Solid waste is one of the important challenges human civilization deals with today, while environmentalists consider that as one of the significant resources. With rapid increase in population and urbanization, improper disposal and poor management of solid waste generated in Bangladesh (16,380 tons per day) is severely worsening the environmental condition. Particularly, organic kitchen wastes account for about 70% of the solid waste generation in the country. Bangladesh is a highly populated country (163 million) with density of population is1278 per km2 in 2018.Consequently, unplanned urbanization, substantial growth of slums and overexploitation of resources generate a significant amount of waste in Bangladeshwhere establishment of sustainable solid waste management practice is obviously needed.In Bangladesh, solid waste is generally disposed of as open dumping in surrounding areas like streets, river banks, fields, etc. which results in a number of adverse environmental and health impacts. We would be able to minimize these adverse effects arising out of unscientific disposal of solid waste if we can properly manage and use the solid waste as a resource. Recovery of energy from solid waste can be of one of the important aspects of sustainable solid waste management and eco-friendly society. Biogas from biodegradable solid wastes such as food waste, cattle and poultry manure, agricultural waste, human waste etc.is an effective way to recover energy from solid waste. Biogas, rich in methane, has the same characteristics as the natural gas with no adverse environmental impacts which has drawn the attention of many researchers and is the most used form of renewable energy globally bigger than hydr.
Bangladesh has recognized the energy value of biogas from cattle manureat some extent, especially for the rural people who use biogas for cooking. They particularly depend on biogas for such daily purposes due to lack of conventional energy supply facilitiesbutmajority of them are unconscious about the valuable use and environmental benefits of using waste derived biogas. Biogas can be used as fuel for vehicles and also used to produce heat and electricity as well without depletingnon-renewable resources of the Earth.The biogas process also gives bio-fertilizer as byproduct which can replace the use of harmfulchemical fertilizers while optimizing agricultural production. However, we are not giving importance on solid waste, whereas we are treating it as a burden or problem instead of potential energy resource!
In other sides, European countries and cities have set up biogas as vehicle fuel projects. It is the case of Sweden, France, Switzerland, Iceland and Italy who started in the 90’s for country’s public transportation. In the United Kingdom, biogas is estimated to have the potential to replace around 17% of vehicle fuel. All city buses at Linkoping city in Sweden are running on biogas. From the technological perspective, biogas technologies are already fully developed and are being continually improved. Usually anaerobic digestion process is used for biogas production, whereas CHP (Combined Heat and Power) technology is used to produce electricity and heat simultaneously from solid waste. CHP technology is proposed and supported by the European Union which is already saving 35 MTOE (Million Tons of Oil Equivalent) per year, providing 11% of Europe’s electricity and heat, as a low carbon and high efficiency solution for electricity and heat supply with tens of thousands of installations across Europe.
Although the cost of waste derived fuel production is quite expensive compared to conventional diesel fuel, the real picture is quite different thatfossil fuel burning is responsible for more than generating electricity and running vehicles. The potential cost for biodiesel, one kind of waste derived fuels, is in the range of US$1.6 to 23.96 per liter compared to diesel fuel which costs US$0.71 to 0.91 per liter. But burning fossil fuels emits a number of air pollutants that are harmful to both the environment and public health. Each year pollution from fossil fuel burning takes an estimated cost more than US$100 billion annually in health expenditure.An arguably more realistic estimate of US$100 per ton of CO2 would bring global fossil fuel subsidies to over US$4 trillion per year, with US$3.2 trillion due to climate change.On the other hand, biofuels usually cause low or no pollution to the environment and the cost of production can also be reduced by reducing the cost of waste processing techniques and production technologies and also conducting cutting-edge research on this sector.
The socio-political perspective of Bangladesh indicates that solid waste has a huge potentiality to produce biogas and biofuels which can meet the energy demand of the country. The Government of Bangladesh should explore the feasibility of such potential energy source by starting a pilot project where household solid wastes would be used to produce bioenergy for cooking, electricity, vehicle fuel and fertilizer.Success of this project would ultimately encourage the production and use of solid waste derived energy at household and community levels of Bangladesh.
Once the large-scale production and use of energy from solid waste is ensured, dependency on fossil fuel-based energy sources will be decreased. Relying on such bioenergy source will not only help to sustain our limited non-renewable energy sources, but also to provide a pollution free and green environment for our future generation. The Vision 2021 of the Government of Bangladeshpromises a prosperous and equitable middle-income country by its golden jubilee of independence. Energy security is one of the critical elements and challenges for achieving such milestone. So,it is time to invest more in renewable energy such as biogas from solid waste rather than in fossil fuelbased energy that can be beneficial from the context ofenvironment, energyand waste management.
Ommay Hany Ria
B. Sc. (Hons.), Student
Department of Environmental Science and Resource Management MawlanaBhashani Science and Technology University (MBSTU) Tangail-1902, Bangladesh
Sowmik Das Sowmya
B. Sc. (Hons.), Student
Department of Environmental Science and Resource Management
MawlanaBhashani Science and Technology University (MBSTU) Tangail-1902, Bangladesh