Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras

Technology Category/ Market

Technology:; Catalysts depolymerization process focusing on managing plastic waste at source; Industry: Environment Engineering, Applications: Waste management, Catalysts, Sensors;

Market: The global plastic waste management market is projected to grow at a CAGR of 3.40%  during 2023-2029.

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Problem Statement

  • In the present era, Plastic waste has become a major element in garbage and most of the plastic waste does not decompose naturally in garbage dumps and create toxic smoke after burning, which causes serious environmental problems, and need to be recycled.
  • In the patent or non patent literature survey, it is noted that pyrolysis process used to convert plastic waste into wax/oil product which is costlier process due to the use of costly commercial grade catalyst including other issues.
  • Hence, there is a need for improved solution.


  • The present invention describes an environmentally friendly catalytic depolymerization process for focusing on managing plastic waste at source.
  • The process comprising a few steps described hereinbelow:
  • First step explains about using a depolymerization technique at temperature in the range of 400 ℃ to 500 ℃ in a pyrolysis unit consisting of a pyrolysis chamber made of annular cylinders.
  • Said pyrolysis chamber is configured with annular cylinders to break down the long chain polymers into short chain branched alkanes and aromatics as fuel oil.
  • The annular cylinders of the pyrolysis unit provide the required space for uniform heating of plastics at the inside chamber using electrical energy.
  • The process further comprising using at least one waste material from various industries as catalyst material at the pyrolysis unit to maintain temperature uniformity and enhance fuel oil yield. (Refer FIG. 1)

Key Features/ Value Proposition

Technical Perspective:

  • The utilized waste generated from different process & manufacturing industries, comprises of waste graphite (forging industry), brake wire powder (automobile industry), foundry sand (foundries), furnace slag (iron and steel industries), pyrolyzed slag (pyrolysis plant), fly ash (thermal power plants), etc.
  • The waste material as catalyst facilitates not only increases the plastic polymer cracking but also reduces the operating cost of the plan in the long run.
  • The pyrolysis process was optimized based on the combination of temperature holding material, catalyst, different contact pattern (insitu, ex situ) of catalyst with waste plastic and its vapour plays a major role in the final product quality.
  • Metal doped zeolites, pyrolysis plant slag, spent catalysts from oil refining industries as catalysts for depolymerizing waste plastics in pyrolysis unit.

Industrial Perspective:

  • Cost-effective process.
  • The reusability of Plastic waste from industry used as raw material makes the invention eco-friendly.

Questions about this Technology?

Contact For Licensing

Research Lab

Prof. Indumathi M Nambi,

Department of Civil Engineering.


Intellectual Property

  • IITM IDF Ref. 1751

  • IN Patent No: 473578

Technology Readiness Level


 Proof of Concept ready, tested in lab.

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