Biodiesel: Fuel For Next Generation

By:-Akshay Patil Roll no.57

QUICK RECAP

What is Biodiesel? Properties Advantages/Disadvantages Uses

Lubricating Properties Higher cetane number Calorific Value range 38-43 KJ/g Immiscible with water High Boiling point and Low vapor

pressure

METHODS

There are three basic methods of biodiesel (methyl ester) production from oils and fats. They are:1. Base(NaOH/KOH) catalyst trans-

esterification of the oil with methanol.2. Directed acid catalyzed esterification of

the oil with methanol.3. Conversion of the oil to fatty acids, and

then to methyl esters with acid catalysis

ECONOMICS

  Quantity

(Litre)

Rate/

litre

Cost

(Rs)

Revenu

e (Rs)

Oil 1321 4.30 5680.3  

Reagents 22.510 8.7243 196.38  

Methanol 211.36 60 12681.

6

 

Electricity

and Water

108.326 0.6711 72.69  

Filtration 1321 2.0133 2659.5

7

 

Purification 1191.58 2.684 3198.6

9

 

Labour 1000 4.28 4280  

Glycerine 471.614 4.69   2215.5

Total Cost = 26553.7

Taxes (18 %) = 4779.6Distribution (20 %) = 5310.74

Net Price = 36644.05

... Rate of Biodiesel per litre = = 36.64 Rs

TRANSESTERFICATION

Transesterification is the process of separating the fatty acids from their glycerol backbone to form fatty acid esters (FAE) and free glycerol.

COMPARISON WITH CONVENTIONAL DIESEL

EXPERIMENTAL WORK

PREPARATION OF BIODIESEL

For preparation of biodiesel in the lab alkali catalyzed “transesterification” is to be used.

Free fatty acids will increase the time required for heating vegetable oil. Oil which has been used for cooking will required more of the reactive agents and methanol than fresh oil.

The presence of too many free fatty acids will retard or stop the reaction, which produces biodiesel, so it is necessary to deduce the exact amount of alkali (sodium hydroxide) needed to neutralize the acids.

Adding too much or too little NaOH will make excessive amounts of soap as a by-product.

RAW MATERIALS

Vegetable oil: Diesel has a chain of 11-13 carbons and new vegetable oil has a chain of about 18 but wasted vegetable oil which is heated has chains of up to 32 carbons. To burn in an engine, the chain needs to be broken down to be similar in length to diesel.

NaOH : It is the catalyst for transesterification and works by cracking the vegetable oil molecules, splitting the triglyceride from the hydrocarbons and shortening the carbon chain

Isopropyl alcohol: It is used to dissolve waste cooking oil during determination of extra amount of alkali (NaOH) in titration.

Methanol: a little amount of methanol is necessary in order to get the highest yield. If 90% yield is obtain that means 90% fatty acids have been eliminated from the vegetable oil. Generally 15% to 20% methanol based upon the total weight of batch of oil is necessary.

EXPERIMENTAL PROCEDURE

1. TitrationWe plan to carry out titration to determine the amount of NaOH is required to neutralise the free fatty acid; the procedure is as follows:

Dissovle 1 gm NaOH in 1 litre of distilled water to make 0.1% (w/v) solution and fill this solution in pipette

In a small beaker dissolve 1 ml of waste vegetable oil in 10 ml of isopropyl alcohol.

Slowly increases the temperature by keeping this beaker in hot water bath for about 10 minutes on 300 C to dissolve the oil. Add 2 drops of phenolphthalein indicator into the beaker.

Titrate against 0.1% (w/v) NaOH solution. At the end point the color of the solution will turn pink.

Repeat the same procedure 3 times and obtain average titration reading. Using the average value for titrations determine the amount of NaOH

required to neutralize free fatty acid.

CALCULATION

Type of oil Average volume (ml) Weight of NaOH required (g)

WCO unfiltered 4.1 1.025WCO filtered 1.5 0.375Soy Oil 1.8 0.450Sunflower oil 0.8 0.200Rice Bran oil 2.2 0.550Sesame Oil 1.3 0.325Palm oil 1.6 0.400

Preparation of Biodiesel Heat 250ml of the oil at 60o C to remove

moisture content, by using heating mantle. Add NaOH into 160 ml of methanol and heat

separately. After 15 minutes mix both solutions in a beaker.

Add a magnetic needle to the mixture and place the mixture on the magnetic stirrer + hotplate and the set the temperature to 60o. Start the stirring (800-1000 rpm) and continue for about 25-30 minutes.

After 30 minutes transfer the mixture into a separating flask and shake thoroughly. Leave the mixture to settle for 24 hrs at room temperature to separate the glycerin and crude biodiesel. Collect the two fractions in two separate conical flasks.

To improve the quality of biodiesel add equal amount of water into the conical flask and shake thoroughly and leave the conical flask to settle. Decant the water out. This can be done twice if required.

COMPARISON OF DENSITY OF BIODIESEL

Types of Oils0.75

0.8

0.85

0.9

0.95

1 0.992

0.892 0.880.899

0.988

0.860.887

WCO (unfiltered) WCO (filtered) Soy oilSun flower oil Rice Bran oil SesamePalm oil

Den

sit

y (

kg

/m3

)

CURRENT RESEARCH

• There is ongoing research into finding more suitable crops and improving oil yield

• Biodiesel from Human Fecal matter with Ghana building its first plant

• US(largest diesel fuel user) developing biodiesel technologies for navy and military

• Ecofasa announced a new biofuel made from trash. Urban waste is treated by bacteria to produce fatty acids, which can be used to make biodiesel.

• Another approach involves the use of genetically modified microbes.

Thank You