Biofuels: Ethanol, Biodiesel, Biobutanol, Methanol

1. Bio fuel:
Ethanol, Biodiesel,
Biobutanol, Methanol
 Paper 305
Unit IV Environmental
biotechnology

2. 1
Introduction

3. Introduction
As on 31 March
2018, India had estimated
crude oil reserves of 594.49
million tonnes and natural
gas reserves of 1339.57
billion cubic meters

4. Hence the discovery of Biofuel!
• What is Biofuel: A biofuel is a fuel that is produced through contemporary processes from biomass, rather than a
fuel produced by the very slow geological processes involved in the formation of fossil fuels.
Here we are
going to
discuss 4
major
biofuels
Ethanol
Methanol
Biobutanol
Biodiesel

5. Ethanol
• Ethanol is a combustible chemical which is usually produced
by fermentation of high starch and sugar content crops like
corn, sorghum, barley and sugar cane.
• Microbially produced ethanol has high values in western
countries like USA & Brazil.
• Blending ethanol with gasoline in a standard ratio of 1:9 is
being used to fuel automobiles and other combustible
engines.
• Fermentation of ethanol involves microbial degradation of
plant starch amylases and amyloglucosidases, this is further
fermented into ethanol.
So the use of corn to make ethanol is the ultimate solution?
We wish climate crisis could be solved this easily!

6. Limitations of using Ethanol
• Using corn and other feedstock for production of ethanol has
reduced our dependency on gasoline but it has contributed
to higher worldwide food prices of these crops.
• It absorbs water and cannot be shipped through existing
pipelines because they almost always contain some water.
• So ethanol must be distilled twice to remove the water: once
when it is generated and then again after its shipping. This
adds to the production cost and ultimately higher prices.
• Ethanol is relatively toxic to microbes and therefore only
limited concentration of ethanol can accumulate in
fermentation process.
• Ethanol has relatively lower energy per unit volume(EPV)
than butanol and gasoline.

7. Production of Ethanol
• Crop residues are the plant materials left
behind after the harvest. This materials
consists of cellulose and hemi-cellulose,
polymer of glucose, xylose, mannose,
galactose, and arabinose.
• While no microorganism naturally ferments
all five sugars, an Escherichia coli strain that
expresses Zymomonas mobilis genes is able
to ferment all these sugars and this
ferments twice as rapidly as traditionally
used yeast.
• The use of thermophillic organism like Thermoanerobacter ethanolicus is even more efficient because it
can grow above the boiling point of ethanol hence facilitating the recovery of product.

8. Biodiesel

9. Biodiesel
• Biodiesel is a form of diesel fuel derived from plants or
animals and consisting of long-chain fatty acid esters.
• It is typically made by chemically reacting lipids such as
animal fat, soybean oil, or some other vegetable oil
with an alcohol, producing a methyl, ethyl or propyl
ester.
• This is used in blending with the petroleum or in its
pure form in diesel engines.
• The pure form is known as B100 or neat biodiesel and the most common blend is B5 and B20 which have 5% and 20%
of diesel respectively in the blend.
• Cold regions prefer B5 and B20.

10. Formation of Biodiesel
• Biodiesel is formed through the chemical reactions of trans esterification and esterification.
• This involves vegetable or animal fats and oils being reacted with short-chain alcohols (typically methanol or
ethanol).

11. Biobutanol
• Biobutanol is a four-carbon alcohol produced by the fermentation of
biomass. It has a long hydrocarbon chain which renders it non-polar.
• Its properties are similar to that of gasoline. It can be blended with
gasoline in concentrations up to 11.5%.
• Energy per unit volume of biobutanol is almost 1.5 times that of ethanol.
• Biobutanol can potentially be directly used in standard gasoline engines
with no modification!
• Feedstock are required for production, although non-food feedstock and
genetically modified bacteria and algae strains. Production costs are relatively
higher but this industry is in its
infancy and it needs to grow.

12. Methanol
• Methanol is an alternative biofuel.
• It is used in its pure form and with a blend as well.
• It is less expensive to produce than ethanol.
• Methanol is although cheaper to produce but it has less
energy density than ethanol.
• Hence it is preferred to be used in blend with ethanol +
petroleum.
• Primitively it was made by destructive distillation of wood.
• Presently it is synthesized by gasification where biomass is
converted into carbon monoxide, hydrogen and carbon dioxide
at high temperature. From this synthesis gas(CO + H2) is
extracted and than methanol is made from it.
• Through this method 75% pure methanol is generated.
• Currently it is usually used in race cars and sanitizers and no further use apparently has been made.

13. Conclusion
• A phase of change already hit us when humanity entered
the industrial revolution and brought up fossil fuel.
• Now earth is anticipating another phase change with
clean energy revolution which can only be brought up by
replacing the non-renewable source of energy with a
renewable source.
• Prevailing industries of biofuels are economically not that
good but with advances brought up by the upcoming
generation can make potential of biofuel limitless.
• Advancements in other natural renewable sources like
solar, wind, rain water, tidal and nuclear are also helping
to bring up the revolution.

14. Created by Meet Joshi
SEM V