Blueflame Biogas Construction

We can biogas

Let me use a family of five as example. If the family owns 2 cows and have a little shamba. They have to prepare three meals per day. The family will use firewood, charcoal and kerosene and their total cost is app. Kenya shilling. 2000 per month. If they decide to invest in a Biogas plant with the size of 8m³, the following scenario will appear:

1. Buy the material like: sand, concrete, cement, stone, reinforcement iron, galvanized piping, some timber, PVC piping and the actual burner. The cost will be KES 100 000. Included here is the labour and Fundi salary. The family must dig the hole and prepare the foundation for the tank, the outlet and the inlet chamber.

2. When the plant is completed and accepted, we assume this to be saved within 2 – 4 years. In addition the shamba will produce more vegetables due to the better fertilizer.

How it works

Here is shown the principle of production by using animal dung. The process is called anaerobe, ie. (Process without oxygen) The bacteria will start the process of fermentation where it will be generated metan gas and carbon dioxide (CH₄ + CO₂) The sketch shows the principle for a plant.

During the process the pressure will increase, the level in the digester will be pressed down and the slurry will be pressed accordingly out through the outlet and are ready to be used as a very good fertilizer. When the gas is being used, the pressure falls and and the inside level in the digester will rise.

Its very important to feed the biogas plant every day, and use all the gas every day, so the slurry inside will be well mixed.

What about the size of the biogas digester and the amount of dung?

6 m³ You need abt. 40 kg (Two buckets) of dung from cow. From pig the needed amount is lesser, as the pig dung is more efficient

8 m³ This is the most common size if you have two cows and can collect all the droppings and the urine. This will give you abt. 70 kg and is sufficient for 3 – 6 hours with fire. 1 cow + 5 Pigs gives abt. 60 kg of dung, which is enough for 8 m³ size. In our hot climate the process is going faster. This is a big advantage.

12 m³ Here you need abt. 100 kg every day. 4 – 5 cows or abt. 8 – 12 Pigs.

38 m³ Here you need abt. 180 kg of dung. Give 5 – 10 hours of cooking. Alternative, 15 – 20 Pigs.

48 m³ Here you need abt. 3240 kg of dung. Gives 12 – 20 hours of cooking. Tanks of this size are normally constructed in institutions with large kitchen, as universities, schools, prisons, etc. Help to Self help have put up two no. of this size. Our estimate is that you can obtain this amount with a production of 100 – 120 slaughter pigs per year.

There are a lot of benefits with biogass, here are some:

1. It is produced from animal dung.

2. This dung becomes a much better fertilizer after the metan gas is eliminated.

3. It is totally clean and burns with no smoke.

4. You do not need firewood or charcoal.

5. You save the forest, which is vital.

6. You or your wife does not need to carry fire wood or buy it.

7. You lit the fire when you need it and turn it off when you do not need it.

8. You save your throat and your eyes health by avoiding smoke.

9. If you have enough gas you can use it for light.

10. And I want to continue to find many, many more applications for use.