Turning Agricultural Waste into Fuel
In rural Pakistan, most cooking places are fueled with dried cow dung or wood. These fires develop a lot of smoke. This is a serious health threat, especially when the fires are held in poorly ventilated rooms. It is often overlooked that respiratory diseases are one of the greatest health risks to infants under the age of 5 (1).
Using wood as a cooking fuel adds to the progressing process of deforestation. Alternative fuels such as gas are mostly too expensive for the poorer population.
A way to counter this problem was developed by Amy Smith and the D-Lab Institute at MIT. The idea is to turn agricultural wastes into charcoal briquettes. Coal burns at a higher heat and emits less smoke than wood or cow dung. At the same time coal is easy to transport and to store. All that is needed for this process is a kiln made out of a slightly modified steal drum.
This technology is very simple and needs little initial investment. It is especially adequate for small to medium-sized farms as it can easily be scaled. The charcoal briquettes can be sold in the city with the other agricultural commodities.
Our Plans
We are starting this project with a test of the carbonization process in a village near Sargodha, Punjab. The main objective is to adapt the process to the local environment and to gather experience for further project implementation.
In a next step, farmers and other interested persons are invited to participate in a demonstration of the process. Afterwards these charcoal briquettes are used to cook a meal.
To realize this project, we work together with LivingEducation who consult and support the implementation. We want to
- offer an additional source of income for farmers
- work against air pollution and subsequent illnesses
- decrease the rate of deforestation
The Process of Carbonization
For a few years now, the amount of corn planted in Pakistan is increasing (2). The cobs, which remain when the corn is removed, are unusable and thus waste. However, their internal structure makes them ideal for this carbonization process.
The kiln is constructed from a slightly modified steel barrel. The only adjustments needed are to remove the top and put several holes in the bottom. A steal lid helps to close the drum for carbonization.
To allow the necessary air flow through the holes at the bottom, the drum is placed on three brick stones. Then the agricultural wastes are put into the kiln and ignited. Once the drum reaches the necessary temperature, the kiln is removed from the stones and sealed. The result is partial oxidation which turns the dried cobs into charcoal.
Generally all fibrous farming wastes such as crushed sugarcanes and peanut shells can be used for this process. However, they turn into charcoal fragments and dust instead of briquettes. Before being ready to use, they have to be compressed into briquettes. Corn cobs leave the kiln as ready-to-use briquettes.
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This technology was developed by Dr. Amy Smith and the D-Lab institute at MIT. It was originally designed for the rural population of Haiti, providing them with a clean, affordable and sustainable fuel. You can find the information about the project in Haiti here.
(1) WHO - Mortality Country Fact Sheet: Pakistan http://www.who.int/whosis/mort/profiles/mort_emro_pak_pakistan.pdf
(2)
Pakistan’s Crop Sector: An Economic Evaluation
http://www.usa.edu.pk/Web/Publications/PDF/PakistansCropSector.pdf?m=8
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Sugar production in rural Punjab, Pakistan. |