Refuse Derived Fuel (RDF) is one of the options to extract energy from the combustible material in the waste. It is basically a method of pre-processing the waste in order to use it as a fuel in boilers. This technology involves various processes to improve physical and chemical properties of solid waste. Basically, RDF systems are used to recover recyclable materials and to separate MSW into combustible and non-combustible fractions.
The combustible material is called RDF and can be used in boilers. Typically the volume of waste is reduced to 20 to 30%. RDF has a higher calorific value when compared with that of MSW (more than 3 times of MSW).
Waste sorting includes primary and secondary trommel screens, which mechanically separate the dry fraction from the organic, magnetic and induction-type separators for metals recovery, a glass recovery system and a shredder.
Due to removal in fuel particle size and reduction in non-combustible material, RDF fuels are more homogeneous and easier to burn than the MSW feedstock. RDF has been successfully burned in a variety of stoker boilers or in bubbling and circulating fluidized bed combustion technology boilers.
Due to the homogeneous nature, it needs less excess air and hence works at better efficiency. Also, handling is easier since non-combustibles are already removed. They produce better quality of ash and ash disposal is less problematic. Specially designed fluidized-bed combustors produce fewer pollutants through the flue gas.
Emission characteristics of RDF are superior when compared to that of coal due to less NOX, SOX, CO and CO2. The advantage of the refuse-derived fuel plant type is relatively higher energy content of the RDF fuel.
The investment cost of RDF based power plants is higher when compared to that of biomass plants. Therefore tipping fee and CDM CER revenue are required in addition to the sale of electricity. Implementing such projects take more time than that of biomass power plants. Project developers should pay adequate attention to the preparatory works before implementing these projects.
Although these plants are eligible under Clean Development Mechanism, there are certain restrictions in selection of technology and usage of MSW. Therefore the project developer should not neglect these aspects while developing the projects to get CDM CER revenue.
Mass burning, gasification and pyrolysis are also used as other options for power generation from MSW. For services related to MSW to power, contact us.