Chemistry and energy of the future
Step 1 - Activities
Production and examination of bio-diesel in domestic conditions
1.1. Required materials (fig.1.):
- Vegetable oil (or waste cooking oil from the kitchen*);
- Methyl alcohol (methanol) CH3OH (density at 20ºС - 0,790 – 0,793 g/cm3 );
- Sodium base NaOH (98,5 %).
Weight ratio “ oil : methanol” = 5:1. The mass of the sodium base is 0.5 % of the total oil mass.
1.2. Required apparatuses (fig.1.):
heater; thermometer; measuring vessel; heat-resistant vessel of 1 l capacity; glass jar with a cap; kitchen funnel; kitchen scale; gloves; goggles; two empty plastic bottles of 1litre capacity.
fig. 1.
1.3. Procedures:
Step 1: Ingredients preparing. Pour ½ l vegetable oil or filtered waste cooking oil in the heat resistant vessel (fig.2).
fig. 2.
Step 2: Metoxide preparing. Weigh 2.5 gr. of sodium base on the kitchen scale (fig.3). After that measure 100 cm3 methanol (fig.4)
fig. 3.
fig. 4.
Methanol is poured in the glass jar and the sodium base is added afterwards (fig.5); the mixture is jerked intensively until the base is completely dissolved in the methanol (Sodium methoxide is obtained)(fig.6).
fig. 5.
fig. 6.
Step 3: Mixing of ingredients. Vegetable oil is heated on the heater until it reaches 60°С and then the solution of sodium methoxide is added (fig.7, fig.8).
fig. 7.
fig. 8.
The mixture is jerked several times in the next 60 min (fig.9) and is leaved at rest for a period of 24 hours (fig.10).
fig. 9.
fig. 10.
fig. 11.
fig. 12.
Step 4: Separation of biodiesel. After the process is over, the mixture is separated into two distinct layers: upper layer – bio-diesel, lower layer – glycerol. The lower layer (glycerol) is carefully poured out into another vessel (fig. 12).
fig. 13.
Step 5: Washing of biodiesel. The remaining upper layer (biodiesel) is washed several times with a quantity of water to remove the remnants of glycerol. After each washing the mixture is allowed to separate into layers and the lower layer is then removed (fig. 13).
Step 6: Drying of biodiesel. The bio-diesel obtained in this way is left in an open vessel for the purpose of removing the remnant water (drying).
Fig 14 shows ready biodiesel obtained from sunflower oil.
fig. 14.
