Bio Fuels Definition: Are They Really Good For The Environment?
Biofuels are fuels derived from biomass (i.e., plant material, algae, or animal waste). These feedstocks are readily renewable, so biofuels are considered renewable energy sources, unlike fossil fuels such as oil, coal, and natural gas.
Biofuels are recognized as a cost-effective and environmentally friendly alternative to petroleum and other fossil fuels. This is mainly due to high oil prices and the contribution of fossil fuels in light of the growing global warming crisis.
But, many critics have expressed concern about the scale of expanding certain biofuels due to the economic and environmental costs associated with the process and the potential to remove large amounts of farmland from food production.
Some well-established biofuels, such as wood, can be used directly as feed. Heat can also drive the internal electricity of a power plant to generate electricity. Many existing power plants burn grass, wood, or other organic matter.
Liquid biofuels are particularly interesting for their use, mainly because of the extensive transport infrastructure. The most efficient liquid biofuel is ethanol (ethyl alcohol), which ferments starch or sugar. Brazil and the United States are among the top ethanol producers.
In the USA, Biofuel ethanol is made primarily from corn kernels and is usually blended with gasoline to make “gasohol,” a fuel that contains 10% ethanol. In Brazil, ethanol-based biofuels are mainly produced from sugar cane and are typically used as 100% ethanol fuel or as gasoline blended with 85% ethanol.
Unlike “first generation” ethanol-based biofuels made from food crops, “second generation” cellulosic ethanol is made from low-grade cellulose-rich biomass, including sawdust, crop residues, and municipal solid waste. Cellulose ethanol is typically made from sugarcane pulp, a byproduct of sugar processing, or grasses that can grow in poor soil.
Cellulosic ethanol is mainly used as a fuel additive due to its lower conversion rate than first-generation biofuels.
The second most common source of biofuel is biodiesel, which is primarily pan-fried from oil-rich crops such as soybeans or palm oil but also in small amounts from other oil-rich sources such as refined cooking oil. Popular biodiesel in Europe is used in diesel engines and is usually mixed with petroleum diesel in various proportions.
Using algae and cyanobacteria as a source of “third generation” biodiesel is promising but economically challenging to develop. Some types of seaweed contain up to 40% lipids by weight and can be converted to biodiesel or synthetic oil. Some estimates suggest that algae and cyanobacteria can produce 10 to 100 times more fuel per unit area than second-generation biofuels.
Other biofuels include methane gas, which can be produced by decomposing biomass in the absence of oxygen, and methanol, butanol, and dimethyl ether, under development with biogas.
Ethanol (CH3CH2OH) is a renewable fuel produced from a variety of plant materials, collectively referred to as “biomass”. Ethanol is a blend of alcohol and gasoline that increases octane ratings and reduces carbon monoxide and other smog-causing gases.
The most common ethanol blend is E10 (10% ethanol, 90% gasoline) and is approved for use in most conventional gasoline vehicles up to E15 (15% ethanol, 85 % gasoline). Additionally, some flex-fuel vehicles are designed to run on E85 (a blend of gasoline and ethanol between 51% and 83%, depending on region and time of year), An alternative fuel that contains more ethanol than regular gasoline. About 97% of gasoline in the United States includes some form of ethanol.
Most ethanol is made from vegetable starches and sugars (mainly cornstarch in the United States). Still, scientists are concerned about its use of cellulose and hemicellulose, nonedible fibrous substances that make up most of the plant matter. So we continue to develop technologies that make it possible.
The most common method of converting biomass to ethanol is called fermentation. During fermentation, microorganisms (e.g., bacteria and yeast) metabolize plant sugars and produce ethanol.
Biodiesel is a liquid fuel produced from renewable resources such as new and used vegetable oils and animal fats and is a cleaner-burning substitute for petroleum-based diesel fuel. Biodiesel is non-toxic and biodegradable and is produced by combining alcohol with vegetable oil, animal fat, or recycled cooking oil.
Like petroleum-derived diesel, biodiesel is used as a fuel for compression ignition (diesel) engines. Biodiesel can be blended with petroleum diesel in any proportion, including B100 (pure biodiesel) and the most common blend, B20 (20% biodiesel and 80% petroleum diesel).
Renewable Diesel Fuel: Renewable diesel fuel is a biomass-derived transportation fuel suitable for diesel engines.
