Waste to Energy

Urban India produces 55 million tones of municipal solid waste and 38 billion litres of sewage annually. Further, large amounts of waste are produced by industries.

Waste generation in India is growing at a very fast pace and is expected to rise rapidly in the future. This has mainly been due to industrialization, increase in living standards and urbanization. This waste needs to be contained.  The most profitable and feasible option is conversion of this waste to energy. Advancement in conversion technologies has made it easier to undergo this process thereby minimizing waste and utilizing its energy potential.

Waste to Energy India Scenario

According to the ministry of new and renewable energy (MNRE) 2010-11 annual report, there exists a potential of 3600 MW from urban and industrial waste. MNRE is actively promoting the generation of energy from waste by providing incentives and subsidies. Estimates from the Indian renewable energy development agency (IREDA) indicates that only 2% of waste-to-energy potential is being realized. MNRE targets 64 MW of Urban waste-to-energy plants and 780 MW of industrial waste-to-energy plants in the period 2011-2017.

Waste to Energy feedstocks

Feedstock for waste-to-energy can be broadly classified in the following categories:

  • Municipal solid waste (MSW)
  • Agricultural waste
    • Crop silage
    • Animal manure
  • Industrial waste
  • Gases from landfill
  • Construction and demolition debris

Waste to Energy Technologies

Waste-to-energy technologies convert waste material into forms of fuel that can be used to supply energy. Waste is treated and processed into various usable forms such as solid fuel, waste derived gas and heat/steam. Advanced waste-to-energy technologies can be used to produce biogas, syngas, liquid biofuels or pure hydrogen which can then be converted into electricity.

The primary categories of technology used for waste-to-energy conversion are as follows:

  • Physical Methods: Physical waste-to-energy technologies process waste mechanically to produce more suitable forms for use as fuel. These include producing:
    • refuse-derived fuel (RDF) or
    • solid recovered fuel (SRF)
  • Thermal Methods:  Thermal waste-to-energy technologies use heat or combustion to treat wastes.  Methods include the following:
    • Combustion
    • Pyrolysis
    • Thermal gasification
    • Plasma-arc gasification
  • Biological Methods: Biological waste-to-energy technologies use microbes or other organisms to produce fuels from waste. These include the following:
    • Fermentation
    • Methane capture/landfill gas/Anaerobic digestion

Waste to Energy Drivers

Most of the waste generated finds its way into land and water bodies causing severe pollution. The adverse effects of these can be mitigated by applying waste-to-energy technologies thereby reducing waste, generating energy and reducing environmental pollution. The key strategic drivers for waste-to-energy are:

  • Reduction in waste going to landfill
  • Reduction in pollution and greenhouse gas emissions
  • Reduced fossil fuel dependence
  • Eligibility for carbon credits and incentives

Waste to Energy Challenges

  • Lack of technological versatility
  • Waste gas cleanup technologies
  • Low conversion efficiencies
  • High capital costs
  • Complex regulatory hurdles

Various developments have been made in the recent years to overcome these challenges. Further advancements in waste-to energy technologies have also helped overcome the technological challenges to a great extent. We will discuss the challenges and its mitigation in detail in our future articles.

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2 comments

    1. Thank you for re-blogging.

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