RENEWABLE ENERGY REVIEW: CASE STUDY- BIOMASS COOKING STOVE

22nd of February 2018, I was at a small town in the interior parts of Oyo state Nigera to see my grandparents. As usual, grandma made the move to entertain us and decided to make us a yam flour meal popularly known as Amala. She picked the pieces of firewood from the stack in the outdoor kitchen and arranged them in between the three big stones arranged at the fireplace. Few minutes after she lit the fire, the smoke ensuing from the fire place found its way to where we were sited discussing the situation of the country. As soon as we noticed the disturbance from the smoke, my mind went quickly to the post I made a day before that about the biomass and I knew that biomass finds application on the use for cooking but I knew quite a little. But hey! One of my colleagues in school is working on the biomass cooking stove- the very solution to the problem we encountered at granny’s.

As soon as I got back to school, I decided to do some questioning and research work concerning the biomass cooking stove and thus this post.

Biomass cooking stove

In my previous post, I was able to highlight biomass as a source of renewable energy and how it can be converted into other forms of energy. In times past, the traditional sources of heat energy for cooking purposes have predominantly been firewood (just like for granny) and coal. This method is common for people living in the developing countries and is usually brought about by the open fire method where the fire is usually set up by three or more stones surrounding the fire.

These forms of fire are commonly called the “three stone” fires. One characteristic of these method of cooking with wood is that it is very simple and easy to set up and relatively free. But the disadvantages of these set ups are greater than its advantages. The efficiency of the fuel is relatively low as they are about 5 to 10% efficient and the probability of excessive smoke generation is high which could cause health problems. The efforts of technology has been geared to improve the mechanism of cooking to suit the traditional requirements and also ensure affordability and conformity to the fuel required to be used. Also, the technology is geared towards reducing the pollution by smoke to reduce the health problems that may occur.

Biomass briquettes prepared for the stove

BIOMASS FOR COOKING

One of the common uses of biomass is for cooking and the predominant source wood while other sources are saw dust, coal, crop residues and animal dung. As stated above, the major challenge of using these sources of biomass is the efficiency of the method adopted and smoke disturbance. An area of great concern is the cause of health issues due to the inhalation of this smoke. The health effects brought about by this disadvantage include lung and eye ailments and even birth defects.
Use of biomass for cooking can also contribute to the deforestation and erosion rates in the locality.

The use of biomass for cooking cannot be stopped but the medium of use can be improved to eliminate these undesirable problems. Read more about biomass in my article here

BIOMASS COOKING STOVE

As stated earlier, improvements have been made to introduce a cooking stove that would eliminate the disadvantages of the three stone fire and ensure efficient energy (heat) transfer to the body to be heated (pot). A variety of designs have been introduced for improved stove geometry and pattern. Stoves such as the brick and mortar stove, prefab stoves, baker stoves etc. are quite known.

Using the stove

STOVE DESCRIPTION

The biomass cooking stove in question has the following parts with their respective functions:

• Reactor or housing: The housing is fabricated with fiber, glass wool is used to insulate the wall of the combustion chamber. It houses two chambers, the upper one is combustion chamber and lower is ash collection/ flue chamber.
• The Flue Chamber: Air circulation is important in order to keep the fire burning in the combustion unit. The draught is obtained in the stove with the help of the connection between the chimney, the flue chamber and combustion unit. The combustion units and the chimney pipe are mounted on the chamber. The flue chamber consists of adjustable air opening from both the side wall of stove for secondary air circulation.
• Grate: The grate is a metal frame for holding fuel wood, kept over the flue chamber.
• The Combustion Chamber: The combustion chamber is where fuel wood is burnt and heat is generated. It is mounted on the lower chamber, in which adjustable air openings have been provided from both side walls of stove for secondary air circulation and ash collection. The combustion chamber consists of the fire-box, and pot holes, circular grates and chimney.
• Chimney Pipe: The chimney pipe is at the center of the rear side. The height of the chimney can be adjusted according to the height of the room.
  The stove generally has a robust design which is intended to conform to rugged operating conditions for optimal performance. The stove basically operates in the normal format; the fuel is supplied to the combustion chamber and fire is introduced. The pot is placed directly on top the stove and the smoke is dispersed via the chimney.

ADVANTAGES OF USING THE BIOMASS COOKING STOVE

The biomass cook stove has the following obvious advantage which span from the advantages of using biomass itself to the advantages it has over the traditional fire place. They include;

• biomass cooking stoves are more efficient in terms of fuel economy and energy transfer
• they are relatively safer to use as they do not cause indoor pollution
• they reduce the use of biomass by up to 60 percent
• using biomass cooking stoves reduce cooking cycle times
• uses renewable energy and thus is eco friendly
• they come in a wide range of varieties for different types of biomass compositions

CONCLUSION

I am currently making plans to secure a biomass cooking stove for my grandma so as to ease her efforts in meal preparation and reduce the health risks that they are exposed to.
Technology always finds a way to provide answers to our problems only if we look inwards and think. Renewable is energy is the best form of energy as bit has numerous benefits which are obvious. However, one should note the best method of application of the resources available and the right methods of harnessing the resource.

RENEWABLE ENERGY IS LIFE

References

what is biomass

biomass cook stove

advantages of biomass cooking stove

pros and cons of biomass cooking stoves

All pictures taken by me.