Biofuels
By Ayush Choudhary
What are Biofuels?
A
biofuel in any type of fuel in which the energy derived from the process of
biological carbon fixation. Biological carbon fixation occurs in living
organisms. The biggest difference between a biofuel and a fossil fuel is the
time period over which the fixation occurs. In a biofuel, fixation occurs in
months or years. In a fossil fuel, fixation occurs over thousands or millions
of years. Additionally, fossil fuels are made entirely of hydrogen and carbon
atoms while biofuels contain carbon, hydrogen, and oxygen.
Biofuels are designed to replace gasoline, diesel fuel and coal,
which are called “fossil fuels” because they are made from animals and plants
that died millions of years ago. Biofuels are made mostly from plants that have
just been harvested.
There are three main types of biofuel. Ethanol, biodiesel, and biojet fuel. Ethanol is used in engines that burn gasoline, like most cars.
Biodiesel is used in engines that burn diesel fuel, like large trucks and
tractors. Biojet fuel is used in planes.
An
overveiw
Biofuels have been around as long as cars have. At the start of
the 20th century, Henry Ford planned to fuel his Model Ts with ethanol, and
early diesel engines were shown to run on peanut oil.
But discoveries of huge petroleum deposits kept gasoline and
diesel cheap for decades, and biofuels were largely forgotten. However, with
the recent rise in oil prices, along with growing concern about global warming
caused by carbon dioxide emissions, biofuels have been regaining popularity.
Gasoline and diesel are actually ancient biofuels. But they are
known as fossil fuels because they are made from decomposed plants and animals
that have been buried in the ground for millions of years. Biofuels are similar,
except that they're made from plants grown today.
Much of the gasoline in the United States is blended with a
biofuel—ethanol. This is the same stuff as in alcoholic drinks, except that
it's made from corn that has been heavily processed. There are various ways of
making biofuels, but they generally use chemical reactions, fermentation, and
heat to break down the starches, sugars, and other molecules in plants. The
leftover products are then refined to produce a fuel that cars can use.
Countries around the world are using various kinds of biofuels.
For decades, Brazil has turned sugarcane into ethanol, and some cars there can
run on pure ethanol rather than as additive to fossil fuels. And biodiesel—a
diesel-like fuel commonly made from palm oil—is generally available in Europe.
On the face of it, biofuels look like a great solution. Cars are
a major source of atmospheric carbon dioxide, the main greenhouse gas that
causes global warming. But since plants absorb carbon dioxide as they grow,
crops grown for biofuels should suck up about as much carbon dioxide as comes
out of the tailpipes of cars that burn these fuels. And unlike underground oil
reserves, biofuels are a renewable resource since we can always grow more crops
to turn into fuel.
Unfortunately, it's not so simple. The process of growing the
crops, making fertilizers and pesticides, and processing the plants into fuel
consumes a lot of energy. It's so much energy that there is debate about
whether ethanol from corn actually provides more energy than is required to
grow and process it. Also, because much of the energy used in production comes
from coal and natural gas, biofuels don't replace as much oil as they use.
For the future, many think a better way of making biofuels will
be from grasses and saplings, which contain more cellulose. Cellulose is the
tough material that makes up plants' cell walls, and most of the weight of a
plant is cellulose. If cellulose can be turned into biofuel, it could be more
efficient than current biofuels, and emit less carbon dioxide.
History of biofuels
- Biofuels are nothing new. In
fact, they've been around as long as cars have. Henry Ford originally
designed the Model T to run on ethanol. And people have been running
diesel engines on vegetable oil much longer than they have been running
diesel engines on petroleum-based diesel fuel.
- Rudolf Diesel, inventor of the
diesel engine, originally designed it to run on vegetable oil. In fact,
one of his early demonstrations, at the World Exhibition in Paris in 1897,
had a diesel engine running on peanut oil.
- Petroleum based fuel originally
won out over biofuel because of cost. The table is slowly turning though
as fossil fuels become more expensive.
- During World War II, the demand
for biofuel increased once again as fossil fuels became less abundant.
- Biofuel surged in popularity
during the energy crisis of the 1970s.
