Bio-fuels practical.

Biofuels are solids, liquids and gases made from dead biological materials that can be burnt for energy. The burning of these fuels does release CO2 into the atmosphere. However,as they release CO2 that they have previously absorbed from the atmosphere, they are considered to be carbon neutral. Biofuels can be produced from plants or biological waste. Biological waste can be burnt or acted on by bacteria, crops can be specifically grown to produce biofuels such as ethanol. The most common fuel crops produce either ethanol, as in the case of corn and sugar, or biodiesel, which is used primarily for transport. During this practical we will produce biodiesel from vegetable oil.

-250mL of oil;                                     
-100mL beaker
-1.4g potassium hydroxide (KOH);   
-300mL conical flask;               
-55mL methanol(caution methanol is flammable and toxic);                                          
-stirring rod
-retort stand


-electronic balance;               
-heatproof gloves;

-separating funnel, as shown on the right;
- rubber stopper .


Step1 Add 55 mL of methanol to a 100 ml beaker and place the beaker on a hotplate.

Step 2 Weigh 1.4 grams of KOH and place it in the beaker with methanol. Place the beaker on the hot plate. Stir until the KOH is dissolved. Keep the temperature to around 50oC.


Step 3 Place 250mL of vegetable oil in a 300mL flask and heat on the hotplate to about 50oC.


Step 4 Pour the methanol with KOH dissolved into the oil.


Step 5 Stopper the flask with the thermometer as shown on the right and heat over a hotplate at between 55oC and 60oC for 15 minutes.
Remove the flask from the hotplate to maintain the temperature. Stir frequently as shown. You will notice the colour of the methanol, floating on the surface, steadily change colour.



When the reaction is complete the methanol layer disappears as shown on the right.