Bangladesh has set a target to generate 10% of the country’s electricity from the renewable sources by 2021. As per BPDB statistics, Bangladesh Govt has a plan to generate around a total of 18838 MW electricity by 2021 from which 1883 MW from the renewable sources.
Bangladesh Government is now prioritizing the Solar power projects as the renewable energy projects in the country. But till now, only IDCOL’s off grid home solar system (221 MW by 2021) is the only success in the renewable energy sector, although Bangladesh Government has signed contract for lots of grid connected Solar Power Projects as per build own operate basis. Most of them have no chance to get into operation or very few will be implemented by reduced capacity.
The main barrier to implement these solar IPP projects are to manage huge amounts of land and build investor’s reliability. There are so many options available in the renewable energy such as Solar, Wind, Geothermal, Hydro, Municipal waste, etc among which solar power projects need huge space (3.5-4 acres per MW). Bangladesh is a small densely populated country and the proper usage of every inch of land is vital. So, for only generating power during day time, it is not feasible to engage huge amount of land for a long period. On the other hand, Geothermal, Hydro and Wind are lesser feasible options in Bangladesh due to geographical condition. Comparing all these,
Municipal Waste to Energy is the most viable option for Bangladesh to fulfil the 10% target of generating electricity from the renewable source. Now a days, average 3 MWH electricity can be generated from 100 tonnes per day of municipal waste. So, optimistically, around 2700 MWH electricity could be generated from the municipal waste of the whole country if collected properly.
Moreover, MSW to electricity project brings enormous benefits to the nation in the health sector by reducing the water borne disease and controlling pollution. Bangladesh is far behind in the country’s waste management, especially the solid waste management in Dhaka & other major cities, comparing to the neighbouring countries. The estimated population of Bangladesh is around 168 million by 2019. Dhaka is one of the most densely populated Mega City in the world with a population of around 18.5 million estimated in 2016. Population of Dhaka city increases 5-6% per annum and the trend of growth is likely to be maintained in the foreseeable future. The infrastructure of Dhaka has not been built ensuring proper civic, social, health & environmental facilities. Dhaka also has the highest population density of 45000 per sq.km in the world cities ranking, whereas Mumbai is second with 30000 per sq.km. Dhaka also became 2nd lowest among 160 cities in the world as per the living standard.
Municipal Solid Waste (MSW) in Dhaka and other cities pose serious problem having adverse effects on environment and health of the citizens. The amount of waste is expected to grow in the future as the waste increases with the rise of city population and living standard. The waste generation rate generally increases as the GDP increases. The average per capita solid waste generation in India is 370-500 grams/day as compared to 2,200 grams in Denmark, 2,000 grams in US and 700 grams in China. The per capita solid waste generation in Bangladesh and Dhaka city can be calculated as 500 gm/day. The approximated daily municipal waste generation in Dhaka is around 9500 tonnes and 84000 tonnes in Bangladesh in 2016. Dhaka South City Corporation (DSCC) collects and manages 2000-2200 tonnes per day MSW at Matuail land fill and Dhaka North City Corporation (DNCC) collects and manages 1600-1800 tonnes per day at Amin Bazar land fill. There are around 10 other city corporations and 327 municipal corporations in the country also collect municipal solid waste every day and dump to their designated places. Municipal Solid waste causes serious health threats to the city dwellers if it is dumped or managed improperly. The following are the major problems associated with the unsafe MSW management:
Surface water pollution
Ground water pollution
Water logging due to blockage of drains
Produces toxic odours
Spreading water borne diseases i.e. Diarrhoea, Typhoid, Malaria, Hepatitis etc.
Increase chronic disorder (cancer) in human body
Increase the cost of potable water supply
Destroy natural ecosystem and aquatic ecology.
Present unhealthy population
MSW to Electricity Process Options: The composition of MSW in Bangladesh has very low heat content (3-6 MJ/kg) due to huge moisture (50-60%), about half of that in the developed countries and organic content (50-60%), which requires considerable additional energy to preprocess the MSW to prepare as feed stock for the conventional type of waste to energy technologies, such as Incineration, Plasma Pyrolysis or Gasification due to high moisture & organic
Based on prevailing conditions with respect to gradual growth of technology and quantity/quality of MSW, the possible new generation solution for Bangladesh is to generate biogas & electricity and compost from the MSW. The raw MSW will be passed through the vibrating screen and sorter conveyer belt to recover the recyclable material and later through Organic Liquifying press which separates the organic and in-organic properties. The bio-degradable organic wet portion will then
be sent to anaerobic digestion. The biogas thus generated would then be used to generate electricity by using gas generator. The solid residue generated from the biogas operation could be used as organic fertilizer (compost) after dehydration and the liquid portion will be collected as liquid fertilizer. The compost will further be processed to produce different crop based Organomineral fertilizer. The inorganic or non-biodegradable portion that obtained from the pressing process will be further processed by screening, manual, optical and magnetic separator. The residue will then be shredded and dried to obtain RDF (Refused derived fuel). The RDF will be used to generate electricity by Grate Incineration or Gasification based gas turbine. The process has substantial amount of by-product as ash (3-5%) which will have secondary demand in the cement manufacturing plant. The entire plant will be technically equipped for emission & waste management to meet national and international Environmental standards.
The following are the Process flow diagram of MSW management: Probable output from the MSW management for Dhaka city:
Total MSW to be treated: 9000 MT/day
Total Electricity Generation: 270 MWh
Organic fertilizer: 300000 MT/Year
Crop based balanced Fertilizer: 400000 MT/Year
Liquid Fertilizer: 160000 MT/Year
Recyclables as steel, glass, ceramic, plastic etc.: 270000 MT/day
Total Project Cost: 900 million Euro
Benefits: The Project has multiple objectives of generating electricity from a renewable source,
reduction of greenhouse gasses (GHG). The following will be the benefits from the MSW
management of Bangladesh:
• This new innovative idea will reduce the cost and space by replacing conventional landfill
• Generate huge income for the Govt.
• Can handle any type of MSW where the moisture content and organic portion is very high
which is not suitable for conventional W2Energy projects.
• Generate huge potential/useful by-product.
• Minimum end residue produced and little to no waste products.
• A sustainable solution for the MSW in the developing countries in monsoon climates.
• Prevent environment pollution and GHG emission.
• Present a clean & healthy city.
• Reduce water logging in the city
• Make waste into resources.
• Improve Health & Hygiene of the nation
Likely Financial Incentives for the project: MSW management project in general involves big investment and require frequent maintenance, generally may not be comparable to other projects in terms of revenue generation and internal rate of return. The general project breakeven period in this case is 9-10 years, so, in most cases financing organizations does not show much interest to inject finance on such slow income generating projects. Moreover, Bangladeshi MSW is mostly wet and organic in which the project breakeven period will be more. In such case, Bangladesh Government should provide subsidy or incentives to the project sponsor for implementing the
MSW to energy projects to make the project economically viable. All MSW to energy projects are subsidised by the government across the world. The project brings
huge benefits to the city and its population in many ways. In the long run government will be benefitted by preventing water borne diseases, environment pollution control and saving valuable land. Health sector improvement is the most significant from this project. The private investors would generally expect the following incentives from the Govt:
Reduction/waiver of customs duty on import of machinery
Tax and VAT exemption
Guarantee of payment by power purchase agreement with escalated electricity tariff.
Guarantee of foreign exchange remittance
Guarantee of convertibility of foreign exchange
Paying tipping fees to the investor to operate the plant.
Bangladesh Govt may support the project under viability gap financing (VGF)
Provide rent free lease of land.
Conclusion: Municipal Solid Waste management projects are considered as renewable energy project. MSW management for any city is a civic facility should be provided by the government to ensure better and healthy city life. MSW once not collected and managed in proper way, creates serious health hazards, spreads water borne diseases, pollutes air, surface & ground water ultimately presents an unhealthy population. Bangladesh is the most densely populated country in the world, so, proper MSW management is vital for Bangladesh. On the other hand, the quality of MSW in Bangladesh is not suitable for conventional waste to energy projects due to its high
moisture & organic matter presence, so, selection of appropriate technology for MSW management is also critical. Taking into consideration of the critical nature of MSW in Dhaka, the above proposed technology is proven to handle such moist & organic waste and process in a nonthermal way to generate energy and other essential by products.
Dr. Nasir Uddin Khan
Environment Management Specialist
Sidcup, Kent, United Kingdom