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The need and prospect of promoting biogas in the country  

Shahiduzzaman Khan     | Published: September 28, 2019 22:03:56


Bangladesh remains far behind its neighbouring countries in developing biogas as an alternative to conventional fuel. It is apparent from the fact that the number of biogas plants is about 4.0 million in India, 8.0 million in China, 80,000 in Nepal and only about 10,000 in Bangladesh, according to a survey.

The consumers in the developing countries now prefer biogas as it is cost-effective and environment-friendly. Its widespread use can reduce dependency on natural gas and firewood, saving forests and increasing soil fertility. Poor people can save their hard earned money by using biogas as they need not purchase firewood for cooking or kerosene for lighting.

The Institute of Fuel Research and Development (IFRD) in Bangladesh undertook a plan to develop biogas technology about four decades ago. After a few years of research, the institute succeeded in developing a biogas technology in 1976. First they invented the floating dome biogas plant which could ensure gas supply for three to five years. Now the fixed dome model of biogas plant is used to ensure gas supply for at least 30 years.

Cattle dung, human excreta, poultry droppings and garbage are processed in the biogas plants under anaerobic conditions to produce biogas. Most of the biogas plants in the country were set up to process cattle dung. Seven or eight cows are required for a small plant.

The dung is mixed with water in equal ratio and stored in a tank.  After 10 to 12 days biogas is produced in the plant which is supplied to the ovens through plastic pipes. A family of five or six can easily cook their food and light lamps in their houses with such a plant.

About 70 per cent of the gas is methane which is better as fuel than firewood and the remaining gas is carbondioxide. The biogas supplied from the plant to the kitchen is used to run a two burner cooker where the gas burns with clean blue flame free of smoke or ash, much the same way a Dhaka city household burns Titas gas.

Installation of biogas plants started in 1996 under the Biogas Pilot Plant Project of the IFRD under the Bangladesh Council for Scientific and Industrial Research (BCSIR). The cost of installation of a biogas plant with a production capacity of 100 cubic feet gas daily was estimated at Tk 14,000.

A plant with production capacity of 100 cft is sufficient for daily cooking of a family consisting of 7 to 10 members. Besides cooking, light, fan, radio and television can also be operated with biogas. For the operation of a plant 60 to 70 kilograms of cow-dung or 40 to 50 kilograms of excreta of poultry birds are required.

In spite of being insignificant in volume, availability of biogas to a large number of rural people and remote areas makes the technology very suitable and effective. There is no denying that commercially produced pipeline natural gas plays and will continue to play vital role in industrialisation of the country, but such gas doesn't have the chance of reaching the remote village households any time soon. From this consideration, there is no alternative to biogas for millions of villagers.

Natural gas produced in the country is not enough for meeting the total demand. Besides, Bangladesh is also importing huge amount of crude oil and petroleum products every year. These are referred to as commercial energy and provide 35 per cent of the total energy consumed in the country. These commercial energies are mainly used in urban based industries to generate electricity, to run industrial and commercial units and to supply domestic households in major cities and towns.

Ironically, these commercial energies are mostly out of bound of the vast majority of the rural people. So where does the nation's energy balance leave the vast majority of the rural population? It is the biomass energy source that is available to them and it consists of fuel wood, leaves, agricultural residues, cow dung and other organic wastes. These are defined as non-commercial energy and actually provide for the remaining 65 per cent of the total energy consumed in the country.

Gas supply to the vast multitude of the rural people is practically impossible for two reasons. Firstly, it is not possible to quickly build gas pipeline infrastructure to connect thousands of villages throughout the country, and secondly, even if that were possible, rural population would not have the purchasing power to use pipeline gas in their households. Such a situation leaves the rural population reliant on traditional biomass sources for household supply of energy.

This is, however, not only a case with Bangladesh alone, but many other developing nations like India, Pakistan, Nepal, Sri Lanka, Thailand and China. Over the last few decades, there have been renewed interests and initiatives by many developing countries to innovate new and improved biomass energy technologies whereby the biomass energy sources can be used more efficiently and managed more scientifically.

The most popular and widely used of these technologies has been the biogas technology in which biomass (cow dung, poultry dropping, agricultural residue etc) is converted into biogas.

 The Local Government Engineering Department (LGED) of the ministry of LGRD and Cooperatives undertook a large project to promote biogas across the country. Though such projects have huge potential to upgrade the social and economic status and standard of living of rural population, there is neither enough manpower nor financial support to meet the total countrywide demand at the moment. There is a lack of understanding as well as commitment on part of the high-ups in the administration about this kind of micro level project.

The government needs to undertake a crash programme to promote biogas throughout the country on a large scale. As the country's forest and hydrocarbon resources are dwindling, biogas can be the best energy option for the vast multitude of rural population.                       

szkhan@dhaka.net

 

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