- The most recent surge in
biofuel popularity occurred in the 1990s in response to tougher emissions
standards and increasing demands for enhanced fuel economy.
Classification
of Biofuels
- Biofuels are often broken into
three generations.
- 1st generation biofuels are
also called conventional biofuels. They are made from things like sugar,
starch, or vegetable oil. Note that these are all food products. Any biofuel
made from a feedstock that can also be consumed as a human food is
considered a first generation biofuel.
- 2nd generation biofuels are
produced from sustainable feedstock. The sustainability of a feedstock is
defined by its availability, its impact on greenhouse gas emissions, its
impact on land use, and by its potential to threaten the food supply. No
second generation biofuel is also a food crop, though certain food
products can become second generation fuels when they are no longer
useful for consumption. Second generation biofuels are often called
“advanced biofuels.”
- Though not a traditional
category of biofuel, some people refer to 3rd generation biofuels. In
general, this term is applied to any biofuel derived from algae. These
biofuels are given their own separate class because of their unique
production mechanism and their potential to mitigate most of the
drawbacks of 1st and 2nd generation biofuels.
Energy Content of Biofuels
- The energy content of biodiesel
is about 90% that of petroleum diesel.
- The energy content of ethanol
is about 50% that of gasoline.
- The energy content of butanol
is about 80% that of gasoline.
- Most biofuels are at least as
energy dense as coal, but produce less carbon dioxide when burned.
- The lower energy content of biofuels
means vehicles travel shorter distances on the same amount of fuel. This
has to be taken into account when considering emissions.
Some biofuels
Ethanol
Ethanol is another word for alcohol made from grains. It is the
same alcohol that people drink and it can be produced from corn, barley, wheat,
grass, sugar cane, and a number of other things.
Ethanol is often used as a biofuel. In most countries, it is
mixed with gasoline to create a blend that is sometimes referred to as gasahol.
In the United States, the mixture is usually 10 percent ethanol and 90 percent
gasoline. This is referred to as E10 and it can be used in any car that burns
gasoline. Some cars are known as flexible fuel vehicles or flex fuel for short.
These cars can use gasoline that contains as much as 80 percent ethanol. In
Brazil, some cars can run on 100 percent ethanol, which is widely available in
that country thanks to its abundant supply of sugar cane.
Ethanol can be made from any of the following feedstock:
- Corn
- Sugar cane
- Sugar beet
- Wheat
- Grass
- The inedible parts of most
plants
Biodiesel
Biodiesel is a term applied to any diesel fuel that is made by
refining oil, fat, or grease collected from plants and animals. The most common
oil used to produce a biodiesel is vegetable oil. Like gasoline, standard
diesel fuel is often blended with a biodiesel. The most common blend is 20
percent biodiesel and 80 percent regular diesel. This blend is known as B20.
Though B20 is most common, blends can range from 2 percent biodiesel all the way
to 100 percent biodiesel.
Biodiesel can be made from any of the following feedstock:
- Jatropha i.e. A cactus-like
plant
- Camelina i.e. A flowering plant
- Soybeans
- Rapeseed i.e. A kind of seed
- Canola Oil
- Palm Oil
- Peanut Oil
- Vegetable Oil
- Animal Fat
- Algae oil i.e. Oil made by
algae that live in water
Current
Trends
- Most gasoline and diesel fuels
in North America and Europe are blended with biofuel.
- Biodiesl accounts for about 3%
of the German market and 0.15% of the U.S. market.
- About 1 billion gallons of biodiesel
are produced annually.
- Bioethanol is more popular in
the Americas while biodiesel is more popular in Europe.
- The U.S. and Brazil produce 87%
of the world's fuel ethanol.
- More than 22 billion gallons of
fuel ethanol are produced each year.
- Ethanol is added to gasoline to
improve octane and reduce emissions.
- Biodiesel is added to
petroleum-based diesel to reduce emissions and improve engine life.
- Concerns about the global price
of food have resulted in many nations revising (downward) plans for biofuel
production and use
Thank you!
And
please ,
Save fuel!!
By
Ayush choudhary
X-A
