THE rural areas of Bangladesh are mostly off grid from the main fuel source — natural gas. As a result, the rural people use wood/dry plants to meet their fuel need, a practice that further contributes to deforestation and emission of green-house-gases.
To solve this problem, a team of enthusiastic young engineers took the challenge to develop a user-friendly, low cost, light weight Portable Biogas Plant which will meet the cooking fuel requirement of a single family in rural areas. The PBP will work by digesting the organic wastes generated in the kitchen or other sources. Additionally, the slurry of the plant can be used as organic fertilizer and sold to farmers. People can collect biomass and sell it as ‘organic mass.’ This will increase the use of renewable energy, improve waste management, and minimise air pollution. It will, eventually, promote renewable energy not only to tackle climate change and increase usage of organic fertilizer, but also for better health.
At present, biogas plants in Bangladesh are not so popular due to fixed construction, poor design and high installation cost. Portable biogas plant is a new concept in this sector which is yet to be explored in Bangladesh. It will overcome all these shortcomings of the current biogas plants available in the market. The team developed the portable biogas plant with local materials and resources at a lower price.
After working for six months, the team was able to develop the plant and generate biogas from the portable biogas plant. The pilot project was set up at the Institute of Energy, University of Dhaka. The plant has a digester where wastes are digested in anaerobic condition. The digester, which is made of tarpaulin, has an inlet pipe for waste collection, an outlet pipe for taking out slurry and a gas outlet pipe. The digester with all its components can be packed in a single package and be transported to any remote areas. A user can unpack the components and set up the biogas plant very easily without the help of any external expert.
Biogas plants are in operation for a few decades in Bangladesh. Most of the plants are installed at domestic level and few are at industrial level. Bangladesh still has a huge prospect in exploring biogas plant technology in organic waste (municipal, sewage, dairy, poultry waste etc) treatment as well as generating valuable clean energy and organic fertilizer from wastes. Most of the plants in Bangladesh are fixed type which requires earth excavation and masonry. Installation and maintenance of fixed type biogas plants are critical as it involves external experts. But portable biogas plant is ‘plug and play’ type which does not require any external expert to install, operate and maintain. So, portable biogas plant could be a good approach to popularise biogas plants in Bangladesh.
Comparison of portable biogas plants with conventional biogas plants can show that it is easier to set up portable biogas plants as its user can unpack and attach the components in accordance with the instruction manual and set up the plant easily. A conventional biogas plant on the other hand needs external experts and masonry to set it up. Conventional biogas plant is also time-consuming. It needs several days to be installed depending on the digester size. The portable biogas plants are lightweight; it is easy to transport them to remote areas (especially hilly areas where road/rail transport is still unavailable). The digester of a conventional biogas plant is set up under the ground, which makes it difficult to maintain without the help of external experts. But portable biogas plants are installed on the ground which makes it easier to operate and maintain. The portable biogas plants eliminate the cost for earth excavation and masonry work. However, the operation cost of portable biogas plant in comparison to that of conventional biogas plants still remains undetermined.
Though biogas plant technology has significant prospects in Bangladesh, its use is still very limited. As I said earlier, we can convert wastes from municipal, dairy and poultry farms to valuable fuels and organic fertilizers. In this way, we can generate not only clean energy but also ensure a hygienic environment. Other countries are speeding up the use of renewable energy but we are lagging behind in our country. It is high time for the government to explore the possibility of turning wastes into resources, biogas and other renewables, to solve the scarcity of fuel in rural Bangladesh, and develop an appropriate policy, arrange research facilities and design localised solutions.
Niloy Das is a researcher at the Institute of Energy, University of Dhaka.