The process, which involves waste for the production of energy, is named as waste-to-energy and Energy-from-waste. WtE is a process, which recovers energy from the waste materials. It is required to mention here that WtE is a process in which energy is gained through the process of combustion directly or sometimes fuel is produced from waste, which is the source for energy.
The most common source for WtE is “incineration” which means to burn organic waste to get energy. Incineration is not just conducted to recover energy rather it is most of time conducted to get rid off waste but it is banned in the countries with ODEC. Additionally, the ODEC countries only conduct WtE when they have plants following strict rules for emission. Therefore, today the plants to conduct incineration are much advanced as compared to older ones. The modern plants are capable for reducing the volume for given waste up to 95 to 96 percent. The compression reduction depends upon the composition and recovery degree of the waste materials.
The incineration becomes an issue because of emission of fine particles, metals of heavy configuration and acidic emission in form of gases. No doubt the emissions from incineration are in smaller quantities in modern plants but still they are if great concern. Some other concern for incineration are emission if poisonous fly ash and IBA (incinerator bottom ash). When discussed light was thrown over the destruction of valuable resources and it is said, “The incineration can affect the forthcoming recycling campaign”.
WtE technologies (other than incineration)
A number of technologies have emerged on the scene for WtE or EfW. These technologies are capable for recovering energy from waste materials. Most of these technologies come with the power to give out power that is more electric and yes, that from the same amount of fuel as is produced by the incineration. This increased capability is result of the deduction of ash from the extracted fuel resultantly, higher temperature produced from combustion. Some technologies however are capable for converting liquid fuel in to gas.
These technologies are as follows:
- Thermal Depolymerization
- PGP (Plasma Arc Gasification)
- Anaerobic Digestion
- Mechanical biological treatment
- MBT + Anaerobic digestion
- Ethanol Production
- MBT to Refuse Derived Fuel
Emission of Carbon dioxide
When wee speak about the WtE it must be known that almost every part, which has carbon in its make up, gets out from the bulk of the waste as Carbon dioxide CO2 and is taken to the environment. Solid waste from municipal has carbon dioxide in approximately 27 percent of its composition. Therefore treating 1 metric Tons of
Municipal solid waste would produce 1 metric Ton of Carbon dioxide.
When the waste is got to fill landfill then MSW in amount, 1 metric ton would produce 62 cubic meters of methane gas due to the decomposition conducted by anaerobic reactions. This gas produced comes with the double potential for playing its share for global warming as compared to one meter ton of carbon dioxide. In most of the countries around the globe, the gas is collected but still residue left away is handsome enough to contribute to global warming.