a Biofuel?
Biofuel is a fuel that is derived from biomass, that is, plant or algae material or animal waste. Since such feedstock material can be replenished readily, biofuel is considered to be a source of renewable energy, unlike fossil fuels such as petroleum, coal, and natural gas.
Biofuel is commonly advocated as a cost-effective and environmentally benign alternative to petroleum and other fossil fuels, particularly within the context of rising petroleum prices and increased concern over the contributions made by fossil fuels to global warming.
Many critics express concerns about the scope of the expansion of certain biofuels because of the economic and environmental costs associated with the refining process and the potential removal of vast areas of arable land from food production.
What Generation Is Your Biodiesel?
Biofuel research and development have led us to three different generations of biofuel. Each generation has a unique feedstock and its own potential benefits and drawbacks. There are three types of biofuels: 1st, 2nd, and 3rd generation biofuels.
When we talk about first-generation biofuel, we are referring to biofuels from an existing row crop such as corn ethanol or soy biodiesel. Second-generation biofuels are derived from cellulosic biomass such as perennial grasses. Third-generation biofuels are to be made from algae.
1. First-generation biofuels
First-generation biofuels are derived from vegetable oil, starch, or sucrose. Processing these elements to become a transportation fuel requires simple biochemical treatments for vegetable oil to biodiesel or starch and sucrose to ethanol.
These processes have already been developed in the food industry, limiting the need for further research and development before producing transportation fuels. However, those crops require intensive agricultural input (fertilizer), as opposed to less input for perennial grasses.
2. Second-generation biofuels
Second-generation biofuels are expected to be derived from cellulosic biomass sources including crop residues, perennial grasses, and trees. They may be grown on marginal cropland where row crop production is not profitable. By focusing on areas that are highly erodible or have marginal soil quality, avoids competition with fertile ground that may be best used to grow food crops.
Although these crops require little initial input, they do require additional treatment to break down cellulose for creating an end product such as a liquid fuel. In addition, transporting high quantities of biomass can be a logistical and financial challenge for producers.
3. Third Generation Biofuels
To create third-generation biofuels biomass or oil is harvested from algae. Oil-producing algae (so call Oilgae) does not require pretreatment and grows quickly. However, controlling the environment for optimal growth is challenging, and expensive. Maintaining strict environmental control often requires expensive facilities and equipment.
Types of Biofuels
There are three common types of biofuels, which include:
1. Ethanol
Ethanol is pure alcohol or ethyl alcohol and is probably the most common alternative biofuel used in motor vehicles today. Ethanol can be made using different sources, but the most commonly used are sugarcane and corn.
IN 2011, the U.S government approved the use of ethanol blends up to 15% for use in motor vehicle models manufactured after 2011. Ethanol blends of up to 10% have been in use for a long time without any need for modifying the engines. The main question all along has been whether ethanol is sustainable as a biofuel alternative.
Ethanol is made by fermenting sugars derived from sugarcane or corn, and it contains oxygen, which helps a vehicle’s engine efficiently burn fuel, reducing emissions. In the U.S., most ethanol comes from corn, and fuel is made up of 10% ethanol and 90% gasoline.
Brazil is the second-largest producer of ethanol after the U.S., and its fuel is composed of 27% ethanol, and they use sugarcane as the primary feedstock.
2. Biodiesel
Biodiesel is becoming more popular, and it mimics traditional petroleum-based diesel. Biodiesel is, however, derived from recycled cooking grease, animal fat, and vegetable oils. Most biodiesel companies tend to collect used cooking oil from restaurants and convert it into usable biodiesel, which can be blended with conventional petroleum diesel.
Some military vehicles, trucks, and buses in the United States use fuel blends composed of up to 20% biodiesel as pure biodiesel may be compromised by frigid weather, causing complications in older engines.
3. Biobutanol
Biobutanol is the lesser-known fuel among the three biofuels, but it has the most potential. Biobutanol is iso-butanol made from algae or bacteria, instead of animal or vegetable fats like biodiesel. Standard gasoline engines can use Biobutanol without prior engine modification.
Biobutanol is mostly derived from fermenting sugars from the organic feedstock. The most commonly used method of producing Biobutanol is fermenting simple sugars found in biomass feedstock. The by-product of this fermenting process is butanol, in addition to acetone and ethanol.
Biobutanol can reduce carbon emissions by a significant 85% compared to gasoline, which makes it a more viable alternative to gas and fuels that are a blend of gasoline and ethanol. At very high concentrations, biobutanol is mixed with traditional petrol instead of ethanol for use in unmodified engine models. Research has proven that biobutanol is usable in unmodified engines at 100 percent.
4. Biogas
This is the gaseous form of biofuels. It burns just like natural gas and for this reason, is slowly but steadily taking its place. Biogas is mainly composed of methane gas though produced from the process of anaerobic breakdown of biomass. Most agricultural firms use biogas and the fuel is currently being packaged in gas cylinders for household use.
The fuel is extracted from a mixture of both animals and plants because each contributes a specific element. For instance, plants have significant carbon and hydrogen in them whereas animals have nitrogen in them. These elements are essential for coming up with biogas.
What are some pros and cons of biofuels?
| Pros of Biofuels | Cons of Biofuels |
| Green energy -comes from natural sources | Not enough land space to grow crops to generate biofuels |
| Renewable form of energy- constantly replenished by nature | Global decline in food production-As more land is directed towards biomass production |
| Helps keep the environment clean- low level of greenhouse gas emissions | Can cause prices of staple crops to increase due to decreased availability of land |
| Improved utilization of land and waste | Might lead to global hunger and malnutrition due to inflating food prices |
| Reduction in landfill sites | Can put a strain on water resources-High water demand for the cultivation of biomass and in the production process |
| As efficient as gasoline | Most vehicles are not equipped to utilize biofuels |
| A large number of sources are available for the production of biofuels | Huge startup investment required |
| Reduces burden on a single energy resource especially fossil fuels | High production cost |
| Employment generation due to increased local production | Not preferred by many as it can erode some metals, rubber, and plastic parts |
| Economic security – countries can become self-sufficient by providing for themselves | Might lead to deforestation to make way for biomass crops |
| Comparatively safe technology that is easier to implement as well | Funding required for research and development |
| Easily blends with existing fuels | Biodiversity loss as land consumption pattern changes |
| Lower pollution compared to burning fossil fuels | Not viable when compared to solar and wind power |
Advantages of Biofuels
1. Efficient Fuel.
Biofuel is made from renewable raw materials and is relatively less flammable compared to fossil diesel. It has significantly better lubricating properties. It causes fewer harmful carbon emissions than standard diesel. Biofuels can be made from a variety of materials. The total cost-benefit ratio is much higher.
2. Cost-Benefit
Biofuels will now cost the same on the market as gasoline. However, the total cost-benefit ratio is much higher. They are cleaner fuels, which means they produce fewer emissions when burned. With the increased demand for biofuels, they have the potential to become cheaper in the future too.
3. Durability of Vehicles’ Engine
Biofuels are adaptable to current engine designs and work very well in most conditions. It has higher cetane and better lubricating properties. When biodiesel is used as a combustible fuel, the life of the engine is increased.
4. Easy Source
Gasoline is refined from crude oil, which happens to be a non-renewable resource. Although current gas storage facilities will last for many years, they will end at some point in the near future. Biofuels are made from many different sources, such as liquid manure, crop waste, other by-products, algae, and plants that are specially grown for fuel.
5. Renewable
Most fossil fuels expire and one day they end in smoke. Since most sources such as manure, corn, switchgrass, soybeans, crop, and plant waste are renewable and unlikely to run out anytime soon, using biofuels in nature is efficient. These plants can also be replanted again and again.
6. Reduce Greenhouse Gases
Studies suggest that biofuels reduce greenhouse gases by up to 65 percent. When burned, fossil fuels produce large amounts of greenhouse gases; i.e., Carbon dioxide in the atmosphere. These greenhouse gases trap sunlight and cause the planet to warm up.
7. Economic Security
Not every country has large reserves of crude oil. For them, the import of oil is an enormous burden on the economy. As more people switch to biofuels, a country can reduce its dependence on fossil fuels. The production of biofuels increases the demand for suitable biofuel crops and gives agriculture a boost.
8. Reduce Dependence on Foreign Oil
While locally grown crops have reduced the country’s reliance on fossil fuels, many experts believe it will take a long time to meet our energy needs. With crude oil prices skyrocketing, we need more alternative energy solutions to reduce our dependence on fossil fuels.
9. Lower Levels of Pollution
Because biofuels can be made from renewable resources, they cause less pollution on the planet. However, this is not the only reason biofuels are being promoted. When burned, they release less carbon dioxide and other emissions than standard diesel. Its use also leads to a significant reduction in PM emissions.
Disadvantages of Biofuels
1. High Cost of Production
Despite all of the advantages associated with biofuels, they are quite expensive to produce in the current marketplace.
2. Monoculture
Monoculture refers to the practice of producing the same crops year after year, rather than producing various crops through a farmer’s fields over time.
3. Use of Fertilizers
Biofuels are made from crops, and those crops need fertilizers to grow better. The disadvantage of using fertilizers is that they can have harmful effects on the environment and cause water and Agriculture pollution.
4. Shortage of Food
Biofuels are made from plants and plants with high sugar content. However, most of these plants are also used as food crops. Even if vegetable waste material can be used as raw material, the need for such food crops remains. It will take up agricultural land from other crops, which can cause a number of problems.
5. Industrial Pollution
The carbon footprint of biofuels when burned is smaller than that of conventional fuels. However, the process by which they are made makes up for it. Production is largely dependent on a lot of water and oil. It is known that large industries that are supposed to produce biofuels emit large amounts of emissions and also cause small amounts of water pollution.
6. Water Use
Irrigation of biofuel crops requires large amounts of water which, if not managed carefully, can put a strain on local and regional water resources. To produce corn-based ethanol to meet local demand for biofuels, huge amounts of water are used that could not put sustained pressure on local water resources.
7. Future Rise in Price
Current biofuel production technology is not as efficient as it should be. Scientists are busy developing better ways that we can get this fuel. However, the cost of research and future installation means that the price of biofuels will increase significantly.
8. Changes in Land Use
If the land is used to grow a biofuel feedstock, it has to be cleared of native vegetation, which then leads to ecological damage
9. Global Warming
The biofuels, which are mainly hydrogen and carbon, produce carbon dioxide, which contributes to global warming. While biofuels cause fewer greenhouse gas emissions than fossil fuels, this can only serve to slow global warming, not stop it or reverse it.
10. Weather Problem
Biofuel is less suitable for use at low temperatures. It is more likely to attract moisture than fossil diesel, which causes problems in cold weather. It also increases the microbial growth in the engine which clogs the engine filters.
Resources:
- DOE Office of Science Biological and Environmental Research Program
- 2021 Department of Energy Office of Science Biological Systems Science Division Strategic Plan
- Biofuels basics from DOE
- DOE Office of Science biofuels centers
- Big Help from Small Microbes: Electron Transfers to Produce Fuels and Fertilizer
- Oxygen: The Jekyll and Hyde of Biofuels
- Driving to Great: Science and the Journey to Waste-Free Biodiesel
- Science Highlight: Adding Ozone Lowers the Heat for Biofuel Combustion