It is a commercial fuel manufactured in the United States and imported from Asia. Five plants in the United States have renewable diesel, with a total capacity of over 590 million gallons per year. Production is expected to increase in the near term, with 2 billion gallons of capacity at six plants currently under construction and expansion at three existing plants.
The US Energy Information Administration (EIA) does not report renewable diesel production; Still, we. The Environmental Protection Agency (EPA) reports that RFS RIN data show the US will consume more than 960 million gallons of her by 2020.
Due to the economic benefits of low-carbon fuels, nearly all renewable diesel fuel produced and imported into the United States is used in California.
It meets the ASTM D975 specification for petroleum in the United States and EN 590 in Europe.
Sustainable Aviation Fuel (SAF): SAF is a fuel derived from renewable sources that offer the potential to reduce life-cycle carbon emissions compared to conventional fuels. SAF is currently the commonly used preferred term for non-petrol aviation fuels and is formulated according to ASTM D7566 definitions.
SAF meets ASTM D1655 when blended with conventional aviation fuels and allows use in existing aircraft and products. SAF is commercially available in limited numbers and has been operating at Los Angeles International Airport since 2016 and at San Francisco International Airport in the late 2020s.
SAF’s domestic manufacturing facilities are operational in Los Angeles, many of which are under construction or planned, and began importing from international manufacturers in late 2020. The EIA reports no SAF production. But the EPA says RFS RIN data shows the United States consumed 4.6 million gallons in 2020.
Renewable Gasoline – Renewable gasoline, also known as biogasoline or “green” gasoline, is a transportation fuel derived from biomass that can be used in spark ignition engines.
Conforms to American specifications ASTM D4814.
European standard EN 228
What Makes Biofuels good?
As mentioned above, fossil fuels are a finite and eventually exhausted energy source. Biofuels are theoretically renewable as they can be easily replaced by creating more biomass.
Carbon. Biofuels are inherently better for the environment than fossil fuels because they are made from organic matter like plants, and plants remove carbon from the air.
However, this argument is more convincing than it might be hoped. If emissions savings are offset by the costs and emissions incurred during fertilization, transportation and services are part of the equation.
Cost-effectiveness. Bioethanol is cheaper than gasoline, so combining the two could be a great way to reduce costs in the transportation industry. The same applies to biodiesel and diesel. When fossil fuels are depleted, prices will inevitably rise. The sustainability of biofuels makes them more affordable.
Fuel consumption. Compared to fossil fuels, bioethanol and biodiesel have lower levels of chemicals such as chlorine and sulfur. This means that mixing with gasoline or diesel can dilute the concentration of these pollutants in the fuel source and produce cleaner carbon dioxide.
Logistics. Finally, biofuels can be produced locally, creating jobs in the same areas where they are used and reducing transportation costs and emissions associated with transporting vehicles to the point of sale.
What Makes Biofuels Bad?
Those concerned about energy security and carbon emissions see biofuels as a viable alternative to fossil fuels. However, biofuels also have drawbacks.
For example, it takes more ethanol than gasoline to produce the same amount of energy, and critics say ethanol production results in a net loss of power, raise food prices, and dramatically reduces the use of ethanol.
Fragile ecosystem. The oils needed to produce biodiesel often come from endangered habitats such as rainforests and sites with high biodiversity. Such land use displaces animal populations, destroys ecosystems, and affects biodiversity.
Adaptability. Not all biofuels are suitable for all vehicles. This is particularly true in the UK, as many car models have engines that cannot run on 100% biofuel blends. At the same time, biodiesel has low oxidation stability and a high freezing point, making it unsuitable for the aerospace industry.
Emissions. When primary biofuels are combusted to create heat (as happens most commonly in developing countries), they produce more significant amounts of local emissions than other forms of heating.
Biofuels are also controversial among environmental protection groups, arguing that biocultures are better used as a food source than fuel, fertilizer loss, and salinity.
Are Biofuels Environmentally Friendly?
As hinted above, both environmental pluses and negatives are associated with biofuels. Though they can offer various eco-friendly benefits for our planet, they can also entail detrimental consequences.
Much depends on the specific type of biofuel in question and how it is produced and consumed. Therefore, it’s advised to read up on the biofuel you have in mind before committing to its use as an everyday fuel source.