Polycrack Technology

  • On 23rd January, 2020, Indian Railways commissioned the country's first governmental waste to energy plant in Mancheswar Carriage Repair Workshop at Bhubaneswar, Odisha under the East Coast Railway zone.
  • The plant will use Polycrack technology to process the scrap and convert waste into energy to produce light diesel oil in 24 hours.
  • This is the first such plant of the Indian Railways network and the third such plant across the country.
  • The first plant was a small one with a capacity of 50 kg a day set up by Infosys at Bangalore in 2011. The second came up at Moti Bagh in Delhi in 2014 and the third one was set up at Hindalco in 2019 with 50 kg capacity per batch.

Need

  • A big chunk of non-ferrous scrap is generated in Indian Railways workshops for which there is no efficient method of disposal and treatment. As a result, the scrap is sent to landfills, which is environmentally hazardous as its treatment is difficult.

What is Polycrack Technology?

  • Polycrack technology, the first patented heterogenous catalytic process, converts non-ferrous scraps into hydrocarbon liquid fuels, gas, carbon and water and doesn’t require pre-segregation of waste for their processing.

Waste Used

  • All types of plastic
  • Petroleum sludge
  • Un-segregated MSW (Municipal Solid Waste) with moisture up to 50 percent,
  • e-waste, automobile fluff
  • Organic waste including bamboo, garden waste, jatropha fruit and palm bunch
  • Sludge from Edible Oil Industry
  • De-oiled Cake from Edible Oil Industry

Features

  • Polycrack’s strength includes not requiring pre-segregation of waste, allowing waste as collected to be directly used. With a high moisture tolerance, drying of waste is not required.
  • The process is a closed cycle system and does not release dangerous pollutants into the atmosphere.
  • All constituents are converted into valuable energy thereby making it Zero Discharge Process.
  • The flammable, non-condensed gases are reused to supply the entire system with energy. The only emission comes from the combustion of gaseous fuels.
  • Gas generated in the process is re-used to provide energy to the system thereby making it self-reliant of its energy requirement and also bring down the operating cost.

Advantages

  • Fully automated system requires minimum man power.
  • Low capital cost and low operating cost.
  • Operates at around 450 degrees, making it a low temperature process when compared with other options.
  • Excellent air quality surrounding the plant.
  • Biological decomposition is not allowed as the Waste is treated as it is received.
  • The foot print of the WTE plant is small hence the area required for installing the plant is less when compared with conventional method of processing.
  • There is no atmospheric emission during the process unlike other conventional methods except for combustion gases which have pollutants less than the prescribed norms the world over.
  • Safe and efficient system with built-in safety features enables even an unskilled user to operate the machine with ease.

Waste to Energy

  • Waste-to-Energy (WTE) refers to a variety of treatment technologies that convert waste to electricity, heat, fuel, or other usable materials, as well as a range of residues including fly ash, sludge, slag, boiler ash, wastewater and emissions, including greenhouse gases.
  • It provides a safe, technologically advanced means of waste disposal that reduces greenhouse gases, generates clean energy and recycles metal.
  • It offers recovery of energy by conversion of non-recyclable materials through various processes including thermal and non-thermal technologies:

Thermal Technologies

  • Gasification
  • Pyrolysis
  • Thermal Depolymerization
  • PGP (Plasma Arc Gasification)

Non-thermal Technologies

  • Anaerobic Digestion
  • Mechanical biological treatment(MBT)
  • MBT + Anaerobic digestion
  • Ethanol Production
  • MBT to Refuse Derived Fuel

Benefits

  • Production and Use of Energy: Electricity and heat can be generated from waste, which provide an alternative and more environment-friendly source of energy.
  • Alternative to Fossil Fuels: Waste-to-energy is one of the most robust and effective alternative energy options to reduce CO2 emissions and replace fossil fuels.
  • Reduction of Waste Going to Landfill: Waste that would have normally gone to landfills is diverted to an energy processing unit thereby saving valuable land.
  • Help in Climate Change Mitigation: WTE is widely recognized as a technology that can help mitigate climate change. WTE facilities are the only form of energy generation that actually reduces greenhouse gases. When waste is delivered to a WTE facility, the methane that would have been generated if it were sent to a landfill is avoided.
  • Domestic Production of Energy: Plenty of waste is generated locally and hence there is no requirement of transportation of materials or this process from far out.
  • Benefit to Local Community and Economy: As waste to energy plants are generally setup locally it creates jobs, the local community benefits and materials are sourced locally.

Challenges

  • High Operating Cost: Effective waste management is expensive, often comprising 20 per cent to 50 % of municipal budgets.Despite all the subsidies, the electricity produced from WTE plants is the most expensive. Compared to Rs 3-4 per kWh from coal and solar plants, WTE plants sell electricity at about Rs 7/kWh.
  • Sustainability Issue: Most wastes sent to the WTE plants are un-segregated which impacts the power generation by the plant and leads to pollutants. Moreover, the leftover burnt material is not suitable for brick making, which then has to be disposed off in landfills, further increasing pollution.
  • Feasibility Issue: WTE plants do not get many buyers for the power they generate due to cheaper alternatives being available and high maintenance costs. This is because of a high capital cost, high operation & management expenses, low calorific value of the fuel used and the additional fuel used to burn the waste.
  • Health Issue: Because these plants have to handle a vast quantity of mixed waste, the housekeeping is extremely challenging leading to a lot of odour and visual pollution.

Source : Civil Services Chronicle Online, January, 2020