For self-sustaining combustion, there should be a heat content of at least 2500 kcal/kg (about 5000 Btu/lb). Usually below 1500 kcal/kg, it is not recommended for combustion. Indian MSW is infamous for its low heat content (770 to 1000 kcal/kg, on dry basis, sometimes as low as 600 kcal/kg), high moisture content (30 to 55 % by weight) and high inert contents (30 to 50 % by weight). It is a fact that Indian MSW is not directly suitable for incineration. Waste preparation is a must for incinerating Indian MSW. Waste should be dried; inerts removed and heat content improved to about 2500 kcal/kg.
In order to determine whether a thermal processing project is a feasible waste management alternative for any city, the following questions should be addressed:
- Is source-segregation practiced in the target area?
- Is the thermochemical technology approved by the MNRE and the CPCB?
- Is there a buyer for the energy (electricity/CHP) produced by the energy recovery facility?
- Is there strong political and public support for a WTE facility?
- Are there enough funds to establish state-of-the-art small modular gasification / pyrolysis plant?
Elements of successful Advanced Thermal WTE Project
- Waste segregation
- Waste receiving and storage capability
- Waste preparation plant
- Gasification/pyrolysis process
- Syngas treatment process
- CHP / Power generation