GREEN CHEMISTRY-Bio-Diesel and Bio-Petrol: What You Will Need
GREEN CHEMISTRY-Bio-Diesel and Bio-Petrol: What You Will Need
GREEN CHEMISTRY-Bio-Diesel and Bio-Petrol: What You Will Need
Abstract
The Objective of this project is to study GREEN CHEMISTRY- Bio diesel and Bio petrol also study
extraction process of Bio diesel.
Green chemistry is the branch of chemistry concerned with developing processes and products to
reduce or eliminate hazardous substances. One of the goals of green chemistry is to prevent pollution
at its source, as opposed to dealing with pollution after it has occurred.
Introduction
Bio-diesel is an eco-friendly, alternative diesel fuel prepared from domestic renewable resources i.e.
vegetable oils (edible or non- edible oil) and animal fats. These natural oils and fats are made up
mainly of triglycerides. These triglycerides when rea w striking similarity to petroleum derived diesel
and are called “Bio-diesel”. As India is deficient in edible oils, non-edible oil may be material of choice
for producing bio diesel . For this purpose Jatropha curcas considered as most potential source for it.
Bio diesel is produced by transesterification of oil obtains from the plant.
Jatropha Curcas has been identified for India as the most suitable Tree Borne Oilseed (TBO) for
production of bio-diesel both in view of the non-edible oil available from it and its presence throughout
the country. The capacity of Jatropha Curcas to rehabilitate degraded or dry lands, from which the
poor mostly derive their sustenance, by improving land’s water retention capacity, makes it additionally
suitable for up-gradation of land resources. Presently, in some Indian villages, farmers are extracting
oil from Jatropha and after settling and decanting it they are mixing the filtered oil with diesel fuel.
Although, so far the farmers have not observed any damage to their machinery, yet this remains to be
tested and PCRA is working on it. The fact remains that this oil needs to be converted to bio-diesel
through a chemical reaction – trans-esterification. This reaction is relatively simple and does not
require any exotic material. IOC (R&D) has been using a laboratory scale plant of 100 kg/day capacity
for trans-esterification; designing of larger capacity plants is in the offing. These large plants are useful
for centralized production of bio-diesel. Production of bio-diesel in smaller plants of capacity e.g. 5 to
20 kg/day may also be started at decentralized level.
Procedure:
1. Measure 100 cm3 of vegetable oil into the 250 cm3 flask. Weigh the flask before and after to
determine the mass of oil you used.
2. Carefully add 15 cm3 of methanol.
3. Slowly add 1 cm3 of 50% potassium hydroxide.
4. Stir or swirl the mixture for 10 minutes.
5. Allow the mixture to stand until it separates into two layers.
6. Carefully remove the top layer (this is impure biodiesel) using a teat pipette.
7. Wash the product by shaking it with 10 cm3 of distilled or deionised water.
8. Allow the mixture to stand until it separates into two layers.
9. Carefully remove the top layer of biodiesel using a teat pipette.
10. Weigh the amount of biodiesel you have collected and compare it to the amount of vegetable oil
you started with.
Procedure:
1. Pour 125 cm3 of distilled water into the 250 cm3 flask and add 10 cm3 of universal indicator. Add
one drop of 0.1 mol dm-3 sodium hydroxide solution and gently swirl the flask so that the colour of the
solution is violet or at the most basic end of the universal indicator colour range.
2. Place 10 cm3 of this solution into the boiling tube.
3. Assemble the apparatus illustrated in Figure 1, attaching it to the filter pump with the vacuum tubing.
4. Place 2 cm3 of biodiesel onto a wad of mineral wool in the metal sample cup.
5. Turn on the water tap so the filter pump pulls air through the flask and ignite the biodiesel. Position
the funnel directly over the burning fuel, so as to capture the fumes from the burning fuel. Mark or note
the position of the tap handle so you can run the pump at the same flow rate later in the experiment.
6. Allow the experiment to run until the universal indicator turns yellow and time how long this takes.
7. Record what happens in the funnel and in the glass tube containing the second piece of mineral
wool.
8. Clean the apparatus, and repeat the experiment using 2 cm3 of kerosene (this is very similar to
diesel fuel).
3. Advantages of Jatropha
• Jatropha Curcas is a widely occurring variety of TBO
• It grows practically all over India under a variety of agro climatic conditions.
• Can be grown in arid zones (20 cm rainfall) as well as in higher rainfall zones and even on the land
with thin soil cover.
• Its plantation can be taken up as a quick yielding plant even in adverse land situations viz. degraded
and barren lands under forest and non-forest use, dry and drought prone areas, marginal lands, even
on alkaline soils and as agro-forestry crops.
• It grows as a tree up to the height of 3 – 5 mt.
• It is a good plantation for Eco-restoration in all types wasteland.
Trans-desertification Process
• It is the displacement of alcohol from an ester by another alcohol in a similar process to hydrolysis.
• Vegetable Oil i.e. the triglyceride can be easily trans-esterified in the presence of alkaline catalyst at
atmospheric pressure and at temperature of approximately 60 to 70oC with an excess of methanol.
• If 100 gm of vegetable oil is taken, 1 gm of the alkaline catalyst (Potassium Hydroxide), and 12 gm
of Methanol would be required
• As a first step, the alkaline catalyst is mixed with methanol and the mixture is stirred for half an hour
for its homogenization.
• This mixture is mixed with vegetable oil and the resultant mixture is made to pass through reflux
condensation at 65oC.
• The mixture at the end is allowed to settle.
• The lower layer will be of glycerin and it is drain off.
• The upper layer of bio-diesel (a methyl ester) is washed to remove entrained glycerin.
• The excess methanol recycled by distillation.
• This reaction works well with high quality oil. If the oil contains 1% Free Fatty Acid (FFA), then
difficulty arises because of soap formation. If FFA content is more than 2% the reaction becomes
unworkable.
• Methanol is inflammable and Potassium Hydroxide is caustic, hence proper and safe handling of
these chemicals are must.
References:
1. www.google.co.in
2. www.chemistry.org
3. www.ott.doe.gov/biofuels/environment.html
4. www.pcra.